Odd PI from screen grid circuit Magnatone Melodier 109

[chopstuck]

I found one of these 2x8 amps locally. Seems like a fair deal.
I haven't seen this circuit before where the second tube of a push-pull pair is driven from the screen grid of the first.
How does this sound ? Does the PI impart a characteristic tone ?
The schematic is in the second link

http://www.vibroworld.com/magnatone/109.html

http://www.geckoamps.com/magnatone109/

[teemuk]

It works in push-pull fashion up to the point where the tube receiving input to its grid starts clipping. At that point it starts to operate more like a single-ended circuit.

So, when you overdrive that thing it will behave moore like a SE amp than a push-pull amp: Clipping distortion will be asymmetric and harsher.

[Structo]

Looks like a cool find.

What kind of shape is it in?

[chopstuck]

OK figured out it's a self-split inverter.

Teemuk, are you describing a clipping that gets suddenly ragged when the first tube distorts ?- that it goes from clean to dirty with a hair trigger ?

I know my old Magnatone Varsity was pretty ratty in a cool way but the cab was too small. I haven't played this amp yet but with two 8"s in a bigger cab..... I hope to see it today.

Marc

[chopstuck]

Rats, the guy sold it before I could get there.

I guess $250 was too good of a price to last.