Static coming from amp when playing certain notes...

[jmentch]

Hello everyone. I've been having an issue with my amplifier lately, and I'm looking for some possible ideas as to what the problem/solution could be. My amp is an old (now discontinued) 2 channel Peavey Triple X. It's all tube, and I know there were two versions of the amp, one with on-board effects and one without (just an effects send/return on the back); mine is the version without the on-board effects. The problem is that whenever I play certain notes (usually always B and C, sometimes A and D) on the guitar when plugged in and turned up, I can hear an obvious, present crackling/static sound. Sometimes it lasts long with the note and other times it might be quick, but it's always there with those notes. I thought maybe it could be the preamp tubes, though I don't know whether or not they've ever actually been replaced (the amp was given to me used as a gift, I've had the amp for around 7 years). I changed the power tubes around maybe 5 to 6 years ago, and they seem to be glowing and working as normal. When I was looking at the tubes, I noticed that one of the preamp tubes was seemingly glowing less than the others, and it being the same brand (Sovtek) and type of tube as the other preamp tubes, I took it as that one tube was going bad, and I bought a brand new one (of different brand, JJ Electronic) to swap out the old one. I did this, hoping it would make some kind of improvement, but nothing changed. So now, I'm thinking of changing out all of the preamp tubes, but I'm wondering now if that doesn't solve the problem, even if it is the problem, what else could be the issue? A short somewhere, wiring gone bad, tube sockets...? I've tried different cables as well and there's no difference. I've even changed power cords and plugged into different wall sockets, all with no change. It seems like there could be any number of ideas, but I'm hoping that maybe anyone could have a more narrowed idea or solution as to what to do.

Also, I don't know if this makes any sense or helps at all, but I've found that when sitting on the amp, the crackling/static noise is less present, but it's still there to a degree. Also, when I knock on the top of the amp with my hand, without a guitar plugged and with the volume on the amp turned down all the way, I can hear a similar static sound.

Thanks in advance to anyone who can help.

 

[beaubrummels]

Re: Static coming from amp when playing certain notes...

Welcome to the forum.

The description makes me think it's your V1 tube being microphonic, or otherwise a dirty, loose component like a pot. I have a Vox that behaves like that and it's the V1 tube being microphonic. My Marshall makes the static sound, but not related to sound/notes or tapping on the amp, and it's the volume/tone pots in that case.

 

[zzmoore]

Re: Static coming from amp when playing certain notes...

You are starting at the right place.
Try the tubes...but also try cleaning the sockets...something is better than nothing...even alcohol on a Q-tip,into thw sockets can do it...or dip the tube pins into the alc...you need to get some on there somehow...enough so itr does the job and does not evaporate in 1 second. You can poor some alc in a little cup, then dip the tube pins, then get them right into and out of the sockets several times.
Try the same routine with all the jacks and plugs.
This would not be the first PV that needed to have socket connections re-flowed...but try the easy stuff first.
It COULD be a lot of things...like beau mentions above, it could be a pot that has loosened up a bit, or a jack, or a cold solder joint, etc etc. Try the tube and cleaning first.
6-7 years is a Long Time for tubes.
good luck
assume you tried new/different guitar..speaker cab... cable(s)... etc etc

 

[Scott_F]

Re: Static coming from amp when playing certain notes...

Certain notes mean a mechanical issue. Swap some preanp tubes like others have recommends. But my experience building amps is you have a bad solder joint somewhere. Been there done that. Check your speaker input(s ) grounds.


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[ken361]

Re: Static coming from amp when playing certain notes...

Buy some Deoxit D5 spray at Radio Shack and spray each of the tube pins. Do one tube at a time and work the tube in and out of the socket a few times, then the power tubes. I have a new amp but used tubes were causing static for me too! never had that problem b4 but the spray worked! playes smoother now because of better contact. Every amp owner should have a can! cleans your electronics also.