[sdiy] Help understanding the UREI 565T

[Florian Anwander]

Hello,

can someone explain me a detail in the bandpass/notch circuit of the 
Urei 565T

http://www.jblproservice.com/pdf/Vintage%20JBL-UREI%20Electronics/UREI-565T.pdf

It is the potentiometer R35 called "Balance" on page 14  (or R62 on page 
15 resp.). I could try a 565 yesterday for a short time, but I didn't 
get any audible response from this potentiometer. Maybe the 565, I was 
trying, is broken. But what should this potentiometer do really?

Florian