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View Full Version : AD30VT cutting out/volume drop



MPsound
February 17th, 2007, 05:47 PM
Well, with my new purchase of a Bad Monkey, I really must have given the AD30VT a workout today. At one point the volume dropped significantly on it's own, and not only that but the sound was very "thin" and "fuzzy". I was running the amp louder than usual for sure.

Anyone else here experience this with an ADxxVT?

Power cycled the amph a couple of times with no change, moved the Master - not sure if I had tried moving the Volume or Gain knobs though - I don't think so. I think I had moved the power attenuator on the back as well. Finally after another power cycle the amp came back to normal. So I began to wonder if I had tripped an over current protection circuit or an over temp or something. Does anyone know if these amphs have any such circuitry in them?

Browsed through some posts here and on Valvetronix and Patchtronix and found a LOT of very similar reports. Read an interesting theory - I was using presets and if the Volume or Gain knob moved some due to say vibration, and was set low to begin with, that could cause sudden volume loss. I like that idea as it would mean less of an issue with the amp. :) But it seems the pot needs to be turned a decent amount - I think more than what would occur with vibration. Although - maybe internally it can change enough, I don't know, just guessing at this point. Could also be vibration on the input jack/plug connection... The amph and cables are not that old to be contaminated already. And besides the volume drop, the sound was "thin" and more distorted/fuzzy.

I need to pay closer attention next time as to what brings the amp back. I do not think I touched the Gain or Volume (or cables) this time, only Power, Master, and on/off switch.

I can say this - I'm so pleased with Bad Monkey that if it comes down to him or the AD30VT - I hope the Monkey wins the fight! The Monkey inspired me to pretty much max out the Master and Power Attenuator... :D

MPsound
March 3rd, 2007, 08:52 PM
In case anyone is interested, I thought I'd post an update... I've been giving the AD30VT a workout at times since, and I think I narrowed the issue down to the input jack connection. The cables I'm using have a gold coating on the plug and although I have not removed/re-inserted the plug in the amp all that often, there is some wear on the coating of the jack. Those same cables on the pedal and guitar ends have no wear at all.

Oh, and it is a straight plug so I think there was maybe an intermittent connection issue - maybe worse at loud volumes due to vibration. Posts on Valvetronix and Patchtronix indicated others having such connection issues. I first "braced the straight plug better so there was no side pulling tension, and finally switched to a right-angle plug, and have not had an issue since.

tot_Ou_tard
March 3rd, 2007, 10:04 PM
MP did you try resetting the computer? Check the manual. I've also heard that using contact cleaner on the jacks helps a lot.

MPsound
March 3rd, 2007, 10:13 PM
Yes, thanks. I have done that in the past... press channel + write while powering on, I think once the channel LEDs blink, release buttons, then press write. Don't interrupt until all light's flash. I read that as well about the contact cleaner. I'm just glad my amph seems ok.

tot_Ou_tard
March 3rd, 2007, 10:16 PM
I'm just glad my amph seems ok.
Me too! Rock on, MP! :DR :R :DR