PV solid state amp crackles when you adjust gain.

[Herm]

I have a Peavey trans tube 300watt head that when you adjust either gain knob it crackles. At first I thought it was the pot, but since it is happening only on the two gain knobs I believe it may be something else.

[gbono]

check for DC - leaky cap somewhere?

[nashvillebill]

Welll, if it only happens on those two gain knobs, then it could be...the pots the two gain knobs are attached to? Try spraying a tad of Deoxit into them (you will likely have to disassemble the amp partially to get good access to the bodies of the pots). If that seems unclear, google "how to use Deoxit"

It's also possible there's a cold solder joint on one or the other pot (or even somewhere else), and turning the knob is tensioning the solder joint just enough to make and break it.

The DC leaky cap is a possibility, but my first guess on a relatively new SS amp would be noisy pots.

[R.G.]

Every time I hear the words "crackle" and "control" or "pot", I have this Pavlovian response and drool "DC on a pot!"

It's not the only way to get crackle, but it *is* a good one, and very common. DC on a pot shows up any flaws the pot might have; it shows up flaws that would be inaudible with only AC on the pot.

Look for DC on the controls that crackle. If there's none, go elsewhere. But if there is, find out what's feeding it DC.

And no, crackle is never OK.

[Chuck H]

crackle is never OK.

Someone doesn't like a nice fire or rice crispy treats.

Seriously though, DC on the pot is the most likely cause. Bad transistors or leaky cpacitors are usually the culprit. If you find DC on the pot then just trace it backwards in the circuits signal path. Testing for the same DC volts. If you find that there is higher DC behind a capacitor in the path then it;s likely that capacitor is at fault. If you trace back to a transistor then it's likely that transistor is at fault.

[Enzo]

I guess I will have to think about it. To me, dirty controls seems way more likely than DC on the pots. DC is second on my list. A few seconds of squirt tells that story.

[Herm]

guess I was wrong..

it was dirty pots. I cleaned all of them and now i have a brand new amp. That's what I get for overthinking. Thanks to everyone for your guidance.

[Gtr_tech]

DC on a pot sounds more like a scraping sound to me, not a crackle.

[Enzo]

Oh I am with you on terms having specific connotations. But in the large world of the unwashed masses, I hear white noise sometimes described as "hum," so I never assume. The complaint boils down to noise of some sort.

[MikeH]

And no, crackle is never OK.

I heard Zach was going to change the labeling on the SHO to read "Crackle is simply something we all must deal with on occasion, from time to time". I still don't know how they're going to fit all of that on the box.