AD30VT Need Help Diagnosing

[cisned]

K, I haven't had the time to look at all the post so I decided to post my own with all the symptoms that my amps currently has. The problems dates back since I first bought it, but has gotten worse and worse as years passed (I bought in 07). The problem is that it makes a static noise in the beginning and then the volume quickly fades and comes back, after a while the amp will lose about 95 percent of the volume, where you will need to turn it all the way up in order to hear a whimper of a sound.

Afterwards the volume is completely dead, but the amp will still have power going in as the lights are still on. The only way for it to be fixed is to turn the power on and off, while having the main volume and the power valve all the way down and gradually raise it. This works somewhat well, but as the more I play it, the problem will happen more frequently in shorter times, and even restarting it would work less and less.

I have opened the amp and cleaned up a bit, and saw the tube glowing even after the amp's volume goes completely dead. Everything seemed fine, but the only thing I noticed is that the volume will go dead just by shaking the amp (the part with the knobs, power source, and electric circuits). I also notice that waiting a bit will help the amp work better, and like I said before continuing playing it and constantly turning it on and off when the volume dies will make it worse.

[cosmicrepairdude]

Read this:
maintenance-tips-on-valvetronix-amps-t141.html

[cisned]

Yea its not that simple, this problem occurred when I just bought the amp and it was all clean. I did all of those steps already, because the guy from guitar center told me, and nothing changed. I'm pretty sure is a false contact, or a part that is malfunctioning in the electric board. Thanks for the help though.

[cosmicrepairdude]

Did you buy it new? It would have been under warranty for the first year - did you take it in then?

Since you mentioned the contacts and that shaking the amp makes a difference, you should try the procedure I've done to fix a completely different problem. You have nothing to lose by trying. It involves spraying contact cleaner/lube into various places. I'd also include spraying all the switches and pots.
See my first 2 posts on this page and then further down there's a little more on tube pins and speaker connectors: http://www.voxamps.com/forum/topic.php?id=3716&page=19

The glow you see is not the tube, that's an LED to simulate tube glow, since the tube doesn't get hot enough to glow (cheesy, huh?). If you can borrow another 12AX7 tube, you could swap that in to see what happens.

Does the same problem occur when using the headphone/line out jack? Plug in some phones and/or plug it into another power amp or PA to find out, if you haven't done that yet.

I should also point out that the headphone jack's built-in switch can get so gummed up that it can take several cleanings in a row to get it clean, and also that the problem can crop up early in the amp's "life". Retrobob has designed a tool to help in this regard.
Look at this forum for that and more: technical-articles-f51.html