Damaged Solid State Guitar Amp Question.

[mr_deadmaxxx]

A solid state guitar amp was temporarily used as a bass amp. It used to be perfectly fine before but now the sound gets scratchy randomly until you set the knobs to a sweet spot.

Could anyone please tell me;

Which part of the circuit could have been damaged? Was it the speaker only? The amp IC?

I dont really have any deep ideas regarding frequency ranges of sound stuff but I knew using it as a bass amp was not a good idea.

Thanks for your replies.

[Jdansti]

There shouldn't be any reason that a bass guitar would damage a regular guitar amp.  Can you narrow it down by plugging into another speaker, or is it a combo?

Also, don't rule out the guitar, effects, cables, and that it might have been a coincidence that a bass was played through it and you have a problem that would have occurred anyway.

[mremic01]

The only thing playing a bass through a guitar amp can damage is the speaker. If it sounds 'scratchy', it could be that the bass frequencies made the cone move too much and the paper tore somewhere.

[tg509]

A solid state guitar amp was temporarily used as a bass amp. It used to be perfectly fine before but now the sound gets scratchy randomly until you set the knobs to a sweet spot.

I assume you've tried cleaning the pots?

[mr_deadmaxxx]

The only thing playing a bass through a guitar amp can damage is the speaker. If it sounds 'scratchy', it could be that the bass frequencies made the cone move too much and the paper tore somewhere.

so maybe i should replace the speaker? it's a combo amp.

[mremic01]

I wouldn't replace the speaker right away. Try to diagnose the problem. Look at the speaker to see if anything is torn. Try some contact cleaner on the pots. Make sure the speaker wire isn't touching the speaker, that can cause a buzzy scratchiness. Try hooking the amp up to an external cab and see if it still makes that noise. Once you figure out what the issue is, it should be an easy fix.

[mr_deadmaxxx]

it turned out speaker was okay. i think the knobs are the culprit cause every time i try to turn them, scratchy sound comes out.but not when i just leave them.

[Mustachio]

This is in the pictures section ?   

Its hard to diagnose from here , What has happened to me and another friends fender deluxe's from the early 90s was the filter caps went bad after 20 years. Bass Freq's would cause the caps to vibrate and cause this horrible scratching popping overtone. Not sure if that's what your hearing or not.

When it actually happened to my amp it was when I was doing stupid things like running a tube preamp in the fx loop with a rack multi fx using a Leslie simulator and the lows where to much and caused the caps to shake themselves to death which they musta been on their last leg.

First thing would be to take it apart clean the pots and make sure all the connections are good. If you want while its open use a wooden stick like a chop stick or a shishkabob skewer and try to tap/move the big scary filter caps  (while holding one hand behind your back for safety ) with the amp on and a signal passing. if you can trigger the sound from moving a capacitor it might be bad or have a bad solder joint from all the shakey bass it just went thru. I guess bass freqs are gonna rattle things around more and thats why Im mentioning this since you played a bass thru it for a bit.

Hopefully its just scratchy pots and you wont have to worry about soldering any big caps or anything. If you do, check them with a volt meter first see if they need to get drained using a resistor between two alligator clips(insulated) and drain it to ground like the chassis. Maybe tape one end to that chop stick and use it as a probe. I remember reading something about solid state amps having a set of power resistors that auto drain the caps as soon as the amps turned off, but I would still be cautious with large capacitors and double check everything. (their deadly for real)

The 2 amps Ive done this to where fenders one a deluxe '85 and the other a deluxe 112. Good luck and be safe!

[mr_deadmaxxx]

hey thanks man. i was about to replace all pots. it's a good thing i never had started yet.

so the big filter caps could be the other culprit? how about the small ceramic ones? there's many of them so i hope it didn't damage them too.

[Fender3D]

you'd better try spray contact cleaner in your pots, before replacing them... 

BTW
hit your small ceramics with a toothpick... you know the smaller the capacitor the smaller the stick....