Welcome to my guestbook, where you can see what previous visitors think about this site and my projects and articles. Many thanks to everyone who has left messages - your feedback really is appreciated!

All guestbook entries (395)

    • Roberto Rossi
    • Etyek(Hungary)
    • 21 March, 2022

    Hi Mark.
    Many thanks for your work.
    It made me reconcile with the Musical Fidelity A-1. You have guided me step by step in making the use of the volume pot acceptable without excessively changing the personality of the MF.


    • James
    • U.K
    • 1 November, 2021

    Thanks for your great website! My love affair with the MF A1 began when I saw 2 x old amps lying on the tarmac at a car boot sale over 10 years ago. Upon investigation I saw a scruffy old Cambridge Audio amp - and the very dated and unusual looking A1 which I had never seen before. I was impressed by the 'Made in England', the hand written serial number and the weight of the unit and I asked what he wanted for them to which the gentleman replied ' a tenner for the pair'. I offered him £7.50 for the pair (you have to haggle lol) and he accepted!

    When I got them home the Cambridge Audio worked but was quickly forgotten when I fired up the A1 - wow! - what a beautiful sound through my Mission 753's. I was blown away by the presence and depth especially after it the unit had warmed up! I have a MF A100 as my main amp now but the A1 is always on standby! I swear it still sounds better than the A100! This was and still is the best purchase of my life and I feel embarrassed for having haggled the guy down from £10!

    Thanks again for having such an excellent resource available for everyone!

    • Lucas Toledo
    • Pelotas, RS, Brasil
    • 5 July, 2021

    Great projects, high carefully and beaty. Congratulations by this website!

    • Arthur Manolopoulos
    • Sydney, Australia
    • 26 May, 2021

    Greetings from 'Down Under'!
    Thank you Mark for a wonderful 'trip' down memory lane.

    A pair of LS7t is keeping me entertained as I scribe these lines and, although I also have a pair of large Thiel CS6 towers, I find that the 'good old' Rogers are being used much more than the large Americans! Especially for night listening at modest levels, they are simply, Magic!
    Planning to replace all capacitors in their crossovers soon and I take your advice not to look for expensive alternatives.
    I will stick to good quality electrolytics as you suggest.

    Thanks again for sharing all this information with the rest of us.
    Best regards!

    • Tony H
    • Bristol, UK
    • 21 November, 2020

    Hi Mark,

    Like many other visitors, I linked to your voltage reference articles from eevblog, and found a wealth of valuable knowledge and information! Many more hours to be lost reading things on your web site I fear...

    Our backgrounds are not dissimilar, I also had a Garrard 2025 and mended or stripped many electronic things as I grew up. Also worked in broadcasting, so very familiar with LS3/5a BC1 Eng Inf etc, but drifted into IT by the mid '80s. My old web site went when Freeserve folded, but I have a small one at for those repairs I feel might help someone else or save some landfill.

    Thanks you for documenting your labours - as you say in your 'About' it can be very time-consuming - especially the budget multi-meters.

    Stay safe - Tony H.

    P.S. I was never keen on the BC1 for speech - much too harsh in the middle frequency range. Superb clarity with orchestra though!

    • Karl
    • Towcester, UK
    • 28 October, 2020

    Firstly, a big thanks for making the information regarding the Music Fidelity amp available, it is an excellent resource. Secondly, having bought an amp several years ago, with a very noisy volume control, I implemented your pre-amp mod which was very easy to make and install. This, coupled with replacing the PSU capacitors, has transformed the amp making it very quiet, much more musical with solid and clear bass; it quite a revelation! So my thanks once again.

    • Steven Zounis
    • Sydney
    • 25 October, 2020

    I have a pair of Rogers Studio 1 speakers purchased new around 1983. I still use them and still cannot find another pair of speakers of the same sound quality. I enjoy watching my teenage daughters reaction to the sound quality when listening to "real" HiFi! It is more of an experience and not just listening to music. I was interested in your website reading about Rogers speakers. I am always thinking of an equivalent replacement if ever my speakers fail. What I have come up with is a pair of Harbeth Monitor 40.2 loudspeaker's which I am prepared to fly to the UK to audition! I still listen to vinyl and CD's. Thank you for an interesting website!

    • Nicolaas Krugell
    • Witbank
    • 5 October, 2020

    Good day

    I highly appreciated your website thank you for all the effort and years of work dedicated to this website

    Kind regards

    • Singapore
    • 27 August, 2020

    Dear Mark,

    I happen to stumble upon your website in one of the diy audio forums. Your website is very informative and your photos are high resolution which are rare for diy audio websites.

    I'm presently recapping my NAD3240PE amplifier, and also completed doing the same thing for my older NAD7155 FM Radio integrated amplifier (the FM tuner is dead already!).

    I only read your section on multimeters so far, and find it very helpful, as I used that to help me decide on my purchase of a new RS PRO multimeter.

    I'm a diy audio hobbyist, starting to tinker around with PCBs, soldering, learning to read circuit diagrams and taking apart electrical appliances and old radios since pre-teen years....

    I'll look through your other sections and I'm sure I will find them interesting.

    Many thanks for sharing your experience and technical knowledge!

    Best regards and take care!


    • Jonathan Bliss
    • Roscommon, Ireland
    • 23 June, 2020

    Hi, I always happen upon your page when I Google for ATC SCM20's. I used to own a really good pair myself, I loved them.

    Had several amps with them including a pro amplifier - MC2 Audio MC650 - 350W. It really worked with them, filling out the soundstage more so than other amps I tried such as the Michell Alecto mono blocks.

    Alas, I decided my room was too large for them, so sold them on for some large JBLs, probably too large now.

    If I ever found another nice pair I might just have to go for them again.

    Love the fact you are so knowledgeable about such things and even building your own amps. Must be very satisfying.

    All the best, Jon

    • Nick
    • W Wales
    • 19 June, 2020

    Fab resource!
    Lots of reading to be had
    Have bookmarked, will return.

    • Duncan Lucas
    • Scotland
    • 17 June, 2020

    Like you my first "quality" record player was a Garrard 2025TC, I too changed the ceramic cartridge for a MM one.

    We hold the same interests although I think I am a bit older than you---old engineers never die they only fade away.

    • David
    • Wakefield
    • 5 June, 2020

    just thought I'd have a look at your website and then spent a couple of enjoyable hours going through it! I particularly enjoyed reading about your Hacker volume control repairs and your NICAM decoder project!

    • Steve Faulkner
    • Kansas City, USA
    • 28 May, 2020

    Mark, thanks much for this site. It's tough to find much technical info on these old amps, much less anything so well done. I've got an A100 that I purchased in 1987. It hasn't seen much use since the late 90's, but still runs like a champ. I'm going to spend some time over the next few months updating it, and the info you've provided will be more helpful in that effort than anything else I've found...and infinitely better than what Musical Fidelity was willing to provide (that is, zero).

    • Al Davies
    • Glasgow, UK
    • 15 May, 2020

    As a beginner in electronics I found your site very useful. I'll be delving into op-amp cicuits soon so every little bit of knowledge is a good thing. Thank you.

    • Hector Plain
    • England
    • 17 January, 2020

    What a superb site. I stumbled on this whilst looking for info on my beloved Hacker RP25. Mark I think you would make a smashing teacher or author of technical books. The ability to convey intricate detail whilst maintaining interest is a rare skill indeed and you have mastered it.

    The writing style reminds me of my favourite electronics book, Principals of Electronics by Colin Simpson, no big words or anything too clever just important information delivered in a digestible manner.

    • cliff
    • Canada
    • 12 December, 2019

    The clearest intro tutorial to op-amps that I have ever read! great!

    • Anastasios
    • France
    • 6 November, 2019

    Your site is the most insightful, exciting read since Douglas Self's Small Signal Audio. The breadth and depth of knowledge here is awe inspiring and plain inspiring. Thank you so much for sharing and keep up the great work.

    • Ciro
    • Brazil
    • 16 August, 2019

    Mark, thanks for your effort to keep this site up and running and your time providing us very nice reviews. I was looking for a new multimeter and Google brought me to your reviews. As a fellow engineer and tinkerer, I share your interest in diy projects in my (scarce) spare time. Best wishes and good luck.

    • Peter Berry
    • Cornwall
    • 10 August, 2019

    Arrived here whilst looking for review of multimeters. A pleasant surprise to find a simple impartial informative site full of items of interest. The Hi fi section especially, I too have the Thornes 125 Mkii with SME and Shure V15, purchased way back in the 70s and still performing, with the Sugden C51 P51 amp combo among others. Great site.

    Best regards,
    Peter Berry.

    • James Struble
    • Kansas City, MO, USA
    • 2 May, 2019

    Thank you, your site has brought life back to my A1.

    • Ray Dart
    • Beds
    • 24 March, 2019

    Really interesting and useful article (I found by accident when searching for information about the AF116). Thanks.

    • Carlos
    • Brazil
    • 4 January, 2019

    Congratulations on the great site, with well documented information, approach to useful equipment, good vintage blending to microprocessors. I really enjoyed the review of the AD584 voltage reference kit. I wish you success in your life and accomplishments.

    • Dave Patterson
    • Pacific Northwest, USA
    • 30 December, 2018

    Mark, Great site!
    I found it while looking for some basic information on PICs. Your PIC section really helped me finally wrap my head around the way timing works. Thanks!

    I look forward to perusing the rest of your site as time permits. The Hi-Fi and electronics sections are of particular interest.

    • The Real Davey Crockett
    • usa
    • 26 December, 2018

    WOW Radio Shack went out of business but I have found all these wonderful folks like mark moving beauty and music forward. and the soft style of writing gives me Zero Listening Fatique

    Wow Mark where is the donate here button.

    Another fan


    • Peter Geisler
    • Germany - Sachsen-Anhalt
    • 5 November, 2018

    Very usefull hints for buying the right reference modul for my hobby - at the moment it is a rf power meter which needs a stable reference point for reproducing reliable results at all.
    Thanks for publishing your ideas and work to find that out.

    • Aki Turan
    • London
    • 18 June, 2018

    Thanks Mark. Great site. Clean and uncluttered. Informative without being too obscure or simplistic.

    Am a proud owner of a MF A1-MK2 that needs a service. Usual problems. Your site will help in what I'll do with the amp when time permits.

    Again, cheers. Would buy you a beer if in London.


    • Mark
    • Midlands
    • 17 April, 2018

    Thanks for your interesting and informative piece on the AD584 voltage references. I received mine from China this week, the cheapest one for £3.50 delivered.

    I was surprised to find the board had an LH version device as it was discontinued in 2012 yet mine is date marked 1640, and the 'test certificate' is dated 2015. LOL!

    I love all this chinese stuff, what a joy for curious electronics hobbyists...

    • Jerry Ervin
    • Michigan, USA
    • 7 April, 2018

    Your site was very recently recommended to me and I'm checking it out now. Thank you for being here!

    • oscar
    • llanelli carms
    • 14 March, 2018

    A great trip through memory lane...Very absorbing and interesting effort. Thank you! I am on my 70s but still enjoying the "reviving" of the occasional "patient"!
    At the moment I am trying to find "SFT" type transistors having here two sets made in Italy in the 60s. A task rather difficult to perform especially when there are no markings on the little blighters. Thanks again: you have one more follower.

    • Troyte
    • Worcestershire
    • 12 March, 2018

    A well-presented website having a clear layout that includes photographs of exceptional quality. In my view, the most important aspect of all is that the pages are written in a style that makes the information easy to understand. This is because it's underpinned by first-class grammar, systematic formatting and proper punctuation.
    Thank you, Mark :-)

    • Rudy van Stratum
    • Netherlands
    • 17 January, 2018

    I'm a diy fan and longtime builder of diy musical fidelity A1 A100 A1000 and so forth. I got the copy of the A1 circuit in 1991 from the Dutch importer of MF stuff (but had to keep it secret!). It was Mr Hennessy who for the first time wrote publicly about the A1 and revealed its schematics from own research! Since that time I recommended this site to many friends for advice and explanation.

    (BTW still puzzled about the claim of TdP about the 20Watt class A claim of A1 with only 700mA standing current, but in the end he IS the designer, so ....)

    • Juan Jose Alvarez
    • Leon - Spain
    • 11 October, 2017

    I've been reading some of your articles and I've enjoyed them a lot. Thank you for your efforts to divulgate your knowlegdes in electronics. There's many hours of work behind. I know well what I'm talking about as I have a blog about electronics too.

    • Richard Nelson
    • Mesa AZ (Sonoran Desert)
    • 6 October, 2017

    Excellent job at providing the details not easily found elsewhere. I have ordered an AN8008 as recommended by a friend. It has some nice features but the "dead zone" of ± 5 Uv is a bummer.

    Keep up the good work.

    X < > Y,

    Richard (Calcfan)

    • Bob Marting
    • Yorkshire
    • 1 December, 2016

    I found your page by accident looking for information on AD584 voltage references - your reviews were useful.

    I ordered one of the type 2 you reviewed and received exactly the same photocopied "calibration certificate" :) ! The actual module was the 'L' higher spec version which was good.

    That said, having paying £3.56 including delivery from China I was more than happy and it served it's purpose in checking the accuracy of a number of analogue automotive workshop instruments. The accuracy of the module was fine for the purpose.

    nice website


    • George Dougherty
    • Belfast
    • 12 October, 2016

    I found your pages on the PIC programming very helpful and cleared up some problems I had when I first tried to program them. My interest in PIC programming came from building an emulated version of Clive Sinclair's first computer that I owned years ago but decided to throw away. After regretting my decision I built the emulator but wanted to understand more as how this is done. My difficulty came from trying to understand the .asm file that came with the circuit diagram. My electronics experience made it very straight forward for me to build the emulator, but struggled badly to understand the op code in the .asm file. But I find it particularly ironlc that a Harvard type PIC was emulating a Von-Newman type processor from the late 70's. Anyway thank you so much for your detailed walk through what seems a simple 4 bit counter, but to emulate this using a PIC uncovers so many programming mechanisms that I will use in my exploration into PIC programming. Can't wait for the next instalment.


    • Simbarashe Antonio
    • Australia
    • 25 May, 2016

    Highly informative and educational. As a novice in programming it is a very good foundation and a stepping stone in my personal development. keep up the good work

    • Gerald Larooy
    • Christchurch, New Zealand
    • 11 May, 2016

    I liked the stuff about germanium transistors and would like to know more. I wonder if germanium has anything sonically relavent?

    • fishdroid
    • USA
    • 24 January, 2016

    I find your site very interesting and informative. I go back to the days when there were many DIY electronics shops in existence. Radio Shack and others supplied complete plans and kits for all manner of DIY electronics projects including amplifiers. With the exception of some VERY expensive quality manufactured amps the only way to obtain "real audiophile quality" stereo components was to "roll-your-own" using tubes instead of solid state devices. Some people, even today, prefer the sound quality of tubes over solid state. Problem is, finding the tubes and replacements. Anyway, now you all have an idea how old I am. Long live the Who, Led Zeppelin, and the Rolling Stones!!!!!!!

    • Chris
    • Cambridgeshire UK
    • 15 January, 2016

    Wow !
    Many thanks for posting up your findings and experience on the failures of old Germanium and silicon transistors. Fine work. Luckily Germanium devices are much more robust than they are given credit for. Long live Germanium !

    • Mark Beatie
    • USA
    • 4 January, 2016

    Great write-ups on the gainclones and speakers. I've read your site over the years and have always loved rereading your audio designs.

    Cheers and happy 2016!

    • EJIRO
    • Abuja, Nigeria
    • 4 January, 2016

    Thanks for your page. You did a lot of clarification on the subject. I am so much interested in PIC and want to make it a hobby.


