Scratchy gain knob

[big_black]

The gain knob on my Crate amp is pretty scratchy, I'm wondering how I can clean the pot without killing myself. Can I use contact cleaner if the amp is unplugged?

I also have noticed the reverb cause a huge amount of noise when I turn it up. The reverb is not very noticeable either. What can this mean, and what are my options?

As you can tell, I'm pretty amp-dumb, so any help would be greatly appreciated. Thanks.

[DWVINKY]

Re: Scratchy gain knob

Contact cleaner is fine to use. Its non conductive, so you shouldn't have to worry about any shock hazards. As far as the reverb problem, it sounds like you have a bad reverb tank.

[big_black]

Re: Scratchy gain knob

How do I find one that will fit?

Apologies for my cluelessness...

[Gearjoneser]

Re: Scratchy gain knob

Take the chassis out of the cab, unplugged of course, and soak it with contact cleaner. If you don't have contact cleaner......well, I've used regular rubbing alcohol with good results. I just pour it into every crevice of the pot, and turn the knobs back and forth about a hundred times. It'll work.

Check to see if any preamp tubes are drivers for the reverb, and put fresh ones in. If the reverb isn't driven by a tube, it's either a bad component, a bad pot, or a bad reverb tank.

[big_black]

Re: Scratchy gain knob

I found out one of the preamp tubes does indeed drive the reverb. I suspect the tubes are going because it's got that "wet blanket" sound when the amp is clean. I'll change all the Tubes. Thanks!