I have a Peavey Valveking (VK212) and don't really use it too much. When I do the clean and gain are on no more than 1 / 10 on the volume scale. I have never had it cranked.

A couple of days ago I turned it on to play for a while but when I selected gain it simply didn't have the gain it once had. It was a very slight gain and not crunchy/metal sounding at all (like it always used to be).

Any thoughts?

Almost definitely a preamp tube. Did you try different guitar through the amp?
Tastes like chicken, if chicken was a candy.
Yeah, I tried a couple of guitars through it with no luck and tried all of the knobs! I would say I play once every week or so, not very often. It is certainly not overuse...

If it is the preamp tube what's the fix... and the cost?

Thanks guys/gals...
Switch your preamp tubes around, one at a time. You have three, so swap the first one and the second one, then put them back. Then swap 1 and 3, and then put them back, then swap 2 and 3, and put them back. Any change in your sound during one of these swaps should tell you if its a preamp tube, and which one.

Use a process of elimination.

Swaps like this:

If swapping 1 and 2 = Change in amp's condition - then - swap 1 and 3 to find out if it's preamp tube 1 or 2. No change means it's tube 2. Another change means it's tube 1.

If swapping 1 and 2 = No Change - then it's tube 3. Swap tube 3 with tubes 1 or 2 to confirm.


It should be powered down and preferably unplugged (although not entirely necessary) before you start pulling tubes. Do this each time you swap.
Tastes like chicken, if chicken was a candy.
Last edited by ConfederateAxe at Nov 27, 2009,
They're the metal-cased tubes right? I've never played with tubes before... I can't screw up right? There's three of 'em.

I'll give it a try...
I can only get one tube out. The two closest to the back are lower down and I can't get a grip of them to pull them out. I guess I'll have to take it to a shop. Any idea of the cost for a preamp tube? Should I get three new ones?

If you get new preamp tubes they are only like 10-15 bucks each depending on what you get, whatever you do, don't let a tech put them in. There's nothig like, in fact its easier than changing a lightbulb.
Agile AL3000
Douglas WRL90
J&D Strat
Squier Tele
Sammick TR2
Douglas Draco
Peavey JSX
Bugera V5
Yeah, you'd think so but these buggers are pretty low down and I can't get a grip to pull them out. Would you get three new ones or just figure out which one is the problem and replace that? At $10-15 I'd be tempted to replace them all...