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Discussion Starter #1
Hey everyone.

I have a Peavey Express 112 Sheffield 65watt transtube SS amp.

Everything about it works fine. But when I turn my reverb knob its scratchy. The reverb still works, but I don't like the scratch/crackle sound. Is there a way to fix this? Perhaps just pull the knob off and clean around it? or would I have to dismantle the amp and take the knob out to clean it?

Thanks :)
 

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It's probably just a dirty pot. You can get some electronic contact cleaner, ideally you want the brand DeoxIT but I don't think there's any dealers in Canada. You want the cleaner to not leave a residue, and for it to also lubricate. I'd call Long & McQuade or something and ask what they use.

Take off the knob, and spray down the shaft, then rotate back and forth about 20 times, let it completely dry for a day and repeat if needed. You may have to take apart your amp, and actually get inside the pot. There's usually a little hole on the back of the pot casing to spray the cleaner in. If that doesn't fix it the pot may be worn.

I just got my amp head's pots cleaned at L&M and it only cost $16, which is about the cost of a can of cleaner.
 

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Discussion Starter #4
I think I actually have a can of contact cleaner kickin' around somewhere. I'll see if I can find it and try it out. Thanks :)
 

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I think I actually have a can of contact cleaner kickin' around somewhere. I'll see if I can find it and try it out. Thanks :)
I tried to use some Radio Shack brand Contact and Head Cleaner and it didn't work for me. I don't think it's a lubricant either because some of the knobs were sticking after.

I'll probably cave and by a can of DeoxIT even though it'll cost $20-30. It would last years so I guess it's not that bad.
 

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MG Chemicals makes a very good contact cleaner and you can get it through most electronics stores. You need to be careful on what type of lubricants it uses as sometimes it can add to the problem.
 

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MG Chemicals makes a very good contact cleaner and you can get it through most electronics stores. You need to be careful on what type of lubricants it uses as sometimes it can add to the problem.
Yeah, I have been using "Neutrol" for quite a while with good results
 

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Cool, I'll go grab a can tomorrow morning. Thanks guys. I'll let you know the results.
You may not have much luck trying to get some of the spray down the shaft to the innards of the control. It's designed not to allow this to happen! The last thing you want is for someone to spill something on a control on the outside of a panel and have it leak inside the controls. Besides, if you ever took a control apart you'd see that the leaked spray fluid would have to travel some ways at right angles to the shaft to reach the dirty resistance element and allow the wiper arm to agitate the fluid and cause cleaning.

Still, you can try! If it works then good for you!:smile:

The usual way is to open up the amp to get at the back of the control. In a Peavey they are likely mounted on the printed circuit board which may make things a bit of a PITA, compared to older amps where the control is mounted by itself to a panel, with wires making the connections.

Anyhow, you'll quickly see the control has 3 solder lugs coming out of it. As I said, they may solder directly to the board. You need to spray up between these terminals to wash the inside of the control. I've found that if I bend the last 1/2" of the plastic wand I can wedge it up from the circuit board and get the spray inside. Failing that, most amps use cheaper controls and you'll often see a small "dimple" in the metal rim that will allow access to the inside.

Once you get some spray inside you rotate the control back and forth to clean the element.

Just FYI

:food-smiley-004:
 
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