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    Mark III's upgrade or keep original? (what would you do?)



    Posts : 1
    Join date : 2012-08-27

    Mark III's upgrade or keep original? (what would you do?)

    Post by nwsailboat on Mon Aug 27, 2012 6:37 pm

    I have had my mkIII since the 80's. Use them almost every day, never had any problems even with the 6550's in them and (most important) never upgraded the quad cap or selenium rectifier, they bias out fine. Then I read the dangers and got worried.
    I bought some new chassis' a long time ago and new boards, caps, quad caps, everything except the transformers just recently from DynaKits.
    My thought was to rebuild them, but the only parts I do not have are the transformers and my thought was to use the old transformers.
    Then I started thinking again (oh no!), what if I left the old mkIII's in original state and bought new transformers to finish off the new mkIII's.
    So, my question after my long diatribe is (what would you do):
    1. leave the old mkIII's alone and enjoy listening to them?
    2. rip the transformers out of the old mkIII's and use them in the new mkIII's?
    3. buy new transformers, finish off new mkIII's and keep the old mkIII's as original and put away?
    If I have been using the old mkIII's this long, is there still a high risk of damage?
    Thanks, Phil
    Bob Latino

    Posts : 2634
    Join date : 2008-11-26
    Location : Massachusetts

    Re: Mark III's upgrade or keep original? (what would you do?)

    Post by Bob Latino on Mon Aug 27, 2012 8:16 pm

    Hi Phil and welcome to the Dynaco Tube Audio Forum ...

    There are two ways to look at your situation ... Do I want ...
    1. The highest value of the amps
    2. The best sound I can get out of my amps

    Altering your original Mark III's in any visible way (even to update the amp for better sound like a new driver board) will devalue the amp. Updating a few capacitors/resistors inside the amp won't really devalue the amp.

    I would vote for choice #3 that you list below. Keep the original Mark III's and put them into semi-retirement. Buy new transformers and complete the build on the two new chassis that you have. I would take out the originals every now and then and run them a little. Complete disuse of a tube amp over long periods will in time cause the electrolytic caps to go bad.


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