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    KT120s using PA060 PT in ST70.

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    gener8r

    Posts : 59
    Join date : 2012-04-28

    KT120s using PA060 PT in ST70.

    Post by gener8r on Wed Jun 28, 2017 4:07 pm

    From what I read on here it seems the train of thought regarding KT-120s is not to use them in a ST70 using the PA060 PT because of current draw, unless it is an "upgraded" PT.

    I can understand this with the original PT, but the newer ones sold by DynakitParts and Triode?  Or are they considered "upgraded transformers"?

    If not then how is it the newer PA060s with EL34s/6550s/KT88s and the VTA 6SN7 octal driver board combo is not also a current draw problem as it will require 1.6+1.6+0.6+0.6 or 4.4 amps on one side and 1.6+1.6+0.6 or 3.8 amps on the other?

    The KT120s and the VTA noval 12AU7 driver board combo actually draw less current then the above at 1.9+1.9+0.15+0.15 or 4.1 amps on one side and 1.9+1.9+0.15 or 4.0 on the other.

    It could even be less current as the specs say a KT120 draws from 1.7 to 1.9 amps, but I used the high side.

    The KT120/12AU7 combo looks to be a better balance side to side than the 6550/6SN7 combo and it seems well within the 5 amp output of the 6 volt taps on the newer PA060s.

    What am I missing here?   Is anyone using KT120s in their ST70 that can report back?

    I'm trying to determine if I can use these KT120s I just got, or if I should let them go and order KT88s.

    Thanks.  Any thoughts are appreciated.
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    corndog71

    Posts : 580
    Join date : 2013-03-19
    Location : It can get windy here

    Re: KT120s using PA060 PT in ST70.

    Post by corndog71 on Wed Jun 28, 2017 4:51 pm

    ST70 should use EL34 / 6CA7. KT66, KT 77 with regular transformer. With improved PT KT88, 6550 can be used. KT120 are not recommended!

    ST120 can use KT88, KT90, KT120, and 6550.

      Current date/time is Mon Dec 11, 2017 5:39 am