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    Dynaco Mark III stock board

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    sushimaster

    Posts : 7
    Join date : 2009-08-09

    Dynaco Mark III stock board

    Post by sushimaster on Mon Oct 12, 2009 10:01 pm

    Greetings. I have a pair of Dynaco Mark III that I am attempting to restuff the original driver board. I drew a schematic. But I'm not sure if it is 100% correct. There are two parts that I think I might have switched, but I'm not absolutely certain. Can someone please double check that I have the right parts listed in the correct location? Thanks.

    - Sushimaster


    Bob Latino
    Admin

    Posts : 2411
    Join date : 2008-11-26
    Location : Massachusetts

    Re: Dynaco Mark III stock board

    Post by Bob Latino on Tue Oct 13, 2009 8:07 am

    The Dynaco Mark III kits came with all the parts preassembled on the board. To my knowledge Dynaco never listed a board parts layout for the Mark III. One minor thing that I see is you have "6A98" for the tube when it is a "6AN8". If you are rebuilding your two Mark III's to play on a daily basis I would recommend that you not use the ORIGINAL driver board. The original driver boards were made of a brown phenolic material with open solder traces that does not withstand heat very well. Many of these boards developed cracks in the open solder traces. The usual symptom of a bad solder trace was one channel that developed noise or simply cut out after the amp warmed up. The Mark III came out in 1957 and some the original amps still in circulation are over 50 years old and probably have thousands of hours on them.

    IMHO you are better off (if you want to keep the driver original circuit) to purchase two new driver boards and parts sets from Dynakitparts. The Dynakitparts boards are made of modern .062 FR4 material and are much more heat resistant than the original Mark III boards.

    Mark III repacement boards

    Bob

    sushimaster

    Posts : 7
    Join date : 2009-08-09

    Re: Dynaco Mark III stock board

    Post by sushimaster on Tue Oct 13, 2009 10:37 pm

    I think I figured it out. Thanks Bob for pointing out the N, I dont know why I put a 9 there. I think I'm gonna purchase a blank new board from dynakitparts.com and stuff it myself. The assembled one is more than I would like to spend.

    Here is what I think the schematic should be. Could someone please double check it for errors? Feel free to distribute it, modify it and use it any way shape or form. It is my contribution to the Dynaco community because I am a Dynaco fan.



    - Sushimaster

    vargasmongo3435

    Posts : 4
    Join date : 2013-02-17
    Age : 46
    Location : Puerto Rico

    Re: Dynaco Mark III stock board

    Post by vargasmongo3435 on Fri Feb 22, 2013 1:37 pm

    Hello

    so that might look like this?







    with all my respect of course, this is a bit more heavy duty board, "prototype"

    but I wish to know the measurements of the board in millimeters.


    Regards
    Juan

    quad

    Posts : 14
    Join date : 2010-11-25

    Re: Dynaco Mark III stock board

    Post by quad on Sat Feb 23, 2013 1:30 pm

    vargasmongo3435 wrote:

    but I wish to know the measurements of the board in millimeters.

    Regards
    Juan


    http://www.diytube.com/phpBB2/viewtopic.php?f=11&t=5636

    vargasmongo3435

    Posts : 4
    Join date : 2013-02-17
    Age : 46
    Location : Puerto Rico

    Re: Dynaco Mark III stock board

    Post by vargasmongo3435 on Sat Feb 23, 2013 2:37 pm

    Thank you quad really good info I appreciated.

    Regards
    Juan

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