short or is it the speakers

[ewmtele]

i have a 1993 fender ultimate chorus. I ordered it off ebay. I already knew the speakers were damaged when I had ordered them. I have the amp now. There are some problems I noticed about the amp. when I play with the overdrive and other channels real loud the speakers interupt with feedback and popping. It is repetitive and sometimes heard when I cut the amp on. I figured it was the speakers since they have holes in the tolex. Also i opened the reverb pan and found that it was damaged. now when i tap the back part of the control panel it brings back that repetitive feedback and popping. Someone please help me. I really want to know if this is something I can fix.

[Brad1]

when I play with the overdrive and other channels real loud the speakers interupt with feedback and popping.

I figured it was the speakers since they have holes in the tolex.

Also i opened the reverb pan and found that it was damaged. now when i tap the back part of the control panel it brings back that repetitive feedback and popping.

Second line first: Speakers don't have tolex. Tolex is the covering of the cabinet.

First line: Holes in the paper speaker cones won't prevent them from working, somewhat. If the surrounds on the speakers are gone, then it may pop, because the cone isn't centered, and could be rubbing and grabbing against the magnet gap. Neither of these should really cause "feedback". Feedback is caused by having guitar pickups to close to a loud amp speaker. The signal is amplified, and picked back up by the pickups, the amplified more, etc. It's "feeding it back" through a non-stop looped cycle.

If it's feeding back with no guitar attached, it could be some kind of a circuit problem. Are you sure "feedback" is the correct description?

Third line: Unplug the reverb tank, and see if anything changes. You say it's damaged. How so? What do you see that led you to that conclusion? Are the springs disconnected?

Does it work fine at some settings, but starts wigging at certain others? "When I play the overdrive and other channels....". That really says nothing.

Plug the thing into a different speaker, or cab. Does anything change?

You say you knew the speakers were toast. Did the seller mention the other problems? I hope you didn't pay much for something in that condition, since you know it'll cost between $100-200 for acceptable speakers for the thing. If there's more wrong, it'll likely cost more. Those amps are barely worth ~$300 in good condition, used. If there's more wrong, and the seller didn't mention it, I'd be wanting my hard-earned money back to buy something decent.

Brad1

[Rockn]

Cleaning?

It could also be any number of things aside from the speaker. Unplug it and open it up to see if there are any large capacitors that are leaking or bulging. Do not touch anything inside even with the power off, just observe and report back. I had a Peavey Chorus that was acting up and cleaned all of the pots with Deoxit and cleaned the circuit boards with alcohol and a stiff brush and it was like new after that. Discharge the power caps before doing anything. Who knows how many beers have been spilled in the back over the years.

[Enzo]

My very first thought is the large main filter caps need resoldering - a common problem on solid state Fender amps.

[monsteranus]

I have one of these right now with a really bad hum along with a sort of jews harp sound when plucking a strings.

I checked the filter caps and one had a broken lead. I installed a cap of the same value I had on hand. The hum is gone as well as the crazy jews harp noise.

Enzo is right about the caps being a common problem. They need a better support method since those are tall on the board. This amp had turned over and the caps may not have handled the shock load very well.