New PP amp...

[Jetbat]

Ok. That's where I was confused.

Thanks
Scott

[FerdinandII]

I think I know what Jetbat is referencing.....
Some people call this a Cathode Coupled circuit. They claim that the cathode of V1a is "driving" the cathode of V1b, which then makes the behavior of V1b look a lot like a grounded grid stage (AKA Common Grid). Not saying this is right.......

Isn't V1B a common grid stage? Or does that change with the grid tied to the R8-R9 junction?

Scott

No, it's a standard common cathode stage. Input is the grid, output from the plate. The connection of R2 to the junction of R4 & R7 just provides a DC feedback to keep the bias current in the output tubes more stable (as does the R1/R3/R6 combo).

Roscoe

[Roscoe Primrose]

I think I know what Jetbat is referencing.....
Some people call this a Cathode Coupled circuit. They claim that the cathode of Via id "driving" the cathode of V1b, which then makes the behavior of V1b look a lot like a grounded grid stage (AKA Common Grid). Not saying this is right.......

I think 'cathode coupled' would refer to a phase splitter that has a shared, unbypassed, cathode resistor for both V1A & V1B, with the grid of V1B (at least AC) grounded. Also know as a Long Tailed phase inverter. That's NOT what's happening here at all...

Roscoe