    • Stew Nelless
    • Alberta, Canada
    • 23 December, 2015

    Great pages. I remember when I was looking at power supplies for Airpax equipped turntables (like the LP12) and stumbled across your pages. Always informative. I stumbled her as a result of searching for links to the Musical Fidelity A1 and similar amplifiers (even the Sugden A-21). As always a great resource.

    • Narayan Gokul Lakariya
    • Bhagur, Nashik
    • 12 December, 2015

    I liked your website and thanks for your step by step explaination of PIC16F84A microcontroller programming.

    Your website is best for the begineers who can develop himself just by reading your site.

    • Sidney Lellis
    • Brazil
    • 9 December, 2015


    Thanks to share your experience to us. Very good site.

    • Henry Chan
    • Las Vegas, NV
    • 4 December, 2015

    Hi Mark, thank you for posting such detail article on A1, otherwise no one seems to know anything about this incredible little amp. It is old, but one solid A1 X integrated class A amp.

    • John
    • Isle of Wight
    • 26 October, 2015

    Great website written in a style that even I can understand. Keep up the good work Mark.

    • Tom Jennings
    • London
    • 30 September, 2015


    Really enjoyed your website occasionally checking to see if there have been any updates. First stumbled on it around 10 years ago and have since gone on to study Electronic Engineering and start a career which unfortunately has nothing to do with electronics or engineering.


    • Totley Rover
    • UK
    • 24 June, 2014

    An excellent web site.
    Enjoyed reading through the PIC tutorial.
    I will go back to it once I've got my PIC dev board setup.
    Very much a "retro" electronics hobbyist.
    Started out in 1975 with Veroboard and Practical Electronics projects.
    Built a Nascom 2 which kicked off a long career in real time embedded software engineering.

    • Les Clarke
    • Worcestershire United Kingdom
    • 3 June, 2014

    I think your site is well designed and informative, As someone who really enjoys assembler it is good to see given the world seems obsessed with Arduino... Regards Les aka 22swg

    • Miko Zoltan
    • Hong Kong
    • 24 May, 2014

    Thanks for this excellently revised web site. It is people like you that make the Internet valuable and knowledge spread much faster!

    • choo
    • Kuala Lumpur Malaysi
    • 14 May, 2014

    Excellent write up on the Roger LS 5/9. Thumbs up. However, just to clarify, a properly set up LS 5/9 with good amplification can produce bass & clarity that is unmatched by speakers costing 5 to 6 times more and I have listen to a number of pretty expensive setup before (including some TAD, Focal Grand Utopia, Wilson etc). Best regards.

    • Philip Rutkowski
    • Crowthorne, UK
    • 4 May, 2014

    Hi Mark,

    Many Thanks for your inspirational coverage of the LS5/8's, this has lead me to perform my own project for a pair of cabinets without the AM8/16 amplifiers with great success, I have since exhibited my finished project at the Hi-Fi Wigwam Scalford show with a surprising wealth of good feedback, for this I am very grateful for the invaluable details on your website!

    I was thinking of making an OP-AMP version of the crossover, but it seems this was already done! I had no idea there was an AM8/21 in existence!

    I'll be checking back if you have any further info on the AM8/21... until then, keep up the good work ;-)

    Thanks Again!


    • Kelvin Naylor
    • Northampton and Qatar
    • 29 April, 2014

    What a tidy and comprehensive site.
    Superb work as well
    I will also be returning to digest more.
    Thank you so much

    • Larry Gold
    • West Texas, USA
    • 28 April, 2014

    I just stumbled upon your terrific website, precisely the "PIC" portion describing programming among other topics.

    It never seems to amaze me that the better tutorials and information regarding all facets of the PIC Micros come from other countries other than the USA. Our educators don't seem to put a great deal of emphasis on microcontrollers or electronics (until the college level.) By contrast, math begins in the early grades of schooling.

    I'm having difficulty at times grasping the programming aspect of PIC's which leads me to the following. Since each author of PIC tutorials writes in his or her manner and doesn't know my limited knowledge, I gain some additional info but I don't feel I have yet mastered it.

    Your information is quite detailed, but so easy to understand and offers so much more that I can't stop reading it. I thank you for myself and others who are fascinated by the PIC for sharing all this info free of charge.

    Larry Gold

    • Gennaro Piscopo
    • Sydney, Australia
    • 19 April, 2014

    Excellent website, I've used this site over many years and have only just returned prior to purchasing my second pair of Rogers speakers. I'm now the proud owner of the Studio Ones and LS6.
    Unfortunately the LS6 have a blown bass driver. Hopefully I'll be able to get them repaired. Your website has been enhanced and is not only well constructed but the premier reference site for the vintage Rogers brand.
    I commend you on your attention to detail.
    Should you require any photos, please let me know.

    • Chris Spreckley
    • Manchester, England
    • 8 April, 2014

    Great site as I am just learning PIC Assembler at the age of 74.

    • Helder Pinheiro
    • Stockholm, Sweden
    • 6 January, 2014

    I have just read about Your Gainclone Amplifier.

    I am thoroughly impressed by Your impeccable attention to detail, your knowledge and craftsmanship.

    I could not stop before reading the hole project, and I will come back to enjoy more.

    Thank you, from my heart!

    • Rafael Augusto
    • Brazil
    • 6 January, 2014

    Thank you so much for the amazing courses and instructions. You write in a very comfortable, detailed and yet easy to understand manner.
    Good luck in the next steps for the website!

    • Jim Hagan
    • Dagupan City, Philippines
    • 14 October, 2013

    Thanks for a great site. This is the best site I have been on for instruction, code that compiles and works.
    Looking forward to your applications.
    Very best regards.

    • William Lee Parks
    • London, Kentucky, U.S.A.
    • 13 September, 2013

    I have owned both the Chartwell LS3/5A and the Spendor LS3/5A Spendors (and still do). I use a custom made tube preamp and power amp to drive them. I love the sound. I just acquired a pair of Spendor SP1's. They take the sound of the BBC developed speakers a step higher Mr. Spencer Hughes was by any measure a very brillant designer who knew well the sound of live music and how to design and build speakers capable of reproducing that elusive sound. It is a shame the speaker design lab of the BBC is no more.

    • isuru
    • 24 July, 2013

    Your super man.i like your all project. an try LM4782 amp. i am srilnka. sorry no understand english language. understand simpel english

    • Paul
    • uk
    • 7 July, 2013

    Hi and many thanks, don't know if you're still active on this site but i'm begining to try to learn pic programming and your site has been by far the clearest start i've come accross

    • Jose
    • Mexicali, Mexico
    • 6 July, 2013

    I'm starting with pic's and this is a good place to start. Thanks.

    • robert woodliff
    • London, the one to be found in England.
    • 28 June, 2013

    Ref:- Rogers dB 101
    Mark, Thanks for putting up the great inside & out review of the lovable, if rather directional speakers. I have three pairs, two sets run as a set, due to their impedance value & the third run with a Cannon vertical speaker set (sound quality no were near as good), to get over the directional nature of the Rogers.
    One minor question, any idea how to clean the exposed cone without damaging it? Ok I've had them for 15 years (?) and I've tried to resist the temptation, but the girlfriend is itching too, and before they are dusted into oblivion any advice? ...... other than become celibate!
    Regards Bob

    • Pervez Akbar
    • United Kingdom
    • 14 April, 2013

    I have been trying to learn about programming for the past 10 years. There aren't any books which will take you through step by step like this one. This has encouraged me to learn more.
    I have book marked your website and looking forward for any updates

    Best regards
    Pervez Akbar

    • geevar
    • India, Kerala
    • 11 March, 2013

    u lightened in to my PIC programming environment........ Any way thanku so much.....!

    • Roger Adams
    • Eastsound, WA, USA
    • 19 January, 2013

    Thanks for the articles on design and building gainclone amps. Very helpful to understanding what makes it work.


    • Mark Kaye
    • Melbourne, Australia
    • 17 January, 2013

    Thank you Mark for all the valuable information on the MF A1.

    I have owned mine since it was new in 1989, and I took the plunge and opened it up yesterday. The tansformer was completely unsecured, and one of the 10000uf caps was rolling around. The other three have bulges and look ready to explode.

    Amazingly, I have been using the amp regularly, and I was oblivious to the problems lurking within.

    I shall now start the restoration process, replacing the electrolytic caps and the pre-amp as per your recommendations.

    Thanks once again.


    • Michel Desrosiers
    • Joliette, Qc. Canada
    • 1 December, 2012

    Thank you Mark.

    Very useful. I own a A1 since 1989. I have a problem actually, i don't know exactly what it is, but with your drawing i will find the trouble more easily.

    Thank you to take the time to build this website!


    • Constantiu Soare
    • Bucharest, Romania
    • 29 October, 2012

    Hello Mark,

    Congratulations for your web site!
    After successfully building a DIY air bearing tonearm for my turntable, the next step was to build a decent power amplifier.
    Your Micro-Amp seemed to me the best choice. And indeed it was!
    I used your schematic (except the mute/thermal protection). For the power-on mute I used the simple circuit from the TI LM4780 data sheet which works fine.
    The amplifier worked fine from the first power-on attempt: no oscillation, no hum, just MUSIC


    • Laurence Gibbs
    • UK
    • 24 October, 2012

    Hi really enjoyed the info on the Musical Fidelity A1. I had one from new and had a diode in the bridge rec fail when it was a few years old. Can't remember what i replaced the diodes with now but it was for something a little better quality (i worked for the now defunct Mastercare as a TV & Radio engineer at the time, just out of my apprentiship). Sadly i sold the A1 (big mistake). So I keep looking for one on Ebay at "the right price".
    Thanks for the interesting read.

    • Tim Lim
    • Georgetown, Penang
    • 30 September, 2012

    Hi Mark,

    Great work. I stumbled upon your site when I goggled for BBC LS3/5A. It is a shame the other models of BBC are not as well known outside of the UK. The current owners of Rogers, whom incidentally is based in my country, should really revive those other models.

    Best regards,

    • cyrille
    • arnhem, netherlands
    • 27 September, 2012

    great site!!! thank you!

    got a pair of p-20's, got a brochure pdf if you want to.

    groetjes Cyrille

    • john
    • Marietta, GA
    • 10 September, 2012

    Thanks for the editor tip! I've been using metapad which is useful and I like it but not especially designed for code. So far I like ConTEXT and its loaded with options and customization features.
    You may be curious about some of my work, if so, here's a sample:
    Enjoyed your site.

    • Graham Tait
    • Edinburgh
    • 11 August, 2012

    I wish I could organise my garage like yours! Much admiration.

    • Norman Jackson W7NRJ
    • Near Seattle, WA, USA
    • 6 July, 2012

    Electronics hobbyist, ham radio operator, just getting in to PIC's, found your site. Your writing style makes it easy to understand, minimum mumbo-jumbo techie talk. I appreciate your effort to help others understand PIC's.

    • John
    • New Zealand
    • 1 June, 2012

    Thank you for the write up on the differences between non-inverting and inverting gainclone and the value recommendations for the resistors, it has been of great help. Kudos on writing it up in such a clear and simple way that's easy to understand.

    • ranulfo ymbong
    • philippines
    • 7 April, 2012

    Hi, i'm happy that you shares your knowledge about pic micro-controller to us, i find it very useful. thank you very much.

    • Paco
    • Spain
    • 14 March, 2012

    Hola amigo:

    El blog web es excelente. Multitud de informes y bien redactado.

    Gracias por ayudarnos.

    • mauricio marotta
    • BRASIL
    • 14 March, 2012

    Dear Mark.
    Thank you.
    G b y.

    • Kelvin Turner
    • Oxford
    • 26 February, 2012

    Hi Mark! Great site. I want to thank you for all the info. and tips you have here. They helped me enormously. Here's what I just posted on the DIY audio site..."Hi all! I have just completed a replacement programme of all the electrolytic capacitors in my MA50 monoblocs and WOW what amazing amplifiers these things are! I remembered them being praised to the skies in the days when they were available new (mid eighties) in magazines like HiFi Answers. At that time I could not afford such luxuries, but when I found a pair of these on ebay I bought them. I listened and thought I had made a mistake, but then I found Mark Hennessy's site and followed his advice about swapping the electrolytic capacitors as a first step to rejuvenating the amps. I have never done anything like this before, but i managed to work out how to make the changes and executed the soldering with great care (the circuit boards are old and the track has a tendency to come away some times). The results are FANTASTIC! I will post a list of the capacitors I used on Mark's brilliant site in a kind of homage to all he has done to help me. Good luck!"

    I would like to send you a list of the capacitors I used in case it helps anybody else to make the improvements I have. Could you let me know how? Cheers. Kelvin.

    • Roberto
    • Italy
    • 19 December, 2011

    Greetings from Italy !

    I'm building a digitally controlled preamp too (but using an ATMega processor and a 320x240 color touchscreen LCD) and your site has been very inspiring for me.
    Keep up the good work !
    Best regards.

    • Mike Holland
    • Sydney, Australia
    • 16 October, 2011

    Hi Mark,
    I am searching for a little advice/help on my problem with my mag pickup equalisation stage. I am running a LH Class A amplifier with the pre-amp that he produced for his 75 watt amplifier. Recently I stopped getting any bass with my records, in both channels. First thought was that the earth connection was broken, and I was just getting the difference signals for the two channels, but everything checked out fine. I have tried a different pickup cartridge, to no avail.
    My "Stereo Checkout" disk indicates that I am getting nothing below about 200 c/s in either channel.
    Do you have any suggestions what could cause this? Any component failure should only affect one channel, unless it is in the power supply!
    Any help gratefully received.

    • gerald a estes III
    • olongapo city, philippines
    • 13 October, 2011

    greetings mark,

    10/13/2011 @ 9:35am local time... WOW! fantastic! your projects are truly inspirational!

    found the site searching 'powered speaker circuit design'.

    what you have here is a u.s. licensed architect / design firm, relying as of late on design/build woodworking projects wishing to thank you.

    5's acrost the board regardless of the ck'd items.


    • mike
    • UK
    • 3 August, 2011

    Hi Mark

    I was very interested to read the views of everyone on Rogers speakers.I heard a pair of LS6s demonstrated in 1986 at Cambridge and bought them on the spot to use with my Quad 405-2 power amp and Quad 44 preamp acquired at around the same time. It was a marriage made in heaven and still use this amp/speaker combination today. Admittedly I had originally intended to upgrade the speakers when funds allowed, however over the years I found the necessary financial outlay unjustified by any apparent improvement in sound quality.

    At the time I heard them demonstrated against Tannoys and Spendors and found the Rogers a good balance between the bass performance of the Tannoys and the top end performance of the Spendors. This sounds like my choice was a compromise but it wasn't, as proven by the test of time!

    • Guritno Djanubudiman
    • Jakarta, Indonesia
    • 5 April, 2011

    Nice project you have.
    How do you explain, how/where the subwoofer/bass lower frequencies are being separated on your circuit sector?

    Thanbk you
    Best Regards,

    • sir lord keith
    • rochester kent
    • 16 March, 2011

    nice one dave in hornchurch for repairing my ls33 rogers speakers i was quoted £300 from a local engineer thanks to marks project page i found a link for dave smith of dk loudspeakers hornchurch who i found to be a speaker wizard of the highest order a truley nice guy who magiced my lovely speakers back to life for £20 with spare parts he had in stock 24hr service .....what a guy...cheers man..sir .lord

    • Radoslaw
    • Warsaw, Poland
    • 1 January, 2011

    Dear Mark!

    Thank You for your time and patience in doing this site!

