Amp crackling...troubleshooting tips?

[baba]

So I snagged an Ampeg BA115 off of CL for cheap. Of course, I now know why it was cheap...

It's nice and clean at low volumes, but when I crank it up there is a crackling that occurs. Almost like you get with a bad cable. It only happens when loud and some frequencies seem to produce it more than others.

My first thought is the input jack so I'll try swapping the 0db jack which I'm using with the -16db(?or so) jack to see if the trouble stays. I'm assuming it's not a blown driver because I've had several and they either stop working or distort terribly...they didn't crackle.

Any other ideas what could cause this?

 

[T-Bird]

Hi.

Don't know that particular amp, but if there's a FX-loop, insert a patch cable there. If the problem goes away, it's the oxidized jack-switch contacts that need cleaning. (or You leave the patch cord there)

Regards
Sam

 

[baba]

Hi.

Don't know that particular amp, but if there's a FX-loop, insert a patch cable there. If the problem goes away, it's the oxidized jack-switch contacts that need cleaning. (or You leave the patch cord there)

Regards
Sam

Great suggestion! No fx loop, but it does have an RCA in for CD/tape/etc. I'll crank some tunes through it and see what happens. Much easier than opening up, swapping input jacks, and soldering.

THANKS!

 

[big stubby]

I just got my BA 115 back from the shop for the SECOND time in 7 months. First time I had the same problem as you and it was loose soldering connections. This time they re-glued my speaker and mounts. I wouldn't mind so much if I played alot, but I don't. So tommorrow I'm trading this thing in for a Fender Bassman 250/210. And the reason you got it cheap is because it's a piece of crap

 

[jeromebass]

You may just be turning it up louder than it can handle. This is the case alot of times if it cracks more with lower notes.

 

[baba]

You may just be turning it up louder than it can handle. This is the case alot of times if it cracks more with lower notes.

Well I've heard many pushed/overdriven speakers and they distort more than crackle. This is very brittle crackling, like a flakey cable sounds.

 

[baba]

And the reason you got it cheap is because it's a piece of crap

I have a BA112 as a practice amp under my computer for learning new covers, and it's been great. Both of them are USA made, not sure if the new Chinese models are equal in reliability.

 

[baba]

First time I had the same problem as you and it was loose soldering connections.

In case I have to go down this road, do you know where the soldering points were? Input jack? Other?

 

[big stubby]

The place that fixed it, re did every connection.