sa-232 rebuild has begun

[SET12]

The circuit we used was from a Pilot Integrated Amp I don't remember the model the 232 is from a console.

I have both amplifiers and I can tell you the circuit with the 12AX7 only kicks the 12AU7-12AX7 circuits butt IMO! The 12AU7 circuit is thin sounding in contrast and it stands to reason for double the feedback that it has! Theres just way to much gain using both 12AX7 and the 12AU7. But maybe thats what you like! I know I don't care for thin sounding amplification myself.
I also can tell you that the 1db increments of feedback are audible!

With just the 12AX7 the amp has less than 500mv in for full output.

 

[wa2ise]

there appear to be four ground lugs for each el84 socket. there should be no difference which i hook up to, correct (if i want make a distance shorter and more direct...cleaner, in essence)?

I'd be careful to use the same lug for the replacement part. Else you could induce hum ground loops and feedback problems. The orginal manufacturer designer may have had to solve such, and told production where to wire what to avoid problems. The problems come from the way currents would flow thru the chassis, and the fact that the chassis has some resistance, and thus voltage drops.

 

[TheRed1]

Here are some Pilot ads I ran across:

From Feb. & June 1960:

From Dec. 1964: