push-pull? What's going on here?

[Ethan]

Last weekend I rebuilt a 1954 Gibsonette amp that had been awaiting restoration. I had thought initially that it used two 6V6 tubes in parallel like a BR-9, but on closer inspection I found that the 6V6s shared only the cathode resistor and screen supply. The plates are connected to separate leads on the O.T. and the signal is sent to only one control grid. The control grid of the other tube is connected to ground.
Is this a primative push-pull arrangement? There is only one preamp stage (a 6SJ7) and no PI. It seems like an awfully simple circuit to cause brain-freeze, but I just don't understand how this power stage works.
Anyone care to take a stab at explaining it to me?

Ethan

[Newt]

The schem for the GA-8 Gibsonette at schematic heaven shows a parallel 6V6.

http://www1.korksoft.com/~schem/gibsona ... onette.pdf

[Ethan]

That's true. But this isn't a GA-8. It's the early version of the Gibsonette: 1954 and earlier. The circuit I described is accurate, I just don't understand how it works.

Ethan

[Ballz]

I think you have stumbled on what´s called a "self-split" power stage. Check this link...is it something like this? If it is, a good explanation of its use is given in the text.

Cheers /Richard

http://www.triodeel.com/compact.html

[Ethan]

Richard,

Outstanding! That is exactly the type of circuit in my Gibsonette. I knew someone here would recognize it!
Thanks for the great link-

Ethan

[Ballz]

/R