Question about the Hoffman 1 channel AB763

[coreysan]

I'm working on a AB763 for the Fender Super Reverb kit, and also comparing it to the Hoffman AB763 one and two channel
designs (which are really really nice, I might add!).

So far the one thing I don't understand is that on the Hoffman schematic, the
preamp signal going to the PI has a 47k resistor (r30) going to ground.

What does that do?

[sluckey]

It simulates the loading of the AB763 Intensity pot.

Hoffman's AB763 is not a true AB763. It uses an earlier version bias modulating tremolo. Look at the schematics to compare.

[EL34]

What Sluckey said

If you look at the original AB763 there is a 50kra intentsity pot connected to that same point and the bottom end of the pot is connected to ground
I am replacing the 50kra post with a 47k resistor

[coreysan]

Ah yes - makes perfect sense. If I had read through the entire schematic...
I'm sorry!