RCA BC-3B Program Amp / Monitor Amp conversion

[beezer4]

Hey all,
I snagged a sled with the BC-3B program and monitor amps with output transformers from eBay. I'm thinking about converting them into mic preamps by adding switchable input pads and step-up input transformers. If I wanted to add a "gain" control, could I substitute a pot in place the resistor coming off the FB winding of the transformer? It's 2R12 on the program and 3R13 on the monitor amp.

Also open to perspective if mic preamp conversion is the best use for these.

Thanks!

 

[emrr]

They work fine as preamps, up to you if a 6W monitor amp is good use of power though. They are cool sounding speaker amps.

Honestly I’d be more into converting the PGM to a fully PP preamp, if i were just using the iron.

Yes on the NFB, within limits. Prob need a stop resistor limitation, possibly both ends of the throw

 

[Piedwagtail]

Myriad of options.
As Doug says - with an input transformer the phase splitter becomes optional and paralleled 12AU7 could be reconfigured into two PP stages .
The 6V6 could revised for 6SN7.... or rewired for triode
playing a bit fast and loose with output transformer spec in all cases but worth experimenting.