How to test a Bi-Directional Triode Thyristor

[Tom.G]

Referring to posts #146 (by Jim) & #147 (by Tom) above, the speaker current feedback seems to be explained here:

Particularly in the graphs at the bottom of post #5.
Small Amp Project (Tube/power stage info needed)

 

[jim hardy]

Good eye Tom !

I hadn't caught that in the Carver,
i only assumed they used current just to invoke a power limit.

But it's right there on the block diagrams , page 8 of service manual.
And specification page says

Damping Factor Greater than 9 - Tube Characteristics

Thanks !