Projector 6V6 Tube Amp rats nest p2p

[alvarez]

I have a point to point rats nest 6v6 tube amp that was pulled from an RCA projector that has incredible tone! I have had people freak out over the guitar tone this thing has especially when it is turned up. There are tubes powered and I dont think there is any way they are all being used for the amps sound. I have read some of the tubes were used for different functions in the RCA PJ.

I have built tons of stompboxes and DiY amplifiers before so I am no stranger to getting my hands dirty and testing things. Where would I start at to find out what is essential and what isn't?

I have a buncha pics I took in case someone was familiar with the PJ amp that I have and might know some info on it off the top of their head.

that speaker is amazing sounding.

rest of pics at Index of /misc/6v6

any help is greatly appreciated!

[bob91343]

That's not a rat's nest; that's how everything was built back then. Notice every solder joint has a dot of red paint which indicates it has been inspected.

Your pictures are so big I can't get a perspective. What is the tube complement? And what is your question?

[alvarez]

Originally Posted by bob91343

That's not a rat's nest; that's how everything was built back then. Notice every solder joint has a dot of red paint which indicates it has been inspected.

Your pictures are so big I can't get a perspective. What is the tube complement? And what is your question?

LOL i wasn't calling it a rats nest thats just what they used to call the older style of point to point.

I am trying to find out which tubes are being used etc. Basically find out what makes the thing sound sooooo good. the tubes are 1 5Y3GT, 3 6v6GT, 1 6SL7GT, 6J5, and 1 6J7

[taj]

Originally Posted by alvarez

LOL i wasn't calling it a rats nest thats just what they used to call the older style of point to point.

I am trying to find out which tubes are being used etc. Basically find out what makes the thing sound sooooo good. the tubes are 1 5Y3GT, 3 6v6GT, 1 6SL7GT, 6J5, and 1 6J7

The only way you'll know is to find or create a schematic. Start tracing those wires.

..Todd

[TheGimp]

I only see two transformers, one for power (black with end bells) and one probably output transformer (open frame). With three 6V6s it is interesting. SE with three in parallel? I only see four wires from the potential OPT.

[bob91343]

Probably three in parallel. But since it's for a projector, maybe one was used for some other function. They could get enough power without building a phase inverter or a tapped transformer.

[Frank Berry]

You can always pull the tubes ... one at a time ... and see what happens.
It should be easy to see if all three 6V6 tubes are in parallel. It's possible that one of the tubes is a voltage regulator or, perhaps, connected to the exciter lamp if the projector used optical sound.
I love these old amplifiers. Many of them did a spectacular job.

[Yvesm]

RCA engineers were serious guys who probably never had the silly idea of using three 6V6 in parallel
More probably a PP.
Remains to find what job did the third ?

Yves.

[Frank Berry]

Originally Posted by Yvesm

RCA engineers were serious guys who probably never had the silly idea of using three 6V6 in parallel
More probably a PP.
Remains to find what job did the third ?

Yves.

I agree. The amp would produce much more power in a PP configuration.
I'll bet it's a voltage regulator.

[Wavebourn]

Originally Posted by Yvesm

RCA engineers were serious guys who probably never had the silly idea of using three 6V6 in parallel
More probably a PP.
Remains to find what job did the third ?

here is the answer: NJ7P Tube Database Search