    I know many people with true passions and I admire it, but sharing hard-gained knowledge with other people is even something more!

    Take Care!

    • Howard M
    • Birmingham, UK
    • 29 December, 2010

    Excellent PIC primer, dude - having got the hang of Arduinos and AVR stuff, really wanted to have a go with PICs but it all seemed waaay too advanced until I came across these pages. Many thanks :)

    • gokul
    • India
    • 28 December, 2010

    PIC programming article is so good for beginners.
    i request to add c programming article for PIC 16,18 series.

    • Wayne Robinson
    • UK
    • 12 December, 2010

    What a brilliant website, I am just starting with PIC Programming and to read something that assures me I am taking the right path is really great :)
    Thank you for sharing your work & experiences

    • viren
    • India
    • 26 November, 2010

    Started working in my head on a preamp using the PGA 2310, so this site is going to be looked up pretty often! Lots of interesting ideas here. I too chased the 5-gang mech. pot with servo control dream. The major problem with pots is the noise that gets out of hand with time.

    This is for a 5-ch version of the Leach amp. I built some time back.

    I do some woodworking too!

    • keith
    • rochester kent
    • 21 November, 2010

    fantastic result from dave in romford i would recomend this guy to anyone who has a damaged speaker very quick and cheap and alovely bloke thanks a million keith

    • Rein Gortemaker
    • The Netherlands
    • 9 September, 2010

    Thank for your collection of work. I recently became a proud owner of LS6 set.

    • Francis Janurius
    • Malaysia
    • 11 August, 2010

    This is the first time I am coming across such a complex preamp. It has completely blown my mind. I may not be making this design, but it has certainly inspired me to carry on with my DIY audio work. I have been stagnant for a number of years, as components are easy to come by over here.
    keep up the good work.




    • rkelly
    • San Francisco
    • 4 August, 2010

    thanks for itching the scratch that so many of us have as found listeners of our Rogers speakers. Your conclusion of the sound quality of the LS5/9 was spot on. Love my LS2, LS6 & LS5/9's. Don't have enough rooms in the house for any more.

    • Col
    • London, UK
    • 18 June, 2010

    Wow, thanks for the detailed info, you have explained so much so clearly.

    • Darijo Sundov
    • Croatia
    • 25 April, 2010

    Greetings from Split,Croatia !
    I'm proud owner of a Rogers Studio 1a.
    Your web site is very informative about old Hi-Fi.
    If you have any review about Rogers loudspeakers please ?
    Thank You and Best Regards !

    • A. Rodgers
    • Kent, UK
    • 8 April, 2010

    Mark - just to say thank you for the extremely well written and genuinely helpful and interesting PIC getting started guide.

    Looks like the pages haven't been updated for some time, so I won't hold up much hope of the 'applications' section being completed any time soon!

    But as an introduction to PIC programming, I found your guide invaluable. Thank you.

    • TAnh
    • VietNam
    • 8 March, 2010

    I want to say THANK YOU so much!
    I saw this web by chance. Something you've colected help me much

    • Thomas
    • 25 February, 2010


    Thanks for your good job in expressing and teaching on writing simple program for PIC.

    • Amith Prasanna
    • Sri Lanka
    • 21 February, 2010

    this is a great site. it is very useful for bigenners. thankyou very much. wish you for all success.

    • Omar
    • Washington DC
    • 7 January, 2010

    Great website, Mark! I programmed PICs in college for an Embedded Design class, and thought I'd get back into it recently. Your beginners assembly tutorial was a great refresher. Thank you!

    • bosco
    • Eire
    • 4 December, 2009

    Loved this site, great info on PIC thank a million mate.
    Much appreciated slan abhaile. (bye)

    • ranjit wimalasena
    • Toronto, Canada
    • 29 November, 2009

    your site is informative and is well presented. i have 2 pairs of rogers, one is a rogers monitor 2 (8 bextrene woofer, a celestion tweeter and a coles super tweeter) and the other has no lables and the covers are impossible to remove to look at the drivers. both are fine speakers and i use the one without lable as my main hifi speaker.

    i have come across an other rogers speaker called the rogers monitor 2 (this is on the badge). it has a clear polypropalene 10inch woofer, a tweeter and an other tweeter. the cabinet is about 35hx15wx17d inches. i cannot find any info on the web any healp from you would be greately appriciated. if you like i can send pictures of all 3 speakers. many thanks.

    • Ade
    • Lagos, NG
    • 19 November, 2009

    Thanks for this simple and straight forward guide.

    • Tom Hatton
    • Orpington, Kent
    • 12 November, 2009

    Hi Mark. What a wonderful, site with so much fascinating information. Just really wanted to let you know that I'm a recent owner of a pair of LS 7's (2 weeks) and so, I was delighted to find your site and discover the fact that you possess the same speakers.

    I aquired my LS 7's from a charity shop for twenty quid after I practically fell over them.....

    I slowly removed the grills...and there they were! LS 7's!!

    I asked the man in the shop " much do you want for those old speakers on the floor" ? ...and he said £20. I bit his arm off, rushed them home in the car and connected them up....with my heart beating like a little kid...I'm 48!

    They work perfectly, Mark. Happy days!

    • Tormod
    • Bergen, Norway
    • , 2009

    Great site!

    I have built an audio amplifier, but your design just looks so superior! The idea of using a microcontroller for the circuit safety and using a light for fault indication is super!

    • Matt S.
    • Naples, FL USA
    • 1 October, 2009

    I have been searching for quite some time for a clear beginners guide to PIC programming.
    I finally found it here.
    Thanks for all your efforts!

    • Geriatric Sod
    • Melbourne, VIC, Australia
    • 16 September, 2009

    Love your site! It's a good find after trawling the internet looking for DIY Audio projects...

    Just wondering why your pre-amp uses switching relays for input switching, instead of one of Maxim's semiconductor audio you reckon that might be the way you would design it if you had to do it all over again?

    Thanks again!

    • Karel Chlebek
    • Glasgow
    • 1 September, 2009

    It's a great site. Entertaining, well-written and informative. Being a former electronics buff myself, I enjoyed your articles, especially the audio ones - you definitely don't need a "Who writes this crap?!" option. I feel a little inspired to get back into it all - thanks!

    • Ho Petrus Aswin
    • Google Search
    • 26 August, 2009

    I like this PIC site very much, therefore I'd like to thank Mark for his Good Job.

    • Martin Smolka
    • Czech Republic
    • 13 August, 2009


    • John P Coates
    • SE England
    • 12 August, 2009

    I really like the layout of your site and find it most inspiring. You've got some interesting projects on the go. I intend to re-visit this site from time to time. Keep up the good work!

    • Perry A. Leaves
    • Beavercreek, Ohio
    • 20 July, 2009

    Thanks so much for your PIC programming page!  I have been trying to teach myself to program the pic16F84a using the literature available on the Microchip web sight.  All of the examples they have available raise more questions than they answer making the learning process very difficult.

    The examples on your web sight answered relevant questions as soon as they arose and in very good detail.

    I will continue reading microchips literature but it will be much easier after reading through your examples.

    There were a couple of obvious typing errors in the examples movwf instead of movfw.  The code was explained well enough in the commentary that it was easy to see the mistake in the code example.

    I really feel I have learned a great deal in a short amount of time from reading your section on PIC program.  I have literally spent days reading microchips literature and felt like I was no closer to programming a PIC then when I started.  After all the reading I did I did not understand the basic structure of the .ASM file or what the include file was for.

    Thank you so much!!

    • Ian Wester
    • Swindon - work
    • 15 July, 2009

    Hello Mark,

    Just a quick note of appreciation for your website. I found it when looking for a basic PIC tutorial.

    I also spent 3 years running an PA sound and light company so the Audio stuff was a worthwhile distraction.


    • Richard
    • Sussex
    • 9 July, 2009

    Nice to see that the site is still accessible but guest book sparse over the last couple of years. So thought I would add a comment in 2009.

    • Nagesh
    • India
    • 29 June, 2009

    Excellent website for those who want to get into embedded world.......:)


    • Dewald Haasbroek
    • Pretoria, South Africa
    • 27 April, 2009

    Thank you Thank you, This really helped me to get started in the wonderful of microcontrollers.

    The site was easy to read and the downloads(the quick refrence sheet, and the default program lay out) was of great help to me.

    Hope to see more of this A-grade stuff on your web page

    Dewald Haasbroek

    • sameh medany
    • Cairo, Egypt
    • 18 April, 2009

    dear mark,

    a lot of thanks for creating this great web site for teaching beginners like me, and i hope to provide more examples on how to program PICS and how to link a PIC with an xbee modules

    • sidd
    • Calgary
    • 31 March, 2009

    this site is very helpul for young begineers to cope with their starting problems and know the basics of PIC instruction set

    • Gireesh
    • Kollam, Kerala, India
    • 10 March, 2009

    Thanks for the site. It is very useful and interesting.

    • df
    • Germany, Bawü, ma
    • 27 February, 2009

    Hi Mark! Very nice site! So many interesting things going on here ;) ! Hope u have some time to pick up some new stuff... soon... keep going on! best regards.

    • herb
    • Halifax, NS
    • 15 February, 2009

    after being out of school for 20 years, I now find myself back into the books, what my digitial instructor misses I have found here. Thanks for the wonderful site.

    • Dario
    • Canada
    • 6 February, 2009

    Thank you for this site!

    • rasheed k
    • India
    • 5 February, 2009

    i am really very happy to find this site.i am beginner in PIC programming.very very thanks to this site.

    • Damian
    • Australia
    • 26 January, 2009

    Love your DIY section keep up the great work. I love working with my hands but I need to see something visually before I am confident enough to tackle it.

    Your DIY garden shed was great. Not many garden sheds in Australia look like that it came up really well. Most of our garden sheds are made from steel and are prefabricated.

    Anyway keep up the great posts.

    • abhilash
    • India
    • 1 January, 2009


    • Mike
    • Savannah, Georgia, USA
    • 16 December, 2008

    I've had a pair of Rogers LS5/9 since 1986. I enjoyed your website and particularly your analysis of LS5/9. The only problem I've had with these speakers was with one tweeter voice coil that had a bad wire feed solder connection. I purchased replacement voice coils from a US church organ maker that used these tweeters in church installations. I didn't bother to acoustically balance the repaired tweeter, because I wouldn't hear the difference (old ears).

    Thanks for your efforts in creating this website.

    • John Lofthouse
    • at home in Dewsbury W Yorks
    • 22 November, 2008

    loads of interesting info looking forward to reading the projects

    • suzan
    • USA
    • 17 November, 2008

    dear mark, the first time i heard the sound from a pair of roger speakers i thought i had a new pair of ears put on. beautiful sound. that was many years ago and my ex-husband took the stereo and i would like to find out where to buy another set as well as a good system. thank you, suzan

    • Enahoro Olori
    • Port Harcourt, Nigeria
    • 30 October, 2008

    Hi Mark,

    Your website is most encourging as i explore the world of pics for my sinewave inverter applications.

    Best regards,

    • TrevorV
    • Kent, UK
    • 27 October, 2008

    Great site for me as a beginner of programming PIC's at the grand old age of 60!!
    Keep up the good work. Will check back often to se if there are any additions etc.

    • kamarul azman
    • Malaysia
    • 27 October, 2008

    your projects are nice. since this is the first time i read about your article it is very helpful. as a speaker box designer lately i experiment with arcylic material with minimum thichness 5mm with 4" driver and of course a 2 way system. may be we can change ideas later.

    • Jorge Toledo
    • Colombia
    • 8 September, 2008

    Thanks for your generosity with your knowledge, your explanation of Op-Amps inverting and non-inverting is great and superior to many boring books.
    Thanks a Lot!!!!

    • Joe Young
    • The foothills of the Pyreneese, Nr. Biaritz
    • 29 August, 2008

    What a pleasure, more, more, more. I'm building my first listening room and a pair of gainclones for the surround system, very helpful articles. Thanks, Joe.

    • Pierce
    • London
    • 25 August, 2008


    Just to say your intro to PIC for beginners is one of the best I've come across. Thanks and keep up the good work.

    Best regards

    • Sigfredo
    • In Spain Prov. Pontevedra
    • 8 August, 2008

    Dear Mark

    Thank you for your effort to teach other persons to learn things that are so very clear to you. I have teached telecommunications at various universities, in Buenos Aires and in Spain at Vigo, and have read a lot of bibliography in my life but I have never seen any publication explained so fantastic and so clear, with an exceptional didactic, as your document about PIC's.

    I appreciate especially your work oriented to help other people to understand technical and not easy matter like PIC's. I would like to congratulate you for your nice site and Thank you Mark very much!

    Sigfredo Pagel

    • Richard Jungert
    • Western USA
    • 24 July, 2008

    Nice work on all your projects. We appreciate good engineering and quality sound and Hi Fidelity.

    Keep up the good works.

    Richard Jungert

    • Amedeo Zauli
    • Italy
    • 14 July, 2008

    Very, very interesting site. Congratulations


    • yashwant
    • India
    • 2 July, 2008

    Thank you for website. "wish you all the best 4 future"

    • Pak Leng
    • Malaysia
    • 25 June, 2008

    I have the 3rd edition of A1, bought in 2002

    Just change new caps

    Did some modifications, bypass the preamp, but switchable to integrated.

    Something to share with you guys here

    I found A1 power amp sounds superb when using "transformer passive preamp". Amazing detail, clear vocals and tight bass

    Also, tested the modified A1 with DIY Audionote M7 preamp. This is the best combination for A1. Result is deeper bass, sweet vocals & good details.

    • James Hollingsworth
    • Las Vegas, Nevada
    • 8 June, 2008

    Best practical info I have run across. Microchip could stand to include some of your tutorial in their application guides. I think manufacturers feel compelled to bury useful information in proprietary vocabulary, formal syntax and notation, to impress their competitors. Thanks again.

    • Prakash Sidaraddi
    • India
    • 19 May, 2008

    Simple: I loved your work. Brilliant

    Thanks a lot...

    • Thanos
    • Berkshire, UK
    • 17 May, 2008

    Dear Mark,

    its amazing how truly educational your articles are...I came across your web site by chance and i stuck on it for hours literally sucking in all the information your offer...

    Its really amazing how simple you put things...every single sentence sinks in the first time...let alone all those things that i neglected all these years...

    I only wish you could turn this web site into a full time job. The world needs brilliant teachers like yourself...

    All the best!

    • Bill
    • Montreal CANADA
    • 22 April, 2008

    Your unit is very interesting...

    I'm looking to add remote controlled volume to my pre-amp. I also want balanced connections (which are basically 4 channels & your unit has 6 channels).


    • Jake Hughes
    • England, UK
    • 20 April, 2008

    I have to say, you have inspired me to build my own solid-state amplifier when I saw your GCSE project! I am amazed at how complex it is and how good it must sound! I'm 15 (but not doing a DT/CDT GCSE sadly) and I've always wanted to design my own integrated amp...but never had the know-how. If you could give me a few quick pointers I would be very greatful!

    I hope all your other projects are going well! I too love Rogers speakers (never was a ls3/5a fan though...not enough dynamics for me) and I too use Arcam products (current system is the Arcam FMJ A32 with Arcam CD73T and Wharfedale EVO2 30 speakers).

    Kind regards,

    Jake Hughes.

    • Wayne
    • Barnsley UK
    • 16 March, 2008

    Very clear cut stuff, i hope to see a book on this published.

    • Ross Williams
    • Cornwall
    • 3 March, 2008

    fantastic site, you really know how to explain things! never stop, please.

