Unique power transformer from RCA stereo

[bastardbus]

I picked up a RCA 3 channel stereo unit yesterday. The changer was yanked and the cabinet was so-so shape. It had what looked like a decent tube amp upon quick look see. It was $15 so bought it. Here is what is there amp wise.

The amp is 3 channels, a center 12" for bass frequency and a left and right channels which are 6-9s for mids and two tweeters. The three channels are each powered by a single ended 6BQ5 so there is three of them. There is four 6CG7s for pre-amps. It has 3 really nice SE out put transformers.

The one thing I have not seen before is it has an odd power transformer.
Primary is
117@1a
Secondary #1
130@.650a
Secondary #2
6.3@4.8a

There is two diodes that seem to be set up in a voltage doubler circuit and gives you 320 on first filter and 280 on the plates of the 6BQ5s. I wanted to try using this transformer for some sort of build. My assumption is I have to use the same voltage doubler circuit in the amp already and probably stick with 6BQ5s because of the b+ voltages.

I have not seen a set up like this before so wanted to double check with folks on here if this would be an ok PT and set up to use to build something with. It is a nice big PT and I hate to see it go to waste.

Thanks
T

[martin manning]

Sounds good to me. With 130*0.65 = 84.5VA secondary you should be able to power 4x EL84 in push pull with that PT.

[Phil_S]

FWIW, I agree with Martin. Rock n roll with that PT. 130v @650mA is plenty to work with. A doubler will give you 2.8x...that's 365-ish @ 325mA by my calculation. Even if it turns out to be 320V, that is still OK. 4.8A on the filaments, you can do a lot. You are more or less in a sweet spot, where you can use a PP pair of just about any power tube you want. With the doubler, you don't have to save anything for a rectifier tube. Nice find!

$15? A real bargain!

[bastardbus]

Great to know this PT will be usable with that voltage doubler set up.

Thanks!
T