Vox AD30VT fault

[PGibson]

I wondered if anyone with technical experience could advise on this: my Vox AD30VT has developed a problem in the effects module. The choice of effect no longer matches what the rotary switch is pointing at (you get a seemingly random choice of effect), and bypassing the effects module only works for a short while: it will bypass the effects for maybe 20 seconds and then automatically switch the effects back on. It seems to have a mind of its own. I could happily live without the effects if they could be disconnected in some simple way. As it is, the amp is useless. (I have done a factory reset.)

Any thoughts?
Paul

[PGibson]

I presume from the lack of comments that no one has come across this problem before?
Paul

[Strummer]

Hi there,

I own two VOX AD30 VT's. One of them developed a bit of a "hit and miss" on the sound for a while, so, I 'thumped' it and so far it has behaved, but, i have never come across your problem before. They are, in general, very good little amps. VOX, like Fender, cannot afford to make bad amps as it would tarnish their good names, so, my advice would be to write direct to VOX's technical department and ask the question, perhaps they will take it in-house and sort it for you? I think it's worth a try.

[neil2726]

From experience Vox after sales service leaves alot to be desired!

[matthew blank]

I have the exact same fault with my AD30VT. If I play with the effects off, not bypassed, and the effects dial on delay with all the parameters off it plays fine for a while and all of a sudden it randomly jumps to some effect. If i have it in bypass it occasionally switches itself off bypass.

Have you by any chance sorted out the problem?

I am in South Africa and Vox support is poor.

[PGibson]

Hi Matthew,

I apologise for the slow reply. I posted my question on both the valvetronic.net and voxamps.com forum websites, and I followed the advice given which was essentially to use switch cleaner on all the switches and contacts. Sadly it did not cure the problem. However, I have since noticed that the rotary effects selector switch does not feel right: in some positions it feels 'slack' while in others there is the customary positive click as you select a position. I would say that the switch is mecahnically faulty. What I do not know is whether it is viable to replace the switch. To my inexperienced eye it looks difficult to get at the switch.

Paul

[brians356]

Paul,

I have exactly the same issue on my AD30VT.

Did you ever fix your broken effects selector switch?

Brian

[PGibson]

Hi Brian,
Sadly, no, I never did solve the problem. I ended up taking the amp chassis out of the cabinet, blanking off the hole, and converting the cabinet into a foldback monitor.
Paul

[brians356]

Thanks.

May I impose a bit more, and ask what steps you tried before giving up? (I have done the factory reset and pot cleaner, knowing they wouldn't work, but I haven't yet opened the case.)

My selector pot is physically damaged, it won't even turn now, but was never subjected to any mechanical trauma. I'm trying to understand what mode of failure could bind the pot. If the pot itself disintegrated, it seems one ought to be able to replace it.

Brian