HI guys
The advantages of using PP amps is the fact that the input and output
capacitance is in series so the
I/O "c" is 1/4 of when compared to an parallel Amp.
Another is the balance which " automatic" gives a supression of the even
harmonics
A general made fault is that the bias for the tubes is typically only made as
paralelling the
DC supply for the grid 1, / cathode - and the bias current meassured is a sum
of those currents.
So if not bought as " a set" compared or what we call it, a good Amp can with
ease show hidden
distortion , inspite looks good. This has nothing with the general Amp. to do
thats obvious.
So eigher matched pair - or a bias supply for EACH tube, individually
adjustable.
Vy 73 de OZ5IQ, Kim
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