    • Darijo
    • Croatia
    • 19 February, 2008

    Greetings from Croatia!
    I love Rogers speakers,great and lovely midrange, informative and sweet highs,controled and powerfull bass! Soundstage in my room is excellent!
    I bought pair of Studio 1a,about few weeks ago, they are great upgrade in my hi-fi.

    My HI-FI:
    Arcam Alpha 7se - cd player
    Oakley Image - Tube preamp(hand made in Croatia)
    Rotel RB06 - power amp
    Rogers LS33
    Rogers Studio 1a
    Cardas 300B & Audioquest King Cobra - interconect cables
    Audioquest Pikes Peak(single Bi-wire)- speaker cable

    • Seth Lubin
    • Newark, New Jersey USA
    • 17 February, 2008

    I'm so glad I found your web site!

    For the longest time there seemed to be no information or comments about Rogers Studio 1. I have had them at least twenty five years.

    All the rest of my system has been upgraded, but the Rogers remain. They still give me great pleasure and as I have changed other equipment they always seem to sound better and better.

    I would be hard pressed to find such a warm and detailed speaker as the Studio 1s. I generally listen to all types of classical music and play vinyl. The soundstage and quality of voices and instruments seem so true to me.

    As we are farther and farther into the digital age; I tend to hear wonderfully detailed digital based speakers, but without warmth of tone.

    Someday they will have to be replaced, but it will be very difficult to find another speaker that can please me as much.

    Thank you for posting all the photos and reviews.

    • Peter Thomas
    • Australia
    • 9 February, 2008

    Nice work on this site. Like many others I'd been looking for a getting started with PIC programming, this stuff is great.



    • Nik Halton
    • Bucks, England
    • 21 January, 2008

    Just thought you might like to know that there is a pair of LS4As still going strong in Amersham! I got mine new from Sevenoaks Hifi in Cheltenham around 1990 and have loved them ever since.

    They were originally bashed around by me going to college and have now been bashed around by my children! They've been repaired and serviced by Tony in Sevenoaks at least once and still sound as good as ever.

    They started off as my stereo speakers and are now doing proud work as the front L+R of my surround sound setup!

    My father also still has a pair of LS4As, as well as a pair of the larger LS8As and I keep trying to talk him in to giving me the 8s!

    Thanks for a good site, pity there's so little info on these speakers, although dad probably still has his owner's manuals!

    • Ajay
    • UK
    • 20 January, 2008

    Excellent site

    I HAVE JUST RECENTLY become an enthusiast after searching DIY LS3/5A and read about GINI LS3/5A - I would like to know if any of the members have had any experiences regarding this kit which apparently is not marketed in the UK / Europe

    • Pete
    • UK
    • 18 January, 2008

    Thank you for sharing your thoughts and projects with us. The info on your gainclones has really helped me understand the building process.

    Brilliant site

    • Alex
    • Canada
    • 13 January, 2008

    Dear Dear Mark:

    Thank you very much for your wonderful website. I learn a lot from you. Keep up the great work!

    Best wishes to you and your family


    • Mark Homer
    • London, England
    • 26 December, 2007

    Hi Mark

    Just wanted to say thanks for your A1 section of this site - I changed all the electrolytic capacitors on my 1986 A1 and it's back on song! (Back in Black?!)I have sentimental attachment to this amp. - it was my work experiance gift whilst at Mordaunt-Short. Symptom was - very low volume on the right channel, clean but about 80% down. Caps. from RS Components, including 35V power supply caps (ref 127-802, not radial but axial so I had to extend the conections with tinned wire), a decent amount of heat sink compound and a good scrub down of the top Heat sinks and it feels like new!

    Best regards


    • Manfred
    • Germany
    • 7 November, 2007

    dear mark,

    i must say that you have a nice web site. most of all i like your artikle about the A4-Amp. it look very nice and i hope that my amp looks as good as yours when i'm done with it.

    keep up the good work!

    best regards

    manfred (Germany)

    • Peppe
    • IT
    • 28 October, 2007

    Lots of compliments for your site and for shared your projects. You're great. I hope you continue to update the site.

    Thanks a lot.

    • Thomas Tang
    • Singapore
    • 28 October, 2007

    Greetings from Singapore !

    I instantly fell in love with your site as we have many interest in common. Programming PICs / making amps / collecting old british loudspeakers. Your info on Rogers speakers are 2nd to none... infact the trick on putting the bass driver 180 deg put a smile on my face. I recently picked up a pair of Tannoy Mercury M20 ( translucent cone & gold tweeters )... there was some rubbing on loud low freq passages on one driver.. I inverted both the drivers and now they sound excellent !

    Keep up with the good work of sharing!

    Best Wishes

    • Mark Ratcliffe
    • Australia
    • 23 October, 2007

    Out of sight - thanks

    • Simon
    • 11 England, 2007

    Great advice. Owned same LS4a speakers for 17 years - thought they had finally given up with increasing distortion from one unit, but turned upside down as suggested and problem instantly solved!

    • Nigel
    • London, England
    • 29 September, 2007

    Mark, thanks for putting together such a detailed site for starting in programming PIC's. I have spent a year killing 12F975's and decided to actually start to learn how to program these things.

    Right now i have a 16F84A is sat in my K8048 PIC Programmer board. There are 4 LEDS happily counting up to 16 in binary - excellent.

    It easy to program some HEX on to a chip, but understanding the assembler code is something else. Your tutorial has helped me enormously in actually understanding the code.
    5 Stars, Thumbs Up, A++

    Thanks again

    • Tim Hodson
    • Amersham, UK
    • 28 September, 2007

    Really enjoyed your site! I work in IT, but my main interest is music and music technology, so I appreciate your particular perspective!

    All the best,

    • Stephen
    • New Zealand
    • 13 September, 2007

    Hi Mike
    This is a good site. I use to know all this stuff but then got sick and it's like my brain was was erased. So your site is providing me with lots of ideas and examples I can build to get my brain started again. Also it's a lot of fun


    • Jerry
    • Massachusetts
    • 29 August, 2007

    A very informative website. Seems to cover the basic information needed to work with PICs.

    • Christine Mickelson
    • USA, Sioux Falls South Dakota
    • 16 July, 2007

    Dear Mark,

    Thank you for creating this site. My significant other and I have been searching high and low for a begining to PIC programming and your site is just what we need.

    Highest Regards.


    • anthony
    • Glasgow
    • 3 July, 2007

    Greetings from Scotland!

    I really like your web site; most informative and ref. your home life, most reassuring. You are a great encouragement.

    Best wishes to you and yours.


    • zool
    • browsing through google
    • 18 June, 2007

    I am trying to learn the PIC the easy way, but none available in the internet, not until I found your website. It is clear and very concise.

    It's written with down to earth language, and very easy to understand. I am embarking on a cnc router project, and I need to know the way to program a PIC.

    You deserve a credit on this, and thank you very much for a splendid tutorials.

    I bookmarked your website, and looking forward for any updates.

    Thank You.

    • xbot sanchez
    • PH
    • 13 June, 2007

    thanks for the info mark. am also planning to build similar shop as yours so i can go ahead workin on some stuff.

    am also into arts, music and electronix... they all seem to fit together don ya tink?

    • jay douglas
    • Arizona, USA
    • 28 May, 2007

    thanks for your efforts. its a great site. the legend that is rogers, lives on.

    • Jimmy Tuffrey
    • Bristol
    • 19 May, 2007

    Oh 'Studio 1's' so that's the name of the speakers I learnt sound on. We had these when I worked at Wild Tracks in the late '80s. Always wondered what they were called. Should have taken more notice at the time. Will never forget the sound of them though. We had four pairs and even now I hear that sound in my head when using my inner ear. An old fashioned sound but very pleasing. Remember them like yesterday. Nice one for your Site.

    • Richard Harris
    • UK
    • 11 May, 2007

    Nice conversion - Sadly my good lady seems to think we should keep the cars in our double 24 foot wide garage :-(

    If you not aware of them have a look at as an alternative to Parallax. UK company and cheaper.

    I came by your site as a result of your battery monitor being Blogged on We are building an electric car (Greenpower racing) at school and have got to the instrumentation stage, better condition was one of the must have features

    • Pat
    • London
    • 8 May, 2007

    Just found your site when looking for links to Orchid White paint. I'm into hi-fi too, and have some MF stuff, a Pink Triangle turntable and a 1970s bathroom suite also in pink!

    Will come back for a proper look tomorrow...

    • Jeremy Travis Teletape
    • London
    • 5 May, 2007

    Thank you for your great site. I worked in the Hi-Fi trade for twenty five years. My company produced the legendary JR149 loudspeakers.

    I retrained in production engineering but ended up working in a school. Having now lost my job I have returned to my roots and want to build my own system again. I used to know John Linsley Hood and of course Jim Rogers.

    I will enjoy looking at your site. I hope I will find some good designs I can make myself and get back to real music.

    MP3 sucks - Hi Fi forever

    Thank you

    • Ray Evans
    • Bolsover
    • 24 April, 2007

    Thank you for your site..just starting with assembler and pics. Thank goodness for a clear and easy to understand tutorial.

    • FADY
    • Israel
    • 19 April, 2007

    thank you a lot for these important information about pic

    • Howard Bailey
    • Bournemouth in Dorset County UK
    • 16 April, 2007

    Dear Mark,
    I 'stumbled' across your site whilst browsing, it's definately bookmarked now.
    I like your method of teaching, it's very good, especially for complete newbies like me !! Please, please, please more of the same. There is a saying in a UK TV advert i.e. "Those who can, TEACH". I teach First Aid & advanced First Aid, so I understand a lot of the prerequisites that make for good teaching and the satisfaction that you get from it.
    Working on my own I am finding it hard and slow going, where would you suggest would be the best places to study/meet others/courses, to accelerate my learning process ?

    • Christian Furész
    • EU, Hungary
    • 26 March, 2007

    Great site!
    I'm not so good at English, but I can understand what you wrote. My favourite project from yours is the 'A4 power amp'. Where can I buy a button like that?
    Congratulations from your A4.

    • ganesh kumar
    • India
    • 18 March, 2007

    hi Mark,
    Thanks for your kind effort to prepare and share such a wonderful work. Yours is one of the best tutorial I have ever come across. Keep going and Growing.

    Thanks & Regards,
    Ganesh Kumar.

    • uzun
    • Türkiye
    • 2 March, 2007

    Great info for me.Has helped me understand PIC programming. Thanks for share.

    • Antonio
    • Mexico
    • 22 February, 2007

    Saludos from Mexico!

    Very clear instructions on Pic programing.
    I'm taking a colege course on microcontrollers, but my teacher was always a big A*s >_<
    Your site helped me understand the basics, now I'm on my own and I'm doing fine! Thanks alot!

    • Oliver Roditi
    • Glasgow, Scotland
    • 22 February, 2007

    Would like to congratulate you on the amazing site. I'm currently sitting with an A100 in front of me and am utterly astounded, such an informative site with a great design. Haven't found much like this for a long time.

    • Caros Chean
    • Brazil
    • 18 February, 2007

    Wow, I was impressed with your work! As a Musical Fidelity enthusiast, I own 2 A-1, a "British Fidelity" labeled american model and a mkIII version. I also own a P140 power amp and a Digilog DAC. I hope to get a Collector's Edition someday. Please keep with the good job!

    • Frank
    • Germany, Baden-Württemberg
    • 27 January, 2007

    I am really impressed about your exact work and dokumentation. Go ahead with it.

    • B. Fisher
    • Welland, Ontario, Canada
    • 18 January, 2007

    Google searched on "Rogers Studio 2 speakers" and came across this great site-kudos to Mark! Am asking anybody out there if they have any info/critiques on these Rogers. Thanx again Mark.

    • Kyle
    • Chicago, Illinois - USA
    • 16 January, 2007

    Just wanted to say thank you! Your PIC tutorial was very straight forward and easy to learn from.

    • Andrew
    • Tokyo, Japan
    • 14 January, 2007

    Great site Mark - I hope you are working in a development environment somewhere turning out great products! Nice clean design (I'm talking about your pre-amp here) and beautifully executed.

    Best wishes

    • Jared
    • Brisbane
    • 3 January, 2007

    Hi Mark,

    Great website - Great Info.

    Has helped me understand asm programming - Finally!

    Congratulations on the baby.


    • Navajyoti Saikia
    • Namrup-Assam-India
    • 26 December, 2006

    just stumbled into your site via google. great job for learners. looking forward for the future enhancements. please don't remove anything from this site. they will help many around the world. keep it up.

    • Julian
    • Wales, UK
    • 26 December, 2006

    Hi Mark,

    I am just starting out PIC Programming for a small project that I would like to get sorted out and came across your site by accident on the web.

    I must say that I am impressed.

    I was just wondering if you might be a Radio Amateur by the content of parts of your workshop ?
    I used to be in the electronics repair trade but don't do much of it these days however the PIC project is revitalising my enthusiasm for this kind of thing

    Best Regards

    Julian Cleak ( GW4JBQ )

    • Nico
    • Amanzimtoti, South Africa
    • 10 December, 2006

    I followed a comment on diyAudio. I must commend you on placing so much attention to detail in the little project. If it sounds good there is no harm in making it look good as well.

    • balto the wolfdog
    • England UK
    • 5 December, 2006

    Great site, very informative. Interesting, as I have purchased a Musical Fidelity A100 amplifier, with the intention of refurbishing it as a project. Currently, I am having a problem with the selector switch, and would like to obtain a replacement. Thanks for the circuit descriptions.



    • Charles
    • Portugal
    • 28 November, 2006


    congratulations it's great site all is very well explained and we can easy understand
    perfect work



    • Ben Louw
    • Singapore
    • 28 November, 2006

    I enjoy visiting your site. I bought a pair of LS2a/2s in 1996 and they still give me great listening pleasure.

    • Adam Boardman
    • Buffalo, NY USA
    • 13 November, 2006

    I own what I was told are the last pair of LS8as - and, therefore, probably the last pair of speakers - the "original" Rogers ever made. They're in great shape, I love 'em, and it's good to see through your site that should they ever break, their ought to be in good, if few hands.

    • James
    • Virginia, USA
    • 17 October, 2006

    Great site, I found more than I was looking for

    • Michael Menina
    • Laguna, Philippines
    • 14 October, 2006

    Great Site!!!Nicely done. Now I have something to pattern with my next amp and preamp projects.

    • Walter
    • UK
    • 10 October, 2006

    Like it

    • Anh Tuan
    • Vietnam
    • 5 October, 2006

    It is very usefull for me.

    • Charles McCrimmon
    • Scotland
    • 5 October, 2006

    Nice clean website,

    Loved your DIY workshop, found yer website while looking for some inspiration on designing my own hobby area. Was helpful to see how someone else approached it. Also nice to find some PIC resources here, just got myself a programmer but havnt spent any time with it as yet. Waiting on completion of my area to work in.

    • Gufran shaikh
    • 5 October, 2006


    • Bob Durk
    • Ontario, Canada
    • 17 September, 2006

    Hello Mark,
    I just stumbled across your site and admire the professional set-up and layout.Very nice to navigate as well.I think the main reason I like the site is that I was on it for less than 5 minutes and already found helpfull info. This will help a "Mainly Self Taught" person program in a more logical fashion.
    Thankyou for the resourse and I am looking forward to returning to the site (hopefully this evening!!)


    • Howard
    • Surrey, England
    • 2 September, 2006


    I did enjoy your articles on Rogers loudspeakers. I have a pair of Rogers LS7s, bought in 1983, and I have not yet felt any need to upgrade or replace them, they are fabulous and still work perfectly. I found your Service and Spares page useful too, as I guess one day they may need repair.


