1940s RCA amp

[johnny7]

I came across an old RCA film projector and pulled this little tube amp out. It appears to be about 20 watts. The question is what shall I use it for?
What is the feasibility of converting it into a mic pre?



J

[Snarl 12/8]

What would you use a 20 watt mic pre for? I'd go guitar amp with it.

[emrr]

It's probably cathode biased, and more like 8-10W. Agreed, guitar amp. Not a good piece to consider for preamp use, but you can stick any old mic to grid transformer on the front end, load the output transformer resistively, and feed that to a recorder and find out. Practically not a mod at all.

[Darlington Pair]

I don't see an output transformer. Do you still have the projector, it's most likely mounted to the speaker because it's a field coil speaker.

Yeah, I'd say amp, I bet keys sound great through that thing too.

[emrr]

I think it's behind the 6L6's, you can see the some of the leads on the bottom shot.

[Darlington Pair]

I think it's behind the 6L6's, you can see the some of the leads on the bottom shot.

You might be right, I guess every time I see a four pin speaker jack I automatically think field coil, I didn't look for the leads coming through the chassis.