Peavy classic 30 issues

12Pack

Dyslexic b00n
Any thoughts on this?

Playing through my Classic 30 head and using the footswitch to play the clean and dirty channel. Randomly the dirty channel volume either gets louder or softer. Its not consistant but would have issues if ever playing live.

Thinking perhaps a re-tube as the ones in there are probably 10+ years old.

Thoughts?
 
Yes absolutely re-tube and bias. Thats a power tube symptom. That's the first sign when my amp needs a retube. I would try to not play it much until you do it. On the chance that a tube blows it could take a screen(grid) resistor with it...then it going to the shop for sure.
 
Thanks guys. Actually found a Peavy forum after posting this and some past people had some problems. One guys just sprayed all the tube sockets with cleaner and claimed thst solved his problem. Ordering tubes probably today as I think starting from a new set (Power and Preamp) will have me worry less then having it just sprayed with electronics cleaner.

There are some great you tube videos as well for the fixing classic 30s as well.
 
Thanks guys. Actually found a Peavy forum after posting this and some past people had some problems. One guys just sprayed all the tube sockets with cleaner and claimed thst solved his problem. Ordering tubes probably today as I think starting from a new set (Power and Preamp) will have me worry less then having it just sprayed with electronics cleaner.

There are some great you tube videos as well for the fixing classic 30s as well.
I'm sure you already know, Preamp tubes can and often do last years....it certainly won't hurt to change them along with the power tubes but it probably isn't necessary.
 
I'm sure you already know, Preamp tubes can and often do last years....it certainly won't hurt to change them along with the power tubes but it probably isn't necessary.

Yes. I just orderd the three new 12Ax7 for the preamp. The original owner had a Fender mixed with 2 Solveys and all the power tubes were Solveys.

Just ordered new ones across the board. Now at least I will have spares for both power and pre if I decide to gig with this amp. It has the coolest tone and I enjoy it very much.

Still working with the Boss Katana100/ 2x12 as a possible gigging amp too. Between getting the 40 songs down for the wedding gig on the 11th I havent even loaded the SW for that amp yet. Plus all the foot switches for said Katana are back ordered.
 
Start with tubes. Like MESA el84 amps (actually all MESA amps), the c30 is fixed bias but doesn't have an adjustment pot (a common mod). I would have the bias checked to ensure it's not running too hot after retubing.

I believe the c30 had an issue with jumper wires connecting the boards that would require the solder to be reflowed. You may wish to explore that if the issue continues after a retube. Also, if the amp is that old, I'd consider new filter caps.
 
Start with tubes. Like MESA el84 amps (actually all MESA amps), the c30 is fixed bias but doesn't have an adjustment pot (a common mod). I would have the bias checked to ensure it's not running too hot after retubing.

I believe the c30 had an issue with jumper wires connecting the boards that would require the solder to be reflowed. You may wish to explore that if the issue continues after a retube. Also, if the amp is that old, I'd consider new filter caps.


One of the You Tube videos I saw the Classic 30 had a VERY bad hum in it. It was the Filter Caps - one in particular. The repair guy replaced all of them and it looked like a real PITA as all the capacitors were glued down to the board.

The video showed the connector wires - bent at a 90 degree angle from one PCB to the next. Just the idea of having to take the boards out looks like a situation asking for trouble. Hopefully I won't have to go down that path.
 
One of the You Tube videos I saw the Classic 30 had a VERY bad hum in it. It was the Filter Caps - one in particular. The repair guy replaced all of them and it looked like a real PITA as all the capacitors were glued down to the board.

The video showed the connector wires - bent at a 90 degree angle from one PCB to the next. Just the idea of having to take the boards out looks like a situation asking for trouble. Hopefully I won't have to go down that path.

I've heard the C30s are a PITA to work on because of how the two PCBs mate, but why the hell would they glue the filter caps to the board? Makes no sense to me. I picked up a C30 last year and haven't had to open it up yet. Not looking forward to that at all.
 
I believe the c30 had an issue with jumper wires connecting the boards that would require the solder to be reflowed. You may wish to explore that if the issue continues after a retube. Also, if the amp is that old, I'd consider new filter caps.

I had a C30 that kept going dead on me. The jumper wires were the problem. I had it repaired under warranty. Since that amp ran very hot, I purchased a small fan just for the amp to keep it cool.

Upgrading the speaker was a PITA. The amp chassis had to come out for a speaker change.

Good sounding amp when working but I'm glad I've moved on from it.
 
Glued filter caps aren't much of a problem. I replaced them in my C50 and I think they were glued. I believe it was hot glue and it pretty much peeled off.
 
PVC305.jpg



The famous jumper wires. It's almost a foldable PCB board....
 
Glued filter caps aren't much of a problem. I replaced them in my C50 and I think they were glued. I believe it was hot glue and it pretty much peeled off.

Yeah, glued caps shouldn't be an issue, with all of the heat in tube amps, by the time you need to change the caps, the glue is pretty dead and will peel off like yours did.
 
Yikes, what an awful design!
Yes and no. There's the obvious highly-probable failure point with those jumpers, but if they're soldered correctly and the bracing (see that angle bracket on the bottom?) is secure, the connection should stay in tact. That said, road use would certainly test that design. On the positive side, that design let them squeeze the electronics into a much smaller space, allowing the amp cabinet to be smaller than it would be if everything was on one flat board. It's a trade-off, like all design challenges.
 
Yes and no. There's the obvious highly-probable failure point with those jumpers, but if they're soldered correctly and the bracing (see that angle bracket on the bottom?) is secure, the connection should stay in tact. That said, road use would certainly test that design. On the positive side, that design let them squeeze the electronics into a much smaller space, allowing the amp cabinet to be smaller than it would be if everything was on one flat board. It's a trade-off, like all design challenges.
Wouldn't ribbon cables be a little more robust? Maybe ribbon cables with plugs?
 
Wouldn't ribbon cables be a little more robust? Maybe ribbon cables with plugs?
Maybe. Ribbon cables have a tendency to work themselves loose with vibration though, and the connections can oxidize over time leading to intermittent connections...kinda like the old Nintendo game cartridges. Peavey probably thought this would stand up to road abuse better than ribbon cables. The flaw, IMO, is that they used somewhat rigid wire for the jumpers which adds extra strain to those connections. They should have used a more flexible, stranded wire.

From a manufacturing standpoint, it is a terrible design. That all had to be done by hand and was very labor-intensive, with a lot of opportunities for cold solder joints.
 
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