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    VTA ST 120 option?


    Andy Jersey

    Posts : 69
    Join date : 2012-09-29

    VTA ST 120 option?

    Post by Andy Jersey on Sun May 12, 2013 9:04 am

    I was thinking. Bob Latino had said he didn't optimize the 120 for the KT-120 because there was only one manufacturer and if the stopped making them we'd be out of luck. I was wondering how hard it would be to modify circuitry to take full advantage of the tube or whether it would be a wasted exercise. Anybody want to chime in? (Bob you're invited).


    Posts : 304
    Join date : 2010-02-03
    Location : Costa Rica

    Re: VTA ST 120 option?

    Post by baddog1946 on Sun May 12, 2013 9:18 am

    I know I am curious. How can it be done?

    Bob Latino

    Posts : 2382
    Join date : 2008-11-26
    Location : Massachusetts

    Re: VTA ST 120 option?

    Post by Bob Latino on Sun May 12, 2013 9:52 am

    In order to take full advantage of the KT120 tube's operating parameters, you would have to create a circuit, power transformer, power supply etc. that could deal with 100 to 120 milliamps of current flow per each KT120 tube at a B+ of maybe 600 - 625 VDC. You would need a power transformer capable of 500-0-500 VAC on the secondaries and a cap board maybe using 350 VDC caps in series for a 700 VDC power handling capability.

    The items listed above do not come cheap. There is no question that an amp like this could be built and/or offered in kit form. The real question is would enough people buy this amp in either kit or wired form to the point where it could be economically feasible for a manufacturer to offer the amp for sale?



    Posts : 6
    Join date : 2012-03-03

    Re: VTA ST 120 option?

    Post by SpotcheckBilly on Sun May 12, 2013 6:35 pm

    It seems that several manufacturers have already switched to the Tung-Sol KT120 output tube including Conrad-Johnson, Audio Research, and Rogue Audio. I don't think that the KT120 is going to go away, but there's no reason that KT88's or KT90's couldn't be substituted if necessary.

    According to Mark O'Brien of Rogue his KT120 amps are big sellers.

    I think there would be a decent sized market for another KT120 power amp, or even an intergrated if you wanted to do something really interesting Wink


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