    • greg angst
    • Houston, Texas
    • 4 August, 2006

    Mark, I like your project which uses four LM4780 chip amps. I am considering building one using 6 LM4780's.

    • Mark Lawrence
    • Taunton, UK
    • 2 August, 2006

    Nice to see a easy to read site keep up the good work

    • Matthew
    • New Zealand
    • 22 July, 2006

    I came accross your site while looking for a pre-amp design. After much browsing and reading, I have to say this is one of the best resources I have ever come accross!

    • Eddie le Roux
    • South Africa a small town called Welkom<
    • 13 July, 2006

    Found your site on Google - this is exactly what I was looking for. Thank you for a super range of articles and links.

    Keep it up. Well done.

    • Tyrmorr
    • UK
    • 10 July, 2006

    I have had my LS7's since I was a teenager, bought them second hand quite cheap.

    I never really realised what I had till just recently.

    Your site is excellent, well laid out, with a huge mass of useful information.

    • Jonney
    • Northern Ireland
    • 10 July, 2006

    Mark! What can I say? You have excelled yourself, this site is just what I have wanted for about 10 years, since I stupidly sold my pair of ls7's. I haven't fully explored the site yet and am being forcably removed from the computer by the wife, but will return as soon as I can and continue. Thank you!

    • John
    • England
    • 20 June, 2006

    Hi, I discovered your site by accident on google and it is exactly what I have been searching for, for years. Thank you very much.


    • Tony Wood
    • Darlington, UK
    • 9 June, 2006

    Congratulations on a beautifully presented site! And thanks for the PIC stuff which I found especially helpful and easy to understand.


    • Niko
    • Finland
    • 1 June, 2006

    Absolute great site!

    I love your Micro-amp & A4 Power amp -designs. They are just way too cool.
    Thanks of inspiration to start building my own LM4780-amplifier. I pass the link when it's ready. :)
    Also your workshop is perfect.

    • Richard Yim
    • Hong Kong
    • 27 May, 2006


    Well presented and well updated projects! Excellent introductions with some insights for every reader!

    As a fan of ROGERS LS3/5As, I feel particularly thankful for your efforts. THANKS indeed!

    Kind regards,

    • Dennis Baldwin
    • East Grinstead West Sussex
    • 17 May, 2006

    Hi Mark.

    You have a very interesting and informative web site.

    I found it as I was looking at LS3/5As on Ebay. I became interested in them after listening to my father-in-law's and him telling me about them and the history of the BBC's monitors speakers. He has a vast knowledge as he is the original “Golden Ears” a name he was given very early on in his thirty year plus career in the BBC.


    • Salim H.K
    • Oman
    • 17 May, 2006

    I highly appreicate your Contribution to free learning, please keep it up.

    • Mike
    • Australia
    • 6 May, 2006

    Hi Mark,

    I think your site is really great!

    I found this site when i was looking for information on pics, and liked the site so much i read nearly everything else too! I think the pic pages are very well done, although i cant wait until you finish the applications part.

    Good Luck


    • Alex
    • Russia, Rostov
    • 10 April, 2006

    Good project A4 power amp, good luck in new projects!

    • Jonathan Roozing
    • Veenendaal, The Netherlands
    • 7 April, 2006

    Hi Mark,

    i'm reading your pic programming pages, very helpfull for a pic-noob like me. Thank u very much for your efforts.

    Kind regards, Jonathan Roozing

    • Kim
    • Waterloo, Canada
    • 30 March, 2006

    Well done!!!!!

    Keep up the good work.


    • Pradeep
    • India
    • 27 March, 2006

    Hi Mark!!

    Your works are nice!!:-) Your photographs of your home were outstanding!! I liked them!! Nice work, you're really creative!!

    I have a Lab too equipped with some good DSO's and soldering stations!!

    Your site was a good uplifter!! It had many basic fundamentals!!

    Can I know when the PIC setion will open up!!

    Have a nice day :-)

    Thanks and Regards,
    Design Engineer

    • Sergio
    • Italy
    • 24 March, 2006

    Hi, your site is class A SITE!!!

    I picked up many information to enjoi my A1 in full rate. Only one thing..... my A1 is 1990 edition with holes in the lateral shield but I have no prolem with the Alps pot. Anyway, I made an upgrade with a motorized alps pot and I added a circuit in order to change the volume with a remote control. The value of the pot is the same and naturally the sound too. I think that the pot on the reaction on the opa is a good solution, maybe not the optimum for the noise :-)). The capacitor are all changed but I have not eard sound improovment. It's true we start from a good start...

    SOMEONE CAN TELL ME IF IT IS DANGEROUS TO CONNECT 4 OHM SPEAKERS (dynaudio audience 52) ON THE A1??? It's a week I'm doing and it seems works good... but a long term???? Thanking in advance.


    • Steve Brown
    • Flintshire Wales
    • 20 March, 2006

    Great site the best i have come across. The audax monitors look superb. A few years ago i entered a competion in HIFI CHOICE to design a speaker it was run in conjunction with CYRUS

    I designed a mini monitor made from birch ply and although
    i did not win I was invited down to cyrus for a tour of the
    factory.Sadly I could not go as i was on holiday.

    Mark how about a revamped jpw mini monitor?


    • Francisco Javier Olvera
    • Puebla, Mexico
    • 16 March, 2006

    Great site! Your Pic tutorial is one of the best explained tutorial I have seen. I am waiting for your applications future section...


    • Derek Rogers
    • London
    • 16 March, 2006

    Hi just a quick comment! It`s 3.25 am and my daughter sent the link to your site.

    I am one of the two sons of Jim Rogers who created the first Beeb loudspeakers and went on to produce his own Jr149`s and many others!

    Just skimmed through quickly but I shall return!

    Are a fan of dad`s amplifiers as well?


    Derek Rogers

    • Darrin
    • Australia
    • 11 March, 2006

    Your site is first-class, as is your design and workmanship, i am totally in awe of your talent.


    • Roland Doucette
    • Gilbert, AZ
    • 11 March, 2006

    I too share your joy of the ultimate sounding and greatest engineered speakers ever owned. I purchased a pair of RSL Studio Monitors from their store in Conoga Park Ca. in the early 80s. The speakers were assembled right in the back of the store. I was sooo impressed when the sales person gave me a tour.

    Anyways, they could be turned up VERY LOUD (like I did on occasions) and they NEVER failed me. The speakers had just recently been unplugged and put in storage, until I figured how to configure them into my garage. BUT alas my wife put them out for a garage sale and asked a whopping 5.00 for them and they were sold....I still cry at night

    • David Payne
    • Clanfield Oxfordshire
    • 20 February, 2006

    I very much enjoyed reading the info on Rogers speakers. I have used a pair of what I think were Ravensbrook bookshelf speakers I bought in 1970 until a few weeks ago when one of the base drivers "went". So a decided to replace them. These had 8 inch base drivers and twin tweeters as way back then if a loudspeaker enclosure had three or more drivers in it was purchase tax free(this loophole did not last long.) They are now retired to our spare room but I can't keep them there too long. If you know anybody who would like them as spares drop me an email. Somewhere I may also have a Ravensbrook amp with one switch button missing probably swallowed by a hungry daughter so beware!

    Cheers David Payne

    • Scott James Bartlett
    • Oxford, UK
    • 22 February, 2006

    Hi Mark,
    I recentley joined a copmuter firm in the workshop. As you can imagine lots of nice toys to play with. Anyway. I had never built or soldered amnything and decided to have ago. 1 year many velleman kits later, I wanted to build an amp for my PC. I used 2 LM3876 IC's from the overture series and it worked first time. Yippee!! The sound impressed as well. I did this without any online info and since looking at the "gainclone" sites I made a very sloppy job <including a very dodgy headphone socket circuit using a relay with 8ohm 50watt power resisters as a dummy load>. So I'm going to try again.
    Your site is the best I've seen and would like to thank you for taking the time to help others.
    I'm thinking of using 2 LM4780's for a power amp, what say you? <remember I'm just a fledgling>

    • Lee
    • Kent
    • 21 February, 2006

    Just been browsing for info on insulating workshop floor and found your site. brilliant ideas and photo's more informative than some books. i will be back for more tips in the future, keep up the good work. Lee

    • Mike Restall
    • South London
    • 17 February, 2006

    Thanks for the tip on turning the cabinet over to test for a sagging bass driver.

    I found a pair of LS7t's abandoned on the street yesterday.

    Dragged them home full of hope only to find one of them popping and clicking away when I hooked them up.
    Dishearted I began to trawl the net for any sign of a replacement. You can guess the rest.....

    Thanks again. They sound lovely!

    • Gunther
    • Belgium
    • 8 February, 2006

    Nice things you have over there, I really want to be able to build those myself too, robably within 10 years or something like that ;). I've also noticed your new family member, cool, he is born on the same day as I am :p

    • Lars Willeboordse
    • The Netherlands
    • 6 February, 2006

    Just wanna congralute you and your wife with your new baby boy.!! he looks gorgeous:)

    Thanks for the site also because i use it all the time as a reference for my own projects

    Kind greetings Lars Willeboordse

    p.s. i would love to see pic-section expand;)

    • Pedro Martins
    • Portugal
    • 3 February, 2006


    You have now a kid to care! I have mine on the way!... Next June he will be with us! That makes more two audio/electronics fanatics!


    • D. Luijten
    • Den Haag, Netherlands
    • 7 January, 2006

    Hi, I found your site a while ago already and am planning to revise my A1-X the same way. Thnx for the tips and instructions.

    and Byron: try the Eagle PCB design software. It is free and is working quite well. I use it at my university too.


    • Byron
    • South Africa
    • 3 January, 2006

    Hi Mark!

    I thought I'd let you know that I've found your pre-amp project supremely inspiring. I stumbled on your site while trawling for ideas on how to design a multi-channel pre-amp and suffice it to say your use of a PIC Microcontroller and digital peripherals has given me a good idea of where to go. My biggest issue is practical and easy to use PCB software. There are so many offerings, but none of them seem to be ideally suited to the DIY user.

    Anyway, thanks for posting your experiences and keep it up!

    • Pravardhan
    • Bangalore, India
    • 25 December, 2005

    Well, I liked ur home page & ur works are clean & neat. I read ur articles & they are very good!


    • Alfredo Gaggero
    • Uruguay
    • 22 December, 2005

    Really a fine place ,with a handful of information about pics and other stuff. Well done folk!

    • Simon Jones
    • London
    • 19 December, 2005

    Lovely site! Came here on a search for "dual tracking bench psu" and ended up browsing for ages! I'm just reviving my long dormant electronics hobby and obviously a decent PSU is the first thing I need... I'll probably nick some of your ideas if yoy don't mind.

    Got lucky with a scope... found a Tek 465B on the street next to some rubbish bins. After letting it dry out from the rain and reseating some of the socketed transistors in the timebase section it seems to work fine!

    Love the Audax monitors, they really do look gorgeous.


    • joao cardoso
    • Portugal
    • 14 December, 2005

    Looking for PIC chips i found your site. It is a great site with a lot of good explanations.

    • Peter Mulholland
    • Norwich, UK
    • 13 December, 2005

    Good to see you're finally settled in your new place. Having moved twice fairly recently I know what hell it is. I'm glad you made it through OK.

    Looking forward to some new stuff to read about from you soon :)

    • Stew
    • Alberta, Canada
    • 7 December, 2005

    Well, I've lurked onto your pages before, and have seen your handiwork as well as others, via

    I must say that my DIY efforts pale by comparison, but at least we have the same taste in books (Is that Horowitz and Hill on your bookcase?). Nicely constructed, without a bunch of "audiophile" type discussion. I could be classified as an "audiophile", but there is SO much pretension built into that label. I've been a proponent of good doesn't = expensive (all the time). There are some true bargains out there if one wants to have fun and enjoy music rather than equipment.

    I find that simplicity in design and execution is what we should all strive for (the "Zen" thing if you will). Might I add a minor criticism? An extended listening impression or conclusions area would be nice and of course comments of use with different loudspeaker types if possible. Nice page, and very straight forward without any "flash", again good basic design. Thank you for your contribution to truly good content on the Internet, and specifically the clarity of language and the restricted use of "flowery" language. :-)


    • Kris Dissanayake
    • Sri-Lanka
    • 2 December, 2005

    easy now! superb design. specialy well organized!!

    i'm curretly learning pic programming!
    thinking of making digital controled sound processors for uk market! ST ics will be used! i hope i could reach my goal one day!

    keep up with your works mate!

    • Matt Meyer
    • Los Angeles
    • 26 November, 2005

    So I purchased a set of Rogers Studio1's back in 1988 w.o realizing what I had. I've loved them.

    But now, with all the new technology and wonderful speakers out there, I am thinking of upgrading my home theatre. The question for you folks is -- would you replace the Rogers (No, I am NOT selling them!) and if so, with what?


    • Naresh
    • India
    • 22 November, 2005

    About your website -Inspiring and Innovative !

    • James Power
    • Ireland
    • 4 November, 2005

    Well done.
    A very well put togeather site good simple information about a subject which can be very complex.
    Look forward to useing the site in future.

    • Todd J
    • Vancouver, Canada
    • 25 October, 2005

    Great DIY information. Very insightful and informative. Thanks a million!

    • Vikash
    • Dunstable
    • 14 October, 2005

    Ello mate, just checking in to see what you've been up to recently. I was quite proud of my P2P LM3886 till I saw your LM4870. Grrr. ;)

    As always, I'm leaving inspired...

    • Alex
    • 13 October, 2005

    Good site, very nice project pre amp.

    • Helen Holt
    • Surrey, England
    • 9 October, 2005

    Excellent site. Been looking on Ebay for speakers to replace my existing ones, and had been getting very frustrated with trying to find reviews of some of them. Been thinking of trying to get some Rogers speakers for a while..great to find such useful info. At present am using some prototype Tannoy speakers (dont think they actually went into production) with my homemade (not by me!) triode amp and currently using the phono stage of a Marantz midst of building a tube one myself.

    • Dave
    • Argyll
    • 8 October, 2005

    Your garage conversion project has given me great ideas for mine - and enthusiasm too! Many thanks.

    • Steve
    • England
    • 4 October, 2005

    This is a good site best I have seen. I know jack about the PIC but it is helping and going in, in dribs and drabs.



    • Gilbert W K Lau
    • Hong Kong
    • 2 October, 2005

    Dear Mark,

    Thanks for the articles, the site. I really learn a lot from here. I also have a MF A200 Signature, which was my first Amplifier back to more than 18 years. I still keep it as one of my collection as an invaluable item. I keep it clean & tidy as a respect it this fine product. It is my good company ever.

    I appreciated your view in article regarding ATC20SL, because I am going to buy this product from Audiogon. & I hope I will keep it after 8years of time, like your good friend Richard. Changing Hi Fi gear or you may say "Buying & selling Hi Fi products" is my ONLY hobby. I should say searching for SOUND EXCELLANCE is not a simple game. You need to make a lot physical test by serious audition for all of them, before you can make fair & honest comments.

    I did not have knowledge about ELECTRONIC ENGINEERING, like you. So I try them physically to have the test result by hearing & trying different combination of different items to look for sound quality improvements.

    I really appreciated your effort in making this site for those guys they love or like Hi Fi. Without your effort, we will not for sure have such a good view about those items.

    Looking forward to having more article from your end. Thanks a lot.

    Warmest Regards

    Gilbert Lau

    • Richard Senn
    • London, UK
    • 28 September, 2005

    Excellent site, very informative, superb info that doesn't exist elsewhere.
    Keep up the good work.

