I picked this up yesterday with a problem. Very low volume, what I would regards as around 1w. Marked on the chassis as August 98. I contacted the distributor here Music Link Australia, for a copy of the schematic (which is what Peavey advised) but they won't supply one to an amateur. Service technicians only. Would anyone please have a schematic for this?
Welcome to the forum :tu:
Strange that Peavey advised you to contact that distributor and then getting the run around. Perhaps in Australia there are different policies for service repair than here in the US. I know that if you contact Peavey directly, here in the US, they will support just about anyone. I have a couple of schematics. One is from 1995 so here it is. Perhaps Peavey will email them to you?
You may not even need a schematic to get started trying to troubleshoot. For example, there are effects send and return jacks on that model of amp. Those jacks can cause volume type issues if the contacts in the jack become dirty over time. You can insert a guitar cable from the Send to the Return jack to test if that makes the sound return to full volume. The send jack can be used to route the preamp signal to another amp to test if the preamp is working correctly. Also, the return jack can be used to test if the power amp is working by sending a line signal from another amp(or an mp3 player).
One other thought is to apply signal to the amp and thump on top of it with your fist. If the amp reacts to the thumps then there could be intermittent connection(something loose inside).
Thanks DrGonz78 for the schematic. Yes, I don't know if it is really a safety issue they are concerned about "We don't advise consumers working on our goods as they contain lethal voltages" or if they just find that a convenient excuse. Thanks for the tips on isolating the pre and power etc., I will try that tomorrow and see what I can do with the schematic at hand.
I'm not a very knowledgeable electronics person, but I can pick things up reasonably easy, have built a small tube amp etc.
Well I couldn't have asked for a cheaper or easier repair. I plugged in a patch cable between FX Send and Return and voila, good volume. I then took out the patch cable and no change. One of the jacks must have been stuck open, routing the signal away from the inboard path.
There are a couple of little things to fix on it, nut and washer on FX Return jack, new 1/4" plug for the remote switch, but for $50AUD plus $20 in fuel and tolls to pick it up it's been a great investment.
Good to hear you got the amp all working :dbtu:
Probably the amp sat for while or at least nobody used the send/effects jacks for while. Sometimes all you have to do is plug in the jack to wake it up and knock off some of the dirt. Still for good measure spray some contact cleaner into the jack and then push a plug in and out a few times. That ought to do it.
Save yourself all the pain of replacement of FX return switch just leave a short jumper cord permanently looped and it will never cause an issue :dbtu:
Phil.
Seems a common problem on a lot of the inexpensive Peavey, and Fender amps. I keep some jacks in my spares box, and if the circuit board has to come out, it gets new jacks! I did clean a few, with a burnishing tool, (they will came apart easily), but I don't think it's worth the effort.
Or squirt some cleaner in ther and work it in and out.
This happens to every brand of amplifier that has loop jacks.