debugging old peavey blues classic

[freakshow]

Hi ..

I've been looking around in the forum and haven't really been able to find any similar problems, so I hope there's someone out there who's able to help me with my problem

I have this rather old Peavy blues classic 30 with a 15" unit, and I really love the sound it has - But it doesn't work anymore

What happened was basicly, i started the amp, letting the tubes heat up, switch off standby and started playing - Not loud or anything. But after playing around 10-15 minutes the amp started to make the very loud puf noises, then i stopped playing and disabled all my fx pedals. Then I just tried playing a little with clean sound, and the amp made those sounds again, and I could see reflections of blue light on the wall behind the amp. So i quickly turned off the amp.

But now I can't get any sounds out of the amp at all, when i turn in on, the AC indicator bulb starts glowing, and i can see that all of the tubes are glowing like they would normally do. I've also looked at the speaker unit and it looks intact - no obvious cracks or anything like that..

Less than a month ago i got new tubes, and I've got them biased correctly - the new tubes are:

Tungsol 12ax7
Gold lion (Genalex) n709/el84
EA. ElectronTube MT84

So i would be extremely happy if any of you guys are able to help me debug it..

[Gtr_tech]

[QUOTE=freakshow;129794]Hi ..
with a 15" unit,
QUOTE]

Wow....impressive! Sorry.....you set that one up yerself

First off.....its a Classic 30 right? Careful there....you said "old" and "classic" in reference to a PV amp. There is a PV from the 70s thats called a "classic" but is a different amp from the 90s era Classic 30.

You had a pwr tube failure if you saw arcing. You'll likely find open screen resistor(s) on the shorted tube(s) and a blown B+ fuse.

[freakshow]

Yeah well .. The amp is all most as old as i am and its called blues classic

That aside, thanks for the advice .. I'll check it out asap

Do you know what causes this fault?

[Enzo]

Delta Blues? That is a CLassic 30 circuit with a 15" speaker. (also could be 2x10)

SOunds to me like one of your EL84 power tubes failed, and now the high voltage fuse inside the amp is also blown because of that.

[apgwheeler]

Others don't seem to understand that this amp is no longer made. It is NOT a delta blues. This is an old (early 90s) amp that sounded great night after night. It is 50 watts of power, tube, EL84s and 12AX7's; and Peavey discontinued this amp circa 1998. It is the "Peavey Blues Classic", and production stopped some time ago.

It sounds like a biasing problem or possible tube issue (although the tubes are new). I had 2, like a fool I sold one! Now I just have my original from '92.

These amps have a 15" speaker. Essentially the same wiring as a Classic 50, except a 15" instead of 4 10"s.

I urge you to hold on to this amp as the current "Peavey Delta Blues" cannot hold a candle to this amp's tone and power.

Bring it back to your tech, soon.

[freakshow]

I have delivered it at my guitar tech, and he is working on it right now..

But a took another look myself - All the tubes are glowing as they should, and as far as i could see some part of the curcuitry is fried, so i really hope it's just that.

And that i have my amp back soon

[Enzo]

Ah, it is a Classic 50 with a 1x15 combo cab.