    • greg mitchell
    • Surrey
    • 12 September, 2005

    Great site Mark,

    Just revisited the world of Musical Fidelity with the A100 amp. I used to have an A1 back in the 80's and had forgotten how good they were and still are!. So far my LP12/Lingo/Ekos/Arkiv and my Roksan Xerxes/SME V/AT-OC9 have had me smiling, both running through A100's phono stage which, imho, puts many outboard phono stages to shame, I kid ye not!

    Just got the nerve up to open her up and low and behold half a tonne of dust (glad I did read through your site otherwise would not have known about heat sink compound!!)

    Now looks as good as new and thankfully both fans are spinning freely without dodgy bearing noise - yes the fans are going to make a noise but so what? turn the amp up a notch and just forget it.......before you know it its 7.00am, break a couple of eggs and some bacon on the heat sink and keep on smiling.

    • Alan Parekh
    • Canada
    • 11 September, 2005

    Nice projects, I like the battery monitor...


    • Jan Rasmussen
    • Denmark
    • 29 August, 2005

    Nice page Mark.
    Like the layout and content :)


    • Brett
    • Brisbane, Australia
    • 27 August, 2005

    I love the work you have done.

    I am 13 and always looking for somthing new to do i save the projects into word so i could print them out a school.

    keep up the great work


    • Tony
    • Crawley, Sussex
    • 25 August, 2005

    I have been into hifi since is was 13 and have gone through numerous setup including a thorens michell hydro referance rotel, and a & r amps to cd players os various dubious quality but because vinyl became hard to get Doh! ??

    so one day im looking in a dodgy seconhand shop window and saw a pair of rogers studio ones on rogers stands these were the stuff of dreams when i was 17-22 so parting with 125 quid i took them home polished out the scratches goodbye mordaunt short ms25i pearls wow i had a pair of sony apm22es which klled everthing around but these ageing rockers blew them away the control was unbelivable ive now gone full circle managed to get a vellerman 4040 4 kt88 driven valve amp 45 wpc pure class a reengineered by an old GEC chap who built it this is fed by a denon 1905 for just the main left and right its a digital 7.1 job but very good a nakamichi av10 bridged powers a wharfdale 12" sub

    the pride and joy is a systemdek ii ex with a linn basik and goldring gx1012 which i prised out of a sellers hand for 150 quid when i was a teenager this lot would have cost a years salary now i can fully apprecaite the quality of sound that went into vinyl. the rogers are too clinical for ordinary CD the amp does soften sound a little but produces around 40 amps thats a lot of punch watts dont matter with valves. DVD audio and SACD are ok but vinyl is king rogers deserve vinyl and valves

    • Boris
    • 1 August, 2005

    You are the best...

    I did it...New A1...with separated PSU, loudspeaker protection, Alps, WBT, Cardas, good capacitors...

    Fantastic smooth sound, a lot of temperature and that's it...

    Best regards and all the best

    Thank you for all your support


    • Michel BOIMARE
    • France
    • 23 July, 2005

    Thank you for this pretty job and explanations (as usual !).
    I just received two LM4780 samples from NS. I know how I will do now !

    • Tim Gasser
    • Oxford, England
    • 13 July, 2005

    Excellent website ! There are some great projects on here.

    • Peter Garmidolov
    • Bulgaria
    • 15 June, 2005

    Excellent learning materials for PIC programming for a beginner like me.

    • Justin Stapleton
    • Bedford, England
    • 13 June, 2005

    Great site. Just bought an A1 for £49. It has noisy volume and selector pots. Seems a common problem. Having been engrossed in your site for the last 30 mins I mat well bone up on electronics !!!

    • Nick
    • Bedfordshire-England
    • 1 June, 2005

    Excellent site-thanks

    • Morten
    • Sorø, Denmark
    • 25 May, 2005

    Great site. Very informative. I read and learn a lot about programing the PIC16F84

    I hobe you vill make more pages.

    God side. Meget informativ. Jeg har læst og lært meget om programering af PIC16F84

    Great work and keep it up.
    Cheers, Morten.

    • Bernard
    • California, USA
    • 17 May, 2005

    Great site. Very informative. I just acquired a pair of Rogers LS6 and I am blown away by them. I am using them as monitors for my home studio. They seem to be extremely true and it is amazing how much bottom you get from these, they are light in weight. The black cylinder that fits into the bass port had come loose. I put them back in place. The side that is in the speaker I put the cut away side face up. I think that is right. Do you know for sure? Thanks. Keep up the great work. Bernard

    • Michael Perini
    • Bucks County, Pennsylvania USA (near Philadelphia)
    • 9 May, 2005

    Love the site, You obviously put a great deal of work into it, Thank You.

    I am a retired financial services exec. who has the luxury of developing just enough knowledge to be dangerous in a number of topics. My son David is a recording engineer and producer who is begining to develop some substantial credits (Maria Cary, Luthor Vandros, Pat Metheny, original cast album Hairspray). He worked for several years at one of New York's largest recording studios-Right Track Recording where he had access to the finest equipment, - their newest 5.1 control room had Soffet mounted Genelec mains that cost over $250k US. So when he went out on his own he had golden ears with an aluninum budget. Therefore he setteled on the obligatory Yamaha ns10's for nearfields Tannoy 12" Dual Concentrics for mids.

    On a lark one day I pulled out my 20 year old Rogers Studio 1's -- and everyone was BLOWN AWAY . He used them for several months ( always at reasonable levels) and one day one speaker was dead. No sound at all. We've been looking in vain for a repair facility who knew the speakers to no avail. Afraid to trust them to somone who might repair them but change their voice.

    So they've been idle for a year. The NS 10's have been replaced /augmented by a new pair of Genelec 8050's at $2000 US each. They are spectacular nearfields but a bit clinical (as they should be) when compared to our memory of the Rogers. It seems to us the combination of the Rogers & Genelecs would yield Spectacular Mixes.

    • Goran Poprzen
    • Calgary, Canada (close to North Pole :)
    • 22 April, 2005

    Hi, Mark
    I found your site very informative. Lots of good links, too. Well, we bought a house two months ago and right now I'm in the process of planning how to setup my little electronic hobby workshop in the basement. If you don't mind, I would like to use some ideas from your DIY/workshop pages.


    • John Boyles
    • Oxford, England
    • 15 April, 2005

    bought rogers ravensbourne when it appeared,it was a very good amp in its day. the variable slope filter was very useful for taking out background hiss on vinyl and would still be useful on amplifiers today i remember it worked very well with celestion ditton 15's a good alternative to rogers speakers are the older spendors(bc1) or harbeths all built to bbc specifications

    • Robert
    • Melbourne, Australia
    • 7 April, 2005

    Hi Mark,

    I have only recently become aware of your website after acquiring a pair of Musical Fidelity ma50's. One of which needs a mains transformer replaced. I am told by the local repair people (recommended by the distributors here for Mus.Fidelity products) that they cannot trace one here. They have also said that they are trying the UK but don't know whether they can source one there either. I have'nt even got to listen to them at home yet!! I wonder if you have come across this before? I imagine I could have an external transformer fitted to each if it goes that way with the supply of these parts.

    But back to your fine efforts as a web host! This is a very impressive site with more information on the featured items that the manufacturers would ever include or be bothered to tell us. Your passion is evident in bundles.

    Great work and keep it up.

    • Stewart Emmings
    • England
    • 5 April, 2005

    Hi There;

    Most informative - as an owner of 2 original pairs of LS 5/8 loudspeakers with AM 8/16 amplifiers I learned much of some of the problems I myself am experiencing with the units as they age although it has to be said my main pair function perfectly. Many thanks for the detail on the Quad 405's!

    • Paul Toye
    • Brighton, UK
    • 1 April, 2005

    Hi Mark, I've found your site very informative, especially the Rogers section. I have run a pair of LS7t's for years with an Audiolab CD & Cyrus Amp/PSX and think they are just brilliant. I recently went "AV", bought a monster Rotel processor/amp and have considered changing the speakers for a surround package. Everything I've heard so far is simply nasty (PMC, KEF, etc), hence I'm trying to find a centre speaker that has a similar tonal balance to the good old LS7t's. Has anyone contacted you with any possible suggestions (except for another LS7t as I don't want that big bass driver magnet anywhere near the TV screen!). Many thanks for the good reading, Paul

    • T.Q.Choudhury
    • Dhaka, Bangladesh
    • 1 April, 2005

    Dear Mark,
    At the risk of looking overjoyed, this is one of THE BEST site I have seen. Logical and very informative.
    A beginner that I am, I am still groping at the File adressess. To be precise suppose that I want to declare any variable say Count, is it only the GP registers that I can use? i.e Count equ 0Ch, or 0Dh etc. In some places I have seen declaration like: Count equ 08h.
    Perhaps you couls add a few para on variable declaration to make your tutorial more complete

    • Jonathan Darker
    • South Africa
    • 12 March, 2005

    What a supprise!!! Nice treat....

    I am looking for reviews on Musical Fidelity "The Preamp" , "Typhoon Power amp" and "Tempest Integrated Amp" as well as the MF CD2 review and specs... I am the proud owner of all of these products but never recieved any manuals as i bought the components 2nd hand...

    • Tomy
    • Indonesia
    • 3 March, 2005

    Good Site

    • Dave
    • U.S.
    • 3 March, 2005

    Mark, you have put together an excellent tutorial on PIC micros. I have downloaded the suggested applications and intend to build the programmer from the schematic you featured. I am also interested in interrupts as another reader is, and also A to D conversion.

    • Paul MacLeod
    • Bristol, UK
    • 28 February, 2005

    Fantastic. I learnt more over my lunch break than I did all weekend. Just one thing, 'Interrupts'.
    Ah, well. I'll just have to keep searching.

    Thanks very much,


    • Burhan ISIK
    • Turkey/Istanbul
    • 14 February, 2005

    Dear Mark;
    Thank you for the lots of valuable informations about PIC programming. I have found it excellent for the beginners of PIC programming. I am looking forward to seeing the completed part of APPLICATIONS SECTION. I would like to do more than LED switching.!

    Thanks again.

    • eric wardle
    • Woking
    • 11 February, 2005

    I have just unwrapped one of a pair of rogers bbc monitors (export) that have been stored in my wardrobe for 20 years !!

    The pair were bought from new around 1972 from chew and osbourne in essex.

    Using a CD test disk with Cyrus Quattro + Cyrus Q power amp (50watts) revealed a good base, mid range a bit scratchy, and super treble fine.

    After around half an hours run, things improved and it sounded very respectable- and that's running just one speaker

    I am so impressed that I am contemplating tidying them both up (internal wiring very thin, outlet sockets replace with proper screw terminals ) providing the wife can be persauded to have them back in the lounge (luckily they are in good shape, teak with a black/gold material on the front).

    thanks for the potted history of the rogers.

    Eric Wardle

    • andy patel
    • UK
    • 3 February, 2005

    Stumbled on your website by accident. Great Rogers section. The info on your website is clear, concise, without padding !

    I have been using Rogers and Quad from the begining (Cadet 3 and Ravensbourne amps, though feel sorry to have disposed of them then. Quad 33/303 and 34/306 still in use today). Always had Rogers speakers from the begining because of their sound. Wonder if anyone remembers their Wafer speakers. Have been using Studio 1a for the last 12ish years, without any problems, apart from cabinet re-finishing with teak oil. They sound best standing on bags of sand (aesthetically concealed of course) in fact any 'dead' ganular material like bags of salt used in water-softner, or 10 KG bags of grain etc.

    • Rusty
    • UK
    • 27 January, 2005

    Excellent site. Keep working on the applications I need all the help I can get!

    • Rob Heijnen
    • Netherlands
    • 26 January, 2005

    At last i found some information about my loudspeakers, and i like your site very much.
    Please go on with your site, i will meet this site a lot more now i know it. And i will put it to my favorits.
    Thanks Mark, regards Rob

    • jean claude fourriere
    • France
    • 23 January, 2005

    HI !

    I just read about ROGERS on Internet I was the french importer of ROGERS products from 1973 to 1978 or 79, I don't remenber exactly, with the company I create for this products, VALOIS DISTRIBUTION !< /br>Th "Revue du Son" gave very good tests about LS3/5 and Rogers BBC MOnitor at this time. I made also DECCA inclosures with there ribbon tweeter, and also an home made audio reference. My company stopped in 1986, and I restart in 1988, by building large cold plasma speaker called Tolteque AHL, and electrostatic game with the same name.At this time, I try to sell improvement about electrostatic loudspeaker for efficiency, bandwith,reliability, in USA. Thank you again for the interest about ROGERS. Jim Rogers was a good man, and I like his large ribbon midrange/tweeter he made at home
    Yours sincerely


    • Ken Owens
    • Addlestone in Surrey UK
    • 21 January, 2005

    Brilliant site Mark, can't wait get hold of an A1 to mess about with. Using a couple of home built EL34 PP monoblocks at the present time. I have quite a lot of Sony gear as I used to work there as a bench audio engineer (we could get it cheap graded stock). Surprised you did not like the DTC1000 Dat machine, we used to get a lot of these in for service from professional studios like EMI. I use a much later machine and I think it is great. Also have the 510 minidisc which is awful, the transport problems were caused by the microswitches which used to go O/C. Thanks for a really good read, about the best I have seen. I will keep returning to see any updates, I find it hard to believe that the Gainclone can be that good, we used to use a lot of the LM O/P i/c's in the cheaper Sony gear, but I suppose don't knock it until you have heard it !!!

    • Paul
    • Clacton on-sea, Essex
    • 16 January, 2005

    Hi Mark,

    Thanks for doing the site on ROGER SPEAKERS, it's been a joy reading about all the different models there were i did not know there were so many that they had made.I once had a pair of LS4a/2 speakers and i loved the sound of these (my dad owned them but passed away some years back so that's how i got hold of them), any way after some time of using them my dear young son decided to blow them up for me this caused the main drivers to give up "i have still got the tweeters, and crossover in my garage stored up as spares". I have been looking everywere for these speakers eg:hi-fi mag's, internet etc,etc there was one time i saw these speakers for sale that was in a hi-fi mag i think they were going for £70 somewere in london but i lost the sale on them. Well i shall keep looking for them or the next model up from the LS4a/2 (not sure which model that is), i now have a pair of MONITOR AUDIO silver 5i these sound nowhere near as good as the LS speakers. Well thanks for reading this email and keep up the good work,
    yours sincerely
    p clarke

    • O.W. Gilmore
    • Ottawa, Canada
    • 6 January, 2005

    This winter, I decided to learn about PICs and in particular the programming of same. Your site has been the best one yet to get a feel for PIC Programming. I am book marking your site with the intent to visit it on a regular basis for further Programming lessons. If you do add more on the PIC, I would be interested in "interupt operations".
    Keep up the good work!

    • Sheraz
    • Pakistan
    • 28 December, 2004

    I like the site it is good for people who are just starting and exciting enough to rouse up the lazy electronic hobbiests.

    • Sean Pan
    • TAIWAN
    • 27 December, 2004

    Nice job, well done...

    • Gen
    • Australia
    • 21 December, 2004

    Great site Mark, it great to see someone so passionate about speakers. I have just bought a pair of secondhand Studio Ones off my sisters new Husband and they sound fantastic with my Marantz SR6200, but I do find that they are lacking in the midrange when it comes to electronic music such as the Chemical Brothers.


    • Caloy
    • Philippines
    • 7 December, 2004

    Hi Mark! The layout of your site is more organized, but I have to tell you that I was rather sad to see the old site go. I don't know, I just liked the "vintage" feel of the old site.

    Anyway, I'm glad to see you added some additional info on the speakers.

    Good luck!

