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!

Guestbook entries from 2008 (28)

    • 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