VOX AD120 VTX Sound Dropping Please Help!

[jamman1701]

Hey guys I'm new to the forum.

I have a VOX AD120 VTX head. And the other day I noticed while I was playing that the sound suddenly dropped off for about 20 or 30 seconds then it came back up to full volume and then after a while the volume dropped off again. This keeps happening. I don't know much about amps as far as this stuff goes. This is my first valve amp.

Can anyone give me a diagnosis on the problem? If u could tell me how I can fix the problem I would appreciate it greatly.

Thanks guys

J.A.M

[izzybell2810]

Hey guys I'm new to the forum.

I have a VOX AD120 VTX head. And the other day I noticed while I was playing that the sound suddenly dropped off for about 20 or 30 seconds then it came back up to full volume and then after a while the volume dropped off again. This keeps happening. I don't know much about amps as far as this stuff goes. This is my first valve amp.

Can anyone give me a diagnosis on the problem? If u could tell me how I can fix the problem I would appreciate it greatly.

Thanks guys

J.A.M

Hi there, I'm pretty new here myself. You're in the right place to get the info to fix your amp. There are lots of very helpful, knowledgeable guys around here. I've not really had any dealings with any of the valvetronix range.
You say the vol is dropping out and then returning. When the amp is opperating normally i.e. when the sound comes back up to normal level, try giving the head a sharp whack with your fist to see if you can induce the vol drop. If you can there is a loose connection somewhere. Try plugging a patch lead from the effects send to effects return. If this cures the prob then the contact braekers on the jacks need cleaning. Plug your guitar into the effects return, Does it happen now? if not the prob is in the preamp. You need to isolate where the prob occurs and the above checks should do that.

Dave.