    • Philip Barsalou
    • Canada
    • 7 December, 2004

    I very much enjoy your site, your designs are very clean. Your preamp is my favorite. Keep up the superior site and work.


    • Dick Cappels
    • Mesa, Arizona
    • 29 November, 2004

    Its really nice to see DIY analog projects on the web. I enjoyed looking over yours.

    Dick Cappels

    • Frans Heuvingh
    • Amstelveen (near Amsterdam) Holland
    • 17 November, 2004

    Although U dont know it yet, your helping a 80 year old radioham (PA0LIZ) on the subject of PIC programming.

    • Winz
    • Thailand
    • 13 November, 2004

    .....I just want to known how to design a pre amp circuit....

    • Claus Wahl
    • Norway
    • 6 November, 2004

    Nice web design, Mark.

    I also admire your well organized work on the preamp - the technical solutions are in many ways equal to mine, but I feel you have allocated much more time to the project than I have. May I steal some of your I/O filters?

    Have been using 8mm character LCD on the prototype and it is just not legible in all lighting conditions. Next approach will probably be a new graphics color LCD (just for the fun of it).

    Keep up the good work!

    • Ant
    • South Africa
    • 30 October, 2004

    Hi Mark
    I've been looking for good, solid intro stuff on 16f84's for a loooong time now - I've only just started reading your info, and it seems to be exactly what I'm looking for, so I'm writing this before I even read further to thank you!
    Good stuff

    • Mark Mathewson
    • England
    • 24 October, 2004

    Nice one! I've found the sections on the pre-amp especially useful. I have a set of Hauppauge MVPs; the main one sits under the telly in the lounge serving audio and video from my Linux fileserver / DVB-T card setup in the garage.

    I've just set up an AVR-controlled LCD interfaced serially to the MVP so I can select and play audio without having to turn on the telly. But I use an old NAD3130 amp (modified with a couple of extra channels for surround) which has no remote.

    I'm not bothered about source selection, but I do need remote volume control. The MVP is rubbish in that respect - about 20dB steps it seems (!) so I want to extend the AVR LCD interface to also control analogue 4 channel audio and use it for both MVP sourced stuff and all the rest by sticking it in the pre-out power-in loop on the NAD.

    Your pre-amp project has given me exactly the analogue volume control pointers I need. Many thanks for that.

    And if you ever get around to the Monoblocks.... I could really do with some more power egor <g> for my MS914s - they're fairly efficient but need tight bass control as although they go low, they have a tendency to waffle. Bi-amping is very much on the cards.

    Anyway - sorry for the long-winded drivel, but appreciate the site. Keep it going!

    • Martin
    • Bromsgrove, Worcs
    • 19 October, 2004

    I bought my A1 back in 1988 and have used it constantly up to last year when I finally replaced it (with an Arcam).

    Because I still love it so much I couldn't bare to sell it and as it still works perfectly I've put it back in its orignal box and even found a pristine brochure and the orignial invoice of £279 that I paid back then...

    • Marcus Ackel
    • Internet
    • 12 October, 2004

    I love this amps (owner of 3) and i love this site
    and Mark is a very nice guy (expert).

    Greez Marcus

    • Sung
    • New Zealand
    • 11 October, 2004

    Excellent redecoration with richer info!! Well done, mate!

    • George Nogalo
    • Canada
    • 2 October, 2004

    Just got on...I am sure I will learn lots!

    • Damien
    • Cornwall UK
    • 24 September, 2004

    nice site n usefull piccys.. tavery much i am looking at upgrading my epos es11's to scm20's n you have helped make my mind up! ta.

    • Manuel Luis D. Dionio
    • Philippines
    • 21 September, 2004

    It is a highly informative site. Thanks a lot.

    • Nick Whitehead
    • Beds-UK
    • 12 September, 2004

    Excellent site, very easy on the eye.
    Great job!

    • Peter Mulholland
    • Norwich, UK
    • 9 September, 2004

    Excellent site, even better now it's redesigned. I like the new clean scheme!

    I eventually plan to incorporate some of your preamp ideas into my home brewed integrated amplifier, specifically the PGA2310 control. It will be controlled by an Atmel AVR though as I hate the PIC's lousy programming style.

    I saw you are moving again, it must be horrible to part with that lovely workshop! I'm still trying to convince my girlfriend to let me have a large shed to use :)

    • Pete Greenwood
    • Darkest Dorset
    • 29 August, 2004

    Hi Mark,
    Absolutely top site !!! - astoundingly good workshop conversion stuff !!... your pages have provided a great deal of the ideas and inspiration for a similar project which I am currently undertaking. Good luck with house (and workshop ?) #2 !!!

    • David Burt
    • Wilmington, Delaware USA
    • 24 August, 2004

    Mark, I was fishing around for info on a pair of small Rogers speakers, and ran across your AMAZING page. I haven't had time to scour it for what I really need, but reading your description of the Rogers LS-2/X blew me away. Clearly there will be more here than I could ever comprehend -- a GOOD thing.

    I am a bit of a dilettante in the world of tube electronics, with all manner of accumulated stuff lying about, mostly ancient things that now represent the bottom of the high end: McIntosh MC40 monoblocks (my favorites by far, especially with the GEC KT66s), a pair of MC60s (ballsy but also very glassy -- don't like 'em), a custom stereo thing made by a guy in California who is a real artiste (SORT of a MC-240 knockoff, not really) and a few low-end tube preamps.

    • Richard Game
    • Orlando, FL USA
    • 24 August, 2004


    Excellent site!!! Very interesting.
    I found it by searching google for 'ATC SCM20' - I have just bought a used pair of the active ones and I am very impressed. Unfortunatly I cannot crank them up as i am in an apartment until november when our house is finsihed.



    • Helen
    • UK, Plymouth
    • 23 August, 2004

    Hi Mark

    I too am a Rogers fan and have a much loved pair of Studio 1 speakers, it's nice to see other visitors here with these speakers, they are rare on the second hand market so it must mean that when we have them we keep them. Sadly I loaned the proper stands to my brother (who lives 300 miles away) and am committing the cardinal sin of using a pair of Rogers Ls4a speakers as stands for the Studio 1's. Looks bloody nice though, elegant black column with the Studio 1's running nude without their grills.

    Regards and best wishes to you, Helen

    • Rick
    • USA
    • 22 August, 2004

    I like your site:
    I need a copy of a Telequiptment D67 Oscilloscope manual. I hope some of your visitors to this site can help me find what i need. Keep up the good work. Regards, Rick...

    • Eric Penot
    • France
    • 10 May, 2004

    Hi Mark,

    Very good site. Very good informations. I have used a CS3310 and plan to use the PGA2310 in a new design...



    • Ayn Marx
    • Australia
    • 16 April, 2004

    Extraordinarily interesting and eccentric site. Came looking for information on Rogers LS3/5A's but hung around and read most of it.

    Site loads & reads faultlessly on Safari for Mac OS X.2.8 & OS X 3.2.3

    • Steve West
    • New Zealand
    • 1 April, 2004

    Great Site Mark,
    Im getting ready to convert one of the bedrooms in my house into a workshop, Your one has inspired some good ideas thanks :)

    • Paul Fredrik
    • Arnhem, The Netherlands
    • 20 March, 2004

    Great site Mark!!!

    Much nice pictures, very interesting projects and easy written!! Discovered my attraction for the quad 405 again too!

    • Chris Homer
    • Eastbourne, UK
    • 27 February, 2004

    Dear Mark

    Nice to see some Rogers stuff on the net. I bumped into your site a year ago, and have only just got round to revisiting it. As a teenager in 1983 I bought a pair of Studio 1s (still my main speakers in my lounge) and recently also inherited a pair of LS2s which my dad no longer wanted! Later as a professional in the computer games industry I set up two studios, one for Philips where I bought LS5/9s and then for a company called Millennium in Cambridge (later bought out by Sony) where I bought LS7Ts. It's a great shame they aren't still around. I went to the Swisstone factory in Mitcham many times, and always received fantastic service. One day I will have the money to demote the Studio 1s to my second pair of speakers, but I've kind of got use to them now ...

    • Maarten van Casteren
    • Cambridge, UK, although I'm Dutch
    • 30 January, 2004

    Nice site and a very nice page on the ATC SCM20's I just bought a pair second hand and I'm going to pick them up on Sunday. Can't wait! It is the old model, though, so not as nice as yours.

    I am a bit amazed that you are driving them with an A1. That must be the most unlikely amp for them, but if it works it's OK I guess. I just hope that my Electrocompaniet ECI 2 will be up to the job.

    Did you find out the values of those inductors in their cross-overs in the end?



    • Vladimir Konev
    • Belarus, Minsk
    • 29 January, 2004

    Hi, Mark!

    It is a very good site!
    A few monthes ago I made a 5-chanells power amplifier based on TDA7294. The results are good. Now i'm searching some matherials about digital volume control and etc.

    Your site is the best about this theme!

    • massimo
    • Italy
    • 18 January, 2004

    great site mate! good job, i'll be back soon!!!!!!!!!!

    • Kelvin Chan
    • Hong Kong
    • 18 December, 2003

    Hi Mark,

    It's a really site and I learn a lot from it, keep up the good work.


    • Sándor Róka
    • Hungary
    • 22 August, 2003

    Hi Mark !!

    It's a very good site. Found when seeking manual for old scope, Telequipment DM63 !! Do you have any information about it, circuit diagram or something. I'm trying to revive it... You are an accurate person and you could have a lots of free time. :-) !
    Keep it up !
    Best regards

    • Mike Drew
    • UK
    • 30 October, 2003

    Hello Mark
    I stumbled across your website, whilst brousing the net (which I do infrequently) for information on Rogers speakers. I too own a pair of LS2a's, and use them as the main monitors in my music studio, together with a Musical Fidelity A1 amplifier. I find this combination very hard to beat, having heard set-ups in other studios. The sound is so natural, without any use of tone control, which is exactly what you need for this particular application.

    If it came to a choice between the speakers, or the wife, I think I'd be waving her goodbye!!!


    • John Taylor
    • UK, NW England
    • 21 October, 2003

    Yes, yes JLH good stuffs.
    Have built 75 watts stereo amp in 1976 and still going strong. This kit was originally bought from Powertran. Still prefers the sound from this rather than the 400 series 45 watts. What is good from 400, is the AM/FM tuner. One can tell the difference bandwidth/depth from different BBC relay stations throwing out the same programs and they say BBC is quality! Some of the independents have better fidelity and banwidths. Having only two stage Alps tuning heart (still remarkable however). I am going to try Larsholts 5008 Varicaps front end.
    Anyone else tried this?

    • Andrei Azzopardi
    • Malta
    • 16 October, 2003

    I'm out of words! Your site is excelent and very nicely explained. I'm still a beginner but I'm gaining knowledge for the time being (theory) so that to use it at full power when actually building circuits. I'm interested in the GainClone amplifier which would most probably be my first circuit. Since I am a senior computer developer, I would also like to try the PIC controllers.

    Thanks for a great site and keep up the good work!!!

    • Fred Pratt
    • Ravenstone Leicestershire UK
    • 8 October, 2003

    Hi Mark,

    This is my second e-mail reply, the first relating to PIC Micros.

    Haven't fully looked at all the content,however. am absolutely fascinated with this web site, excellent is an understatement.

    You are a man after my own heart, in that reading of your interests, and looking at your workshop, is like looking in a mirror. Your Parents must be very proud of their son!!

    Thanks again,
      (Lawrence F Pratt)

    NB How the hell do you ever get the time to do any work ?

    • steve depoix
    • Southampton
    • 26 September, 2003

    Yeah, site very good and easy to navigate around. Your collection of sound eqpt quite interesting and similar in a way to mine. I've gone for good quality older stuff too, Quad, Tannoys, Thorens/Sme, Revox A and B77's etc . Would tactfully suggest you try a more solid mount for the turntable and get it off the pine shelving...but it does look like you've had your hands full over the last two years doing the workshop and shed etc ! :-)

    Once again, great site

    Well done !

    • raffaele fontana
    • 22 August, 2003


    i'm looking for Rogers ls5/9 and if possible stand FOUNDATION Designer for ls5/9,ls3 and studio3. Can somebody help me?

    bst rgds

    • Jacques
    • SA ,Pretoria
    • 18 August, 2003

    Great site!

    I am currantly studying Eletronic Engeneering and found the site very helpfull with my assighnments.



    • Rob Cartwright
    • Wirral England
    • 10 August, 2003

    I am sitting here working and looking for battery monitoring equipment. Stumbled across your site and have been looking at it for over an hour!!!!

    Very good effort indeed!

    Very interesting but must go now and get some work done. (Yes it is Sunday morning, I am self employed so work is 24/7!)


    • Tomas Karlsson
    • Sweden
    • 1 August, 2003

    Thanks for your site. I love the preamp project and has got lots of ideas from your design. Keep up the good work.


    • Jerry
    • East Sussex
    • 16 June, 2003

    Hi Mark

    recently acquired a pair of Rogers LS7's speakers they dont seem well suited to my CD player or perhaps one of the speakers is damaged i dont know? the bass response doesnt sound that good on one channel. Cant get the cover off to check for damage. Sorry Im rambling any way great sight and thanks for info on Rogers speakers. Are rogers still in business if i need to get them repaired???

    Again thanks

    • James Hill
    • Bristol, UK
    • 15 June, 2003

    What a great site!

    Wish i had the time and ability to do something like this, Also you seem to actually finish your projects!

    Best Regards


    • Thepparit
    • Thailand
    • 7 June, 2003

    Hello Mark,

    It is really a good web for DIY audio information. :)


    • Maurice Oden
    • Australia
    • 25 May, 2003

    I am delighted to find a site that appears to know something about Rogers speakers.

    As the company has been taken over I cannot find information about the Studio1 model that I have and I would like to attempt to modify the existing crossover to make the speaker bi-wired. Would you be kind enough to advise me where I could find this info?

    I have looked at the circuit board,but without much electical knowledge and a circuit diagram, I have very little idea of how to proceed. I had thought of simply breaking the copper connections to the tweeter on the circuit board at the amp input and leading the tweeter connections out to 2 new terminals on the back of the cabinet. But which connections???? It is a puzzle!

    • Scott (SAWZALL)
    • Washington DC, USA
    • 16 May, 2003

    A rather sweet website... Will be quite interested if you take your preamp to the DIY market.

    • Francois
    • Venezuela
    • 14 May, 2003

    Good place..., your website is interesting... much success in your projects

    • Andries
    • Holland
    • 14 May, 2003

    I realy like your way of building the amp, and think i'll give it a try. I have a question however, would it be possible to use the gainclone as a guitar amplifier, and what kind of a preamp do i have to use,to lift-up the input sensitivity to about 20mv. Do you have a sugestion, or more usefull, a schematic ?

    You've build a real nice and simple to copy amp, and your website is really top of the tops ! ! !

    Best regards,

    • ShOoPoO
    • Canada
    • 13 May, 2003

    looks good:)

    • Matt Wenham - DoctorRad
    • UK
    • 6 May, 2003

    Hi Mark, Found your pages on a Gainclone search, some very nice stuff you have going on here.

    I think you might find Ben Duncan's writings on preamp design a bit of a eye opener. Try contacting Audio Synthesis for reprints of his AMP-01, AMP-02, PAS-01, PAS-02 and CD Player mods from Hifi News. I only have AMP-01 these days unfortunately, but most of the groundwork on how op-amp circuits behave in the real world is covered in this text. Suffice to say, for DIY projects, it really is worth avoiding spoiling the boat for a ha'ppeth of tar and going for better op-amps than 5532s. But as you point out, they may well be 'good enough', and they're cheap to replace when things go wrong.

