RCA Bridging Level Control

[dmp]

Does anyone know the specifications for this variable pad? It is listed for level control ahead of the input transformer on BA series preamps.
Has three resistors and a dual pot (or a single pot), possibly with a switch on the back.

This thread has an interesting discussion on variable U pad, which I think this RCA is.
The JLM variable pad is a dual 1k pot with a single 100 ohm resistor

 

[radardoug]

Thats probably a T pad. See the input on a UREI 1176 for reference.

 

[emrr]

Not a T. Variable U. It’s on several schematics, maybe ba-1. Common design used by many companies.

 

[dmp]

Found it in the tech docs. Thanks

 

[emrr]

That’s it. There are variations in parts values over the years.