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What can i do with this Solid State Organ Amp

Started by Slam, February 16, 2010, 09:54:33 PM

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Slam

I have been picking up these unwanted organs for the speakers and now i have a shelf full of different amps and i figure this could be a great learning tool. I'm thinking that it could be a mono block amp for home audio or a simple guitar amp. I am pretty sure that the RF jack is an input. I'm not sure how to treat the 4 wires going to the connector. The gray wire runs off the CB and is marked amp out. The black wire is a ground. and the red and blue wires run to different large resistors. How would i hook up a simple tone and volume? I could use some general knowledge of what i have here.  
 Now i know this probably won't be a preferred design. But i'm hoping it will help me to start understanding the basics.
Anyone willing to help me put these to good use? These organs are real easy to find for free if you have the man power to move them.

Mike

J M Fahey

Hi slam.
If the amps work (I bet most of them do) use them as-is.
Obviously you already have a matching speaker ;)
The RCA jack is the input, on the multiconnector Black is ground, Grey goes to the speaker + connector, Red and Blue must power the organ board.
Measure voltage to ground on all 3 wires, also on the main capacitor where those 2 big diodes go.
Maybe you can use some of those power wires to feed your preamp.
You can build a Polytone (Google images) type amplifier, with the power chassis in the bottom and the preamp on a top cutout.

Slam

#2
Thanks for the reply. Of course it is a RCA jack and not a RF jack :-[. I would like to keep it simple and you just gave me enough info to do a test run. This wasn't the main amp in this organ, i'm not sure what it powered but the main amp is  much larger and stereo. The speakers i pulled from this old Lowrey were 2-12 inch CTS with large alnico mags, 1- 6 x 9 CTS in the Leslie unit, and 1- 15 x 4 heavy Jensen horn. Definitely a good score.
 I'll pass a signal through this amp and report back 1st chance.

Slam

OK, I did a test run and hooked up the speaker + to the gray wire and - to the black. With the preamp out going to the RCA input. It passed the signal at a good volume but was pulsating. Is it possible that this is a tremolo amp? Something doesn't seem right . I have another amp that looks similar to this one only stereo. I'll try a test with that one and see what happens.