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    Upgrade boards for MK IV

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    howlin' hoosier

    Posts : 29
    Join date : 2012-04-30

    Upgrade boards for MK IV

    Post by howlin' hoosier on Mon Apr 30, 2012 12:44 pm

    Checked with Roy at tubes4hifi in regards to upgrade boards for the Dyna MK IV amp. Roy replied that he used to sell them, but they were almost a non-seller and are no longer produced. Anyone have a pair to spare? My IV's are stock save for a resistor here and there, as well as the coupling and quad caps, and I'm curious to see what more can be achieved with mods.

    Luddite

    Posts : 235
    Join date : 2009-02-04
    Age : 66
    Location : Texas

    Re: Upgrade boards for MK IV

    Post by Luddite on Mon Apr 30, 2012 2:28 pm

    You can get fiberglass replacement boards (original Dynaco circuit) from http://www.dynakitparts.com/store/catalog.aspx?cid=11 These are available either blank or with (upgraded) components. You can choose either metal film or carbon composition resistors if you order them with components. Prices range from $20.00 to $70.00 each.

    Best Regards,
    Charlie

    jhoak

    Posts : 46
    Join date : 2009-10-16
    Age : 58
    Location : Central Florida

    Re: Upgrade boards for MK IV

    Post by jhoak on Mon Apr 30, 2012 2:42 pm

    If you can't get your hands on a pair of VTA boards check with Triode Electronics. They sell driver board upgrades for MK IVs.

    My very first tube amps were a pair of MK IVs. They had been rebuilt and upgraded with the Triode boards.

    hawaii.ken

    Posts : 157
    Join date : 2012-01-31

    Re: Upgrade boards for MK IV

    Post by hawaii.ken on Mon Apr 30, 2012 3:20 pm

    Curcio offers upgrades too:

    http://www.curcioaudio.com/dynadr_3.htm#DYNACO%20MARK-4%20MONO%20POWER%20AMP

    howlin' hoosier

    Posts : 29
    Join date : 2012-04-30

    Re: Upgrade boards for MK IV

    Post by howlin' hoosier on Mon Apr 30, 2012 8:26 pm

    I'm going to hold out and see if I can't get a pair of the VTA boards - thanks for all the suggestions!

    danf

    Posts : 58
    Join date : 2009-01-19

    Triode boards for Mark III/IV are first rate

    Post by danf on Tue May 01, 2012 9:01 pm

    I've built Mark IIIs with both VTA and Triode boards. Both sound excellent. The Triode boards were somewhat less fuss to get operating at a high level. The circuit is based on the superb Grommes 260. If Roy is out of the Mark IV boards, I wouldn't hesitate to use the Triode boards. For the ST-70 I would go VTA all the way, but for the monoblocks you will be happy with the Triodes.

    tubes4hifi
    Admin

    Posts : 1261
    Join date : 2008-11-30

    Re: Upgrade boards for MK IV

    Post by tubes4hifi on Wed May 02, 2012 8:45 pm

    the ONLY boards I can recommend for the MK4 amps (unless you want to modify a pair of my MK3 boards) are the
    DIYtube boards, better than any except mine!

    howlin' hoosier

    Posts : 29
    Join date : 2012-04-30

    Re: Upgrade boards for MK IV

    Post by howlin' hoosier on Wed May 02, 2012 9:47 pm

    tubes4hifi wrote:the ONLY boards I can recommend for the MK4 amps (unless you want to modify a pair of my MK3 boards) are the
    DIYtube boards, better than any except mine!

    I'm not opposed to making some changes to the MK III boards - what sort of surgery are we talking about?

    tubes4hifi
    Admin

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    Join date : 2008-11-30

    Re: Upgrade boards for MK IV

    Post by tubes4hifi on Wed May 02, 2012 10:25 pm

    the PCBs are actually the same exact size, but different mounting holes, so you'd have to drill new mounting holes, and one component (an output coupling cap) would need to be moved slightly, pretty minor surgery actually, so if that's OK, just go back to my MK3 webpage and order them.

    howlin' hoosier

    Posts : 29
    Join date : 2012-04-30

    Re: Upgrade boards for MK IV

    Post by howlin' hoosier on Wed May 16, 2012 9:59 am

    tubes4hifi wrote:the PCBs are actually the same exact size, but different mounting holes, so you'd have to drill new mounting holes, and one component (an output coupling cap) would need to be moved slightly, pretty minor surgery actually, so if that's OK, just go back to my MK3 webpage and order them.

    I've just ordered a pair of the MK III boards - email sent with a few questions - thanks in advance!

    hawaii.ken

    Posts : 157
    Join date : 2012-01-31

    Re: Upgrade boards for MK IV

    Post by hawaii.ken on Sat Mar 02, 2013 7:52 pm

    I'm wondering how this turned out? Got pics?

    Pooch

    Posts : 53
    Join date : 2009-12-01
    Age : 66
    Location : Wa

    Re: Upgrade boards for MK IV

    Post by Pooch on Thu Mar 07, 2013 9:00 pm

    Yeah, I'd like to know, too. I've got Roy's boards on my mk4s and can vouch for them. Haven't heard any other boards, but from rolling caps on Roy's boards, I can tailor the sound the way I like. By the way, just an aside, after I had a new multi section can cap fail, I bought Curcio's power supply board and filled it with panasonic caps. I don't know if this made any difference in the sound, but it is reliable so far.

    tubes4hifi
    Admin

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    Join date : 2008-11-30

    Re: Upgrade boards for MK IV

    Post by tubes4hifi on Thu Mar 07, 2013 9:43 pm

    well, nobody ever posted any photos, so I dug up some from about 3 years ago. This is from when my MK3-MK4 board was the same board (2 sets of mounting holes).
    They are a tight fit. But I won't make more unless about a dozen people need them, otherwise, just drill new holes in my MK3 board.



    Pooch

    Posts : 53
    Join date : 2009-12-01
    Age : 66
    Location : Wa

    My mk4 boards...

    Post by Pooch on Fri Mar 08, 2013 3:46 pm


    tubes4hifi
    Admin

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    Join date : 2008-11-30

    Re: Upgrade boards for MK IV

    Post by tubes4hifi on Fri Mar 08, 2013 3:48 pm

    POOCH
    looks like you had an older set of MK3-MK4 boards also - where are the 2 or 3 customers who bought boards from me these past two years?

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