Problem with my Express. Help

[Mont]

Last nite at rehearsal my amp would start breaking up as i turned my volume knob down to get a clean sound and then the signal would cut out about half way. changed tubes same thing. anyone got any idea?

[selloutrr]

Cold solder point?
Shorting pot?

[passfan]

Any news Mont ? Tell me your back to juicing your grunties Mont.

[Mont]

I can't figure it out. when I bring down the guitar volume(any guitar) the amp starts to break up and then shuts off about halfway. changing tubes has no effect. plus after checking out other TW's I noticed mine does'nt have as much gain. power out the ass, but not the gain as the ones i listened to.

[passfan]

I can't figure it out. when I bring down the guitar volume(any guitar) the amp starts to break up and then shuts off about halfway. changing tubes has no effect. plus after checking out other TW's I noticed mine does'nt have as much gain. power out the ass, but not the gain as the ones i listened to.

Have you tried a different guitar with it? Well nevermind...
Reading comprehension is not my strong suit.

[rooster]

When you said 'not as much gain as other TWs' it made me focus on your V2 hookup. I would look at the 150K resistor and make sure you have it connected correctly.

And without pics its a guess.

[passfan]

Do you think a bias resistor could be a wrong value? Might have an effect on gain. Perhaps a bad bypass cap?

[Mont]

yeah still trying to get a camera. and the 150k is hooked up according to the expess build guide.

[Mont]

I am gonna pull the bypass caps and check them.is there an acceptable tolerance for the bypass caps? guess i should have checked all the patrs first. you live you learn.

[passfan]

I am gonna pull the bypass caps and check them.is there an acceptable tolerance for the bypass caps? guess i should have checked all the patrs first. you live you learn.

I would double check the values of my bias resistors and see that the caps are installed with the correct polarity. If they look good they probably are. Bypass caps affect gain. I would check the values of everything around v1 for sure. I don't know how you're set for spare parts. I always over order when I buy something so it's no big deal just to change something out. Of course, my Express is taking a dump right now as well so take it with a grain of salt.

[Mont]

I replaced the bypass caps still no change. anyone else got an idea?

[rooster]

pics will be your salvation. don't be shy, we've seen it all.