Peavey Ultra Plus 120 Head Chassis

[misterc57]

Trying to get the output board out of this chassis to replace a resistor. It is not coming out. Are the tube retainer rivets holding the board in place? If so I am ready to solder the resistor on the back side of the board.

I also need to replace the 3 way resonance switch. Anywhere to order this besides Peavey? This is one of those parts where the shipping costs more than the part and I cannot think of anything else to order from Peavey to offset the shipping fee.

Thank you. MarkO

[The Dude]

Yes, the rivets hold in the board. I usually unsolder the resistor, shake it out, and install the new resistor on the opposite side. You should be able to get the switch from several vendors- try Mouser. It looks like a fairly common microswitch. Otherwise, call Peavey and see if you can get the exact part.

[g1]

Yes, push the old resistor out and mount the new one on the trace side.
Some Peavey's you have to drill out the rivets and replace them with rivets or screws & nuts.
I think that C&K switch should be available from somewhere like digikey or mouser, but others here may know if it is custom made for Peavey.

edit: Or... what he said ^^^^^.

[Enzo]

What else to order from Peavey? If all I need it a $2 switch, I might add on a couple tubes. They are not outrageous, and I can always use a fresh 12AX7 or even a pair of 6L6.

I agree with the above guys. If I need to replace a screen resistor on that board, I unsolder it, poke it through the holes and fish it out. Then solder the new on onto the solder side that is facing me. No rivets to drill.


In the event I ever really have to remove that board, we drill out the eight rivets (1/8" drill), Then reinstall the board with fresh rivets. Any hardware store carries pop rivets and the rivet gun.

[misterc57]

I did not know Peavey sold tubes, good suggestion!

Thank you everyone!

[misterc57]

Replaced R200 up in smoke

So I replaced the resistor, turned on the amp (in standby mode) and poof, another burnt up R200.

Background story; Just got this amp, it had one dead output tube which I replaced. Not sure what position it was in. The amp was up and running, and playing, and I noticed that one of the tubes was red plating. That is when I discovered that R200 was open, which I just replaced, and then, up in smoke.

Schematic shows that R200 and R75 share the same feed, R75 is okay, so I would guess that side of the circuit is okay. The only thing left is the tube socket.

Any suggestions on what to look for?

Thank you!

Schematic attached...

Ultra Plus.pdf

[g1]

Is the new tube at the socket connected to R200 ?

[misterc57]

Yes the new tube is connected to R200. The one that was red plating before I replaced R200.

[g1]

It may be a bad new tube that is taking out the resistor. Do you have another to try?
Or try just using just the one tube that never red-plated, in the R200 socket (after you replace R200 again). Running on one tube is ok for test purposes.

[The Dude]

Or, just leave the tube out of that socket all together and see if the resistor still gets hot.

[misterc57]

So it looks like the resistor I put in was shorting, perhaps to the adjacent jumper wire. New R200 is in, amp is working, no more red plating!

Thank you all for the help!