A friend gave me an old Wurlitzer organ. The rotating speaker assembly was gone (bummer) but everything else was there. I've scavenged some tubes and speakers.

Three questions:
1) the speakers are 1962 Jensen C12r. One is reconed the other original. Any opinion on using these speakers in a guitar amp? Are they worth keeping for a project?

2) while I got seven nice 12ax7 tubes most of what was in there are 12fq8 tubes. I believe they are in the oscillator circuits for making the different notes. I'm not sure if they are usable in a preamp or not. They're very different in operating specs from the 12ax7. Anyone have a circuit suggestion for use with the 12fq7s?

3) the power transformer wires seem blackened near where they come out of the transformer. I don't think it caught fire as there are no electro-poopstains on nearby chassis or components. It may be paint but I can't tell. As long as it tests correctly (no shorts or opens in the windings), it should be fine, right?

mark123,
re: 3) input wires would carry the max current and may darken, also sometimes there is extra insulating varnish which can be darker than thinner coats. If it tests good then time for a no load smoke test with a low amperage fuse in the supply line. Hope you have the specs for the secondary voltage which if good would let you know there are no internal turn-to-turn shorts.

As far as the 12FQ8's, you could always build a Valvelitzer.

quote:

Originally posted by sig operator:
mark123,
re: 3) input wires would carry the max current and may darken, also sometimes there is extra insulating varnish which can be darker than thinner coats. If it tests good then time for a no load smoke test with a low amperage fuse in the supply line. Hope you have the specs for the secondary voltage which if good would let you know there are no internal turn-to-turn shorts.

Thanks for the info!

quote:

Originally posted by FiveFiveSixFan:
As far as the 12FQ8's, you could always build a Valvelitzer.

Ha! Nifty. I can build about 30 of them with all these tubes!

quote:

Ha! Nifty. I can build about 30 of them with all these tubes!

People would probably buy them right up, too. It's a simple circuit but a strange tube. Having four plates in a dual triode is rather strange, although in this circuit, they end up effectively having only two.

The Jensen C12R speakers were used in Gibson and Fender guitar amps of that era.

Mark. Those speakers are great for bluesharp.

Those Jensens are great guitar amp speakers.

I did want to build a 2x12 cabinet to go with my Marshall combo. Looks like I've got the speakers for it.

https://www.jensentone.com/vintage-ceramic/c12r

Here is Jensen's page on the C12R. It is a ceramic magnet speaker. I kind of like them better than the alnico magnet version. Ceramic is a little cleaner sounding until it clips. Alnico does clip a little more smoothly when you push it really hard. It is a subtle difference.