At low output levels, my vox amp (sorry, I don't know the model; this was a long time ago before I knew anything about guitars and such) is making noises like static on a television or radio. When my guitar volume knob is low, the amp is completely silent. At about 75%, it has a hard time producing sounds. It has a slight sound, but mostly static. At 100% volume, it's just as it was when I bought it.

I know it's the amp because I've tried different guitars on it. Can anyone tell me if it's fixable or if I just need a new amp...Thanks!
I have this happen to me, except for the whole cranking it up and fixing it thing, when I crank mine it gets worse.

I've been told the problem could just be a wire sitting in the wrong place, but I reckon it could also be a transformer or capacitor. How long have you had it for?
My Gear
Cort VX-2V
Stagg BC300
Marshall JCM900 4100 DR
Marshall 1965A
Hartke HA3500 Combo
Have you done a visual inspection of your power and pre-amp tubes? A bad tube will glow a different color than others, "arc" (get spikes of light/sparks), or glow dimmer or brighter than others. Sometimes they also get microphonic, which you can test by lightly tapping them with a pencil or your finger after they get warmed up to see if they make noise. If you don't find anything there, it could be a matter of a dirty volume potentiometer -- if the contacts are corroded, they won't make good contact and can be staticy. And as mentioned above, could be an internal power component. But the tube thing is the easiest to test and is quite common, so that should be checked out first.
Hi, I'm Peter
If it's an older amp (15 years or more, it could be anything; get it fully checked over by a decent amp tech.

If it's a fairly modern amp, it's probably a microphonic preamp tube.
change power outlet, my amp always does this when my microwave is going =P

if not check the tubes, do the pencil test (hit each tube with a pencil to see if they are microphonic [see if you can hear the tappin])
I own a Gibson SG Standard
And I am officialy recognized as an SG commando

Gibson 2009 SG Standard --> Peavey Classic 50 2x12

RIP Lester William Polsfuss aka Les Paul 1915-2009
RIP Stephen Ray Vaughan aka SRV 1954-1990