Hi All,

I've had my AD50VT-XL for about 6 months now (bought it used). I absolutely love it but recently, when I plugged in, I got a lot of what sounded like static accompanied by massive amounts of squealing/whistling. Initially, I thought it was the guitar chord so I swapped that out but to no avail. I need to check to be sure but I want to say that the more I turn up the volume, the worse it gets. Has anybody else experienced this problem? Any help is greatly appreciated!

A little update. The problem still persists and I can say with 100% certainty that it's not the tube (I replaced it with another 12AX7, no change), it's not the guitar (it happens with all of my guitars) and it's not the chord (unless all 3 of mine are bad). I've also cleaned the jack sockets and reset the amp to no avail.

Here's what I have noticed, the problems are really bad on the high gain settings (especially Damaged) and when I turn on the effects (usually Chorus/Delay) it's almost unbearable. This is what's interesting, if I put my palm down across the bridge like (like I'm muting the strings), I get a quick, high pitched whistle and some buzzing. If I pull my hand off, it goes away. When I put my hand back down, I get a quick whistle and buzzing again. Any ideas? Thanks again!

nvm i see that uve tried with different guitars so its unlikely its your pups,
Id say take the amp in to a tech.

It sounds like there's a mains earthing problem. Have you tried the amp in a different location (ie both in & outside your home) & do you still get exactly the same problem?

It sounds to me like if the volume was set too high, with close pups ...

First, I don't know what you did to change channel on the video, but it may correspond to a user programm saved with too high values, not reflected by the actual knobs positions.

Did you check the volume of the high gain channel?
(On clean channel, no problem as it seems)

Having a try with a bigger distance between amp and guitar would be a good idea too.

I would check every knob; gain, volume, master, treble, and see if they do act or not.

Then set them all to 0, to see if the problem is sill there.

If not, just operate one by one; i.e.:

Set one to ten, the others to 0, then see if there is still the problem.

Then set it to 0 and try with another one set to ten, etc

After that, just set the master on 2/3, and repeating the 0-10 test for all other knobs, etc.

Then repeating the test with both master and volume on 2/3, etc.

Then with master, voulme, gain on 2/3, etc ...)

Maybe you could try too with only one effect at a time: only amp sim at first, trying different amps ...

Did you try this channel before, without having the problem?

I would say, standard answer, show it to a qualified technician (some failing solder or component, or so), maybe could he tell you directly where it does come from, and if you can do the repair by yourself ...

(There is still the possibility of another bad tube, even if brand new one ...).

I've tried 3 different cables.

I'd also suggest trying a different make of tube again - something like a Tungsol 12AX7 gold is a very quiet tube & might make a difference.

I'm curious to hear what the problem is. I've had this same amp for a year and a half now and have had zero problems. I bought it brand new. It never leaves my house, except when we moved last year. It's always played at bedroom or slightly louder levels. I haven't even had to do the jack cleaning yet. Sounds better than the day I got it.