Peavey Studio 210

[kokain]

I have a Peavey Studio Chorus 210. I was playing really loud today. I stopped playing and a wall of feedback came up. I turned the volume down but the loud noise remained. Even with all of the pots turned total left and no cord plugged in, the noise is there. It sounds like feedback (not the high pitched feedback, but the lower smooth feedback) and a volume of 8. All of the caps are from the early 90's I suppose. I was going to start there. I'm not sure how to test anything, I will muck around until I get an answer. Please help me.

[olddawg]

I have a Peavey Studio Chorus 210. I was playing really loud today. I stopped playing and a wall of feedback came up. I turned the volume down but the loud noise remained. Even with all of the pots turned total left and no cord plugged in, the noise is there. It sounds like feedback (not the high pitched feedback, but the lower smooth feedback) and a volume of 8. All of the caps are from the early 90's I suppose. I was going to start there. I'm not sure how to test anything, I will muck around until I get an answer. Please help me.

By lower smooth feedback do you mean a loud 60 cycle hum? If so you may have shorted an output device and am hearing DC across the speaker. When you turn the amp on does th speaker cone push out or pull in? Your failure mode (playing load ten crapping out) would seem to indicate an output failure. I'm not familiar with the model without a schematic. It could be just a monoblock IC or discrete components. (It isn't a tube amp) Either way if you don't know some basic electronics you could complicate a simple repair and possibly hurt yourself by " mucking about until you get an answer." If you know how to use a multimeter see if you have DC from the positive terminal of your speaker to chassis ground. A lightbulb limiter would probably keep you from causing more damage.

[Gtr_tech]

I had one of those in a while back with a similar problem. Just a whiny noise and the chorus wasn't working as intended.....sounded like a flanger with the feedback maxed. Check to make sure the compander IC is getting the right supply voltages. A missing 15v supply was the culprit there due to a fractured trace. Check for bad op amps as well.

[kokain]

I have a DMM. How do I test opamps?

[kokain]

Loud humming problems

This sounds extreamly similar.

[kokain]

OK. So I guess no one likes me.

I ordered:

2 MJ15016G
2 MJ15015G
2 SLPX472M035A3P3
and some heat paste.

The transistors are on back order until the first of the year through Allied. I will post an update after the swap and re-assembly. I hope this fixes it. Next I can look forward to the 20 year old speakers to blow. Oh well.

[Gtr_tech]

Did you have DC at the output with no load attached?

[kokain]

Yes. I saw a lot of references to watching the speaker move. If it stays in one direction then it is DC. Mine did. It pushed out and stayed there.