I have a Laney AOR Pro-Tube Lead 100 watt tube amp which is a one channel amp with 2 separate inputs, one low sensitivity and one high. A few days ago I started having problems with it because it wouldn't give me any distortion at any volume even with the preamp+master volume cranked all the way up. In addition to this when the preamp+master volume were cranked it didn't get nearly as loud as it would get if it were running normally. I thought I needed new preamp tubes as the amp is fairly old and I bought it used so I don't know the last time the tubes got changed.

Today I turned the amp back on to see what was going on and I had distortion in the high sensitivity input with the preamp cranked but none in the low sensitivity. This confused me because last time I checked both inputs weren't giving me any distortion and I hadn't touched the amp for two days before I tried it today. When I checked the back and took the caps off of my preamp tubes I saw that both of the tubes to the right weren't glowing at all.

Aside from the fact that those two tubes didn't light up what else could be wrong with and what could've caused it to not give me any distortion when I turned it on before today.
I'd have someone who knows what they're doing check your powertubes. Typically most problems with tube amps are fixed by retubing, but sometimes other things can be the issue. If you bring it to a tech, have them check EVERYTHING from filter caps, to the solder joints.

I've also hear the effects loop in and out can give problems. Try plugging a cable in and pulling it out a coupla times in both and see if that helps.

Have you checked your guitar and cables? I remember when I got my tube amp (coincidentally an AOR ) that I thought all sorts of shit was wrong with it. Turns out it was fine and I was just abusing the EQ, in bad ways. I was also playing with a low tuned shorter scale guitar, and realized that its just not the same as playing with my higher tuned, longer scale guitar.

AORs, (at least mine) seem to be rather finicky. Mine did a little volume cutting once, but it came back and never did it again. Remember too that the low sensitivity shouldn't have ALOT of distortion, but I think none is a little strange as well. Just play around with it a bit more, and if you do have more problems, bring it to a tech.
Last edited by Quinlan at Jun 24, 2010,
Thanks man I would've taken it to a tech sooner but my local store sucks (they consider a guitar setup changing strings u__u ) so I have to go all the way downtown to get my stuff checked and I don't have a car lol.

I just ordered a new set of preamp tubes yesterday, is there still a chance that it could be the power tubes even tho they all light up how they're supposed to?
It is possible to have two faults. The power valves may be dying and you didn't notice but when a preamp valve died it made you sit up and take notice. From what you said I'd buy a set of output valves too.
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