    My current thoughts are leaning towards trying a Gainclone with a fully regulated supply. Naim have been doing it since the 70s, but thankfully, Moore's Law apparently applies to analogue chips as well as digital. You can now get stupidly cheap, stupidly good (value) chips to do pretty much anything. It's a New Golden Age, it really is.



    • Darren Latto
    • Arizona USA
    • 24 April, 2003

    Great personal web page. Cheers!

    • Stefano
    • Italy
    • 20 April, 2003

    A nice site for diy

    • John Alan Woods
    • 17 April, 2003


    • Mike Palmer
    • Brisbane, Queensland, Australia
    • 14 April, 2003

    Now that my interest in something I contemplated years ago has been rekindled............... onward and upward !! I like your implementation, and it has given me a good head start as I journey toward creating my preamp......


    • Pete Ream
    • Notts UK
    • 14 April, 2003

    Hi Mark,
    Well i can only wish to aspire to your level of expertease. Great site and a superb work shop, hope my garage extention will take on a similar look (i doubt it) internally. Having had a blip with the old hi-fi diy and stuff going bang! this site gave me the lift i needed. Shame you dont live in my town..........

    • Colin Hepburn
    • 10 April, 2003

    Pages of interest: Diy and your approach to the Gainclone Amp

    • Paul M Thomas
    • UK
    • 6 April, 2003

    Hello Mark!

    This is a really good website!

    Just like you I have an accumulation of Hi-Fi around the house and have always had this interest for as long as I can remember.

    I have been a fan of the BBC sound for sometime so in my main system I have Spendor SP1/2 biamped with Audiolab 8000C ans 2 x 8000P. This sounds very natural and easy going. I found the internal wiring of the Spendors not that good so I replaced with new heavier wire soldered direct to the crossover and speaker unit tags.

    Upstairs I have (courtesy e-bay) Quad 33/303/FM2 ans Tannoy Mercury M2.5 speakers. The 33 I cleaner up the switches and squeezed the internal multiconnectors closer together to remove an intermittent fault. Next 303 capacitors changed (courtesy Avondale). Finaly for FM2 (a valve/transistor hybrid) a full service from onething audio and a new modern decoder fitted. This set gives a fantastic clean sound punchs but easy to listen too. I also heard more detail on CDs through it. I am not sure now which sytem is best - which proves all Hi-Fi is a compromise. I am still a big fan of the old Quad designs even if there is evidence of cost cutting in the components - you have to respect an amplifier if it is still sounding good at 30 years old! My only other prized Hi-Fi item is a 1/2 track Revox G36 valve tape recorder (serviced a few years ago with only minor component upgrades) which provides fantastic recordings of live broadcasts.

    Good listening


    • PJ
    • Sweden...
    • 29 March, 2003

    Great site...
    Really has given me inspiration to keep on building my own stuff...

    • John Bell
    • UK
    • 18 March, 2003

    Excellent site, a great read! You and I have a great deal in common. My company was based immediately next door to Rogers Loudspeakers for 18 years and we also developed and made the PCB's for the Musical Fidelity A1 and all MF amps from No 1 until 1990/91 when MF decided to have them all made in the far east! Yes, like much of the UK hifi industry, the guts of the amps (not the final assembly of course) are made in places with names I cannot pronounce!

    • Frank Mc Alinden
    • Aus...
    • 4 March, 2003

    Hi Mark,
              One of the guys on the UKHA Home automation list mentioned your site for some pic info so had to have a look...Just drooled looking at the workshop photos and although not an audio electronics type found the articles interesting...Looking forward to some more pic projects..
    keep up the good work

    • John Morcom
    • Canterbury, UK
    • 23 February, 2003

    I liked your site very much.

    I've also put together a PGA2310 based pre-amp (using 3 of these devices to give 5.1 surround controlled by PIC16F877 with optical encoder for volume and VFD display - a case of great minds think alike?) and have been very pleased with its sound quality.

    • James Curtis
    • New Zealand
    • 22 February, 2003

    Hi Mark,

    great to finally find a site with excellent information on Rogers speakers. Very hard to find now in NZ.

    I bought my pair of LS2a/2's 10 years ago and, with the exception of a pair of Proac Tablettes at 3 times the price, have heard nothing to match their unique, smooth sound.

    I lost the manuals for them a while back now during a move so thanks for posting them, great to re-read and have on file. Love the site!


    • Allan Kragelund
    • Denmark
    • 17 February, 2003

    Hi Mark, Impressive site you've got here, must have cost you a lot of time and effort! Found you while browsing the web for articles on the ATC SCM20SL. Very fine little speakers indeed, got a pair myself. Unbelievable clarity, perspective and dynamics! They were the first speakers to be found worthy of replacing my trusty old Quad ESL 63's. Give us some more impressions/data the ATC's when you find the time... Best regards/Allan

    • Andrew Thompson
    • Cambridge, UK
    • 5 February, 2003

    I was thinking of trying a PIC bassed pre amp a while ago, but I was put off slightly by all of the effort involved in knowing what to do and writting the code. But, after seeing what you have achieved here with your pre-amp I feel as though I should take another look at it. Just one thing though, how long have you been working on this for? Should I cancel my social life now, or will I survive?

    • Gary Morton
    • UK
    • 13 January, 2003

    Great looking site. Very impressed with your scope fix!

    • Lee Edmunds
    • Walsall, UK
    • 7 January, 2003


    What a site. I am in the early stages of converting my garage and I must say you have given me some food for thought. We're also partitioning down the middle with the warm part being a computer/play room for the kids (and me!)

    Great work - keep it up

    Lee Edmunds

    • Paul Williams
    • Portsmouth, UK
    • 14 December, 2002

    Thanks Mark, really good stuff, good content and style! I had been a Z80 fiend in the early days until the Mrs made me put away the 'bits of wire'. My son now has a GCSE project with PICs ('F627 flavour) and I am trying to catch up, but I recognise the principles are the same for all PICs. I also find is useful.

    Keep up the DIY, but don't forget some ventilation with the insulation etc. Professionlly I too often come across 'damp' when in fact it is condensation either on the surface or as interstitial condensation - so try to use a vapour barrier to keep it dry but let it breathe. Oops sorry, I'm lecturing... Bye.

    • Leo Lau
    • Hong Kong
    • 28 November, 2002

    Excellent! Good Diy Website...I'm wait for new projector...

    • John Daniel
    • Bedfordshire, UK
    • 27 November, 2002

    Hi Mark,
    Really nice site.
    I hate how tidy your workshop looks. Hard to warrant any work goes on there ;-)
    Linked to your site from DIY audio forum.

    • Bami
    • The Netherlands
    • 25 November, 2002

    Good site...:)

    • Brian Phillips
    • Iver Bucks, UK
    • 25 November, 2002

    A great site, Mark. How do you find the time to maintain it?

    We have a lot in common - BBC, IPK cases, RC volume controls, pcbs that are a work of art...

    Keep up the good work, and thanks for the tip on the new displays.

    • Jeff Chen
    • Taiwan
    • 19 November, 2002

    Hi Mark:
    I'm very interest in your Dual PSU, also like your remote control preamp.

    • Bill Annau
    • Edinburgh Scotland
    • 25 November, 2002

    Hi. Love your site. I am likewise a lover of Rogers loudspeakers; I have LS7s, Studio 1s and until recently, LS5/8s (ex BBC Edinburgh). My first Rogers were LS6s, but I found I needed more bottom end, hence, the LS7s. Unfortunately, my Studio 1s were damaged when my Cyrus II amp blew it's o/p. However, I have replaced the damaged LF unit, but noticed that some of the capacitors on the crosover were a bit discoloured. Do you have any info on the components used in this xover? I would like to replace the offending components but can't identify their values because of the discolouration. Hope you can help.

    Bill Annau

    • Koi Lee Loh
    • Singapore
    • 15 November, 2002

    I own a MF A1 and the input selector is faulty as I do not hear definite clicks. Just a smooth turn to select one input from another. Just checking to see if you have a solution.


    • Arnold Lieberman
    • Essex, UK
    • 14 November, 2002

    Amazing site! You're doing all the sorts of things that I never seem to have time for (kids, wife in the way). I've not started on PIC programming yet, but it looks like the way to go, if i can't get my HTPC doing what I want it to do.

    • Laurie K.L.Chan
    • Hong Kong
    • 14 November, 2002

    Dear Mark,

    It is a pleasure to visit your site. Great work. I am experienced in analogue but not digital (I belong to the older generation). I don't quite understand the digital volume control with the BB chips.

    I wish to implement such control into my IC preamp project that uses the current feedback chips in parellel config which already designed. I am wondering if you could help me with straight forward circuit diagram with BB volume control with remote function and FL display?
    Best regards

    • Richard Savary
    • Quebec City, Canada
    • 12 November, 2002

    Simply astonishing.....

    How did you get all this information ???

    I've search for a long time information regarding the A1. Seems my "quest" has finally come to an end !!

    On top of that, you had the presence of mind to ad on your web page a "bookmark" shortcut. An additionnal bookmark with my existing 200 audio links....

    • quan vu
    • USA
    • 10 November, 2002

    Very good site.
    keep up the good work.
    any further follow up with ls5/9, please post :)

    • Tony
    • Essex
    • 4 November, 2002

    Excellent Site. Just wish mine was this far advanced (damm new javascript ideas keep forcing re-writes). Don't know where you get the time. I'm just getting into Pic's so I read your pre-amp project with interest. Keep up the good work, I'll check back soon. Hopefully with my F9 website up and running too.

    • Roberto
    • ITALY, Rimini town
    • 30 October, 2002

    BEST SITE!!!!



    • Claus H
    • Denmark
    • 29 October, 2002

    Really Cool site..

    • David John
    • Malaysia
    • 20 October, 2002

    I had an A1,then the Typhoon.They both had similar problems with volume levels and am happy to see how you overcame them. I have bookmarked your site and will re-visit to see your updates. Thank You.

    • prugnieres philippe
    • France
    • 24 September, 2002

    You have a good site for inovation audio good luck for continuation.

    • William Cameron
    • Dunstable, Beds., UK
    • 7 September, 2002

    Hi Mark, stumbled across your site whilst "googling" for info on Rogers LS7s! I've really enjoyed browsing it, even though much of it is over my head electronically... superb lay-out, easy to navigate, well written, informative, etc., etc - I'll let you add extra superlatives:-)

    Just to add that I'm on my 3rd pair of LS7s...I just can't seem to find anything else that's as complete sounding! I was toying with the idea of bi-wiring, and was interested to note your comments - food for thought...
    Anyway, you're now book-marked - keep up the good work!
    Best wishes,

    • Chris Found
    • UK
    • 27 August, 2002

    Excellent site, would like to converse with you about the pic routine for the preamp, have done some work on two designs one which is on my site and the other is in my living room.

    • tony
    • Australia
    • 14 August, 2002

    great site,particularly rogers speakers information

    • ron mackay
    • UK, Scotland!
    • 31 July, 2002

    Just got a pair of 5/8s myself, modded with neutrik 4w connectors (speakcon) and working on re-laminating with a nice light burr eucalyptus possibly. They were bashed but good nick ex-BBC. The amps are next years work. Interested in your Preamp but OTT for me may build Doug Selfs kit with extra i/p and shove a balancing and H/P stage on the end. You spend some time on the site but worth it! I know from pratting about on mine, not for release yet. Ron

    • Richard Thompson
    • UK
    • 27 July, 2002

    Great web site !!!

    All the info on Rogers LS 5/8s remind me of my time in BBC BH London 84-88.

    Well done on an excelent site.

    Cheers Richard Thompson.

    • David Lugosi
    • EU, Hungary
    • 19 July, 2002

    Hello Mark, I just sit here with fallen cheek. Never seen such precise and thorough handwork documented free for DIY-ers. Almost all DIY stuff on net is realized in crap quality. If not, it is no DIY any longer. To me you are the first who takes all the bother to make things as professional as possible and share the result with the DIY community.
    All the best and keep on creating such things!

    • Marcello Pellerano
    • Italy
    • 5 July, 2002

    Great site, Mark.
    I built an LS3/5A clone, years ago, and I recognized the whole project. And the other stuff is very interesting, too. Very nice job, really.

    • Iain Lamb
    • UK
    • 11 June, 2002

    A splendid bit of work. You've definitely got a sense of humour, and at the same time passionate about your work.

    I am particularly fascinated by the A1 stuff. I have one too, and for a long period I was utterly addicted to it. I rediscovered my music with it. Took it to bits when I got home, and like you was alarmed at the lack of heat transfer compound between U section and heat sink.

    • Les Wolstenholme
    • Chesterfield
    • 27 May, 2002

    Very nice site which is informative and easy to navigate.
    Should enhance the hobby of audio 'tweaking' to a lot of folks.

    Best wishes for the future,

    Les - Avondale Audio - Chesterfield UK

    • Edgardo
    • Argentina
    • 24 May, 2002

    Beatifull and interesting page. Congratulations.

    • John Emmerson
    • London UK
    • 16 May, 2002

    Mark, Thanks for the excellent info on the Rogers LS7. Nice to find someone who appreciates the qualities of this older stuff, and even nicer to find someone who wants to share his info with the rest of us. After reading your pages I now aspire to a pair of LS5/ day. Very interesting project pages too, nicely presented, and I look forward to seeing what else you come up with.

    • Stefan Gustavsson
    • Sweden
    • 2 April, 2002

    Thanks for good info about the A1! I've two of them but they are both broken right now ... I haven't repaired them mostly because the very irritating mechanical construction. It's hard to troubleshoot when you can't run it without the top on ...

    But I've to fix them soon because it's a well sounding and classical amplifier. When I've both up and running I can disable my radiators ;)

    Regards Stefan.

    • Andrew
    • Australia
    • 2 May, 2002

    Very interesting and useful. Also very informative. Keep up the good work..

    • Miki
    • Canada
    • 1 May, 2002

    Excellent site. Keep up the exelent work.

    • Pedro Martins
    • Portugal
    • 4 April, 2002

    Hi! Just great! Nice design and easy navigation. Keep going and I'm waiting for more material here. I'm a DIY'er too. See:
    It's in portuguese, of course ;)
    Soon in english.
    Best regards.

    • P.W. Ramlix Leung
    • Hong Kong
    • 31 March, 2002

    This is a excellent DIY web site! I am looking forward to see more good and new DIY web pages in this web site! Well done!

    • Michael Bornemnan
    • Germany
    • 25 March, 2002

    Hi Mark, it's a great site, indeed. I'm thinking about buying a A-1 David, perhaps i will be so lucky to get it.

    "Into the Blue"

    • Jacky Liu
    • China
    • 14 March, 2002

    Very good personal website! Especially helpful for my MF A1 amplifier. Thank you very much!

    • Wolfgang Schulz
    • Germany
    • 10 March, 2002

    Thanks a lot for the detailed information about the A1.

    When I found your site I actually was looking for a circiut diagram to fix my Rotel MB 100 mono blocks. But I'm also interested in buying an Musical Fidelity.

    Chears Wolfgang.

    • Simon Clark
    • Berkshire UK
    • 23 November, 2001

    Great site Mark.

    Love the A1 critique and mods. Makes me want to have a go at my A100. Us Breville grille owners need to stick together.

    • Nick Roberts
    • I think...
    • 16 January, 2001

    NICK woz Ere.... Great site...Needs more Pyros!

    • Mark K
    • Saxlingham Thorpe (centre of known universe)
    • 15 January, 2001

    Hello Mark- A great site - the workshop - I want one just like it please! Very interesting account of the `scope mods, and the Nicam unit.