#1
Hi all. I recently got my hands on a used Peavey Valveking 112. When I got it, it worked great. I was out of the country for about a month, though, and when I got home I discovered that the amp had started crackling. There are no 'pops' that one would expect from blown tubes, and it only starts crackling after it's been on for five minutes. I've never heard anything like it. It sounds a little like the background crackling you get with a really old radio, and it's only audible when everything is turned on, but I'm not playing. The actual amp tone sounds normal to me. I've tried different guitars and cables, and it's always the same. Anyone have an explanation?
#2
I am guessing it is a preamp tube problem.

Could be lots of things though.

Flip the amp upside down and take the aluminum cylinder shields off of all three preamp tubes.

Turn the amp on and play as normal.

Does one tube get real bright?

Either way, swap the preamp tubes around.

Spray some dioxit contact cleaner on all the tube pins and make sure all tubes are in snug.

Buy some new preamp tubes.

I have a vid that might help you when I get home.
Last edited by 311ZOSOVHJH at Feb 16, 2014,
#3
Quote by 311ZOSOVHJH
I guessing it is a preamp tube problem.

Could be lots of things though.

Flip the amp upside down and take the aluminum cylinder shields off of all three preamp tubes.

Turn the amp on and play as normal.

Does one tube get real bright?

Either way, swap the preamp tubes around.

Spray some dioxit contact cleaner on all the tube pins and make all tubes are in snug.

Buy some new preamp tubes.

I have a vid that might help you when I get home.



Thanks for the help man. I actually took the shields off and it stopped. Though one of them seems to be really microphonic. That may be it.
#6
When I had 'crackeling' on my Valveking it was because a preamp tube was not seated all the way down and it was causing a tube pin to arc with the socket - but obviously I've had microphonic preamp tubes too. If you don't have new/different preamp tubes to try the only thing you can do is swap them around and monitor their performance. This is also why I leave those tube cover off of all of my amps. I can't see shit.

Good luck,
#7
start with the easy solution as it is most likely correct. mine had to be sent in for repair as a resistor went bad (don't know which one off the top of my head) this caused cracking which got worse with time until the amp didn't work properly. took it to a local peavey tech and they couldn't figure it out. called peavey and they seemed to know right off the bat. had to send it in and guessing it may have been a common issue that they'd prefer not to advertise as I would have thought that a certified peavey tech would know.
#8
Quote by monwobobbo
start with the easy solution as it is most likely correct. mine had to be sent in for repair as a resistor went bad (don't know which one off the top of my head) this caused cracking which got worse with time until the amp didn't work properly. took it to a local peavey tech and they couldn't figure it out. called peavey and they seemed to know right off the bat. had to send it in and guessing it may have been a common issue that they'd prefer not to advertise as I would have thought that a certified peavey tech would know.


I wish there was someone I could take it to. Sadly we don't have anywhere good to take broken amps in Ireland.