B-52 amp head Buzz?static

[bouttree]

Hi, My B-52 amp head has a buzz or static noise….cord is ok,different guitars all do the same buzz. I need to fix this issue because the band plays at a loud volume. When I'm not playing the buzz noise is very annoying. Input jack is tight,I tried grounding the input jack to a external ground (the ground from the circuit panel "green wire"). I have no problem opening up the chassis and exploring the issue. I'm a retired Fighter Jet electrician and have knowledge of electronics. Actually not sure why I haven't fried my self yet?
Thank You,
Dennis
Msgt USAF retired

[eschertron]

Hi, My B-52 amp head has a buzz or static noise….cord is ok,different guitars all do the same buzz. I need to fix this issue because the band plays at a loud volume. When I'm not playing the buzz noise is very annoying. Input jack is tight,I tried grounding the input jack to a external ground (the ground from the circuit panel "green wire"). I have no problem opening up the chassis and exploring the issue. I'm a retired Fighter Jet electrician and have knowledge of electronics. Actually not sure why I haven't fried my self yet?
Thank You,
Dennis
Msgt USAF retired

Swapped cord for known good cord - check
Swapped guitar for known good guitar - check

Loose input jack is the next thing I would have checked, too. Verify that the contacts in the jack are tight against the plug when inserted?
Does the noise go away when nothing is plugged into the amp? If the noise is only present with something plugged in, it indicates the jack or the cord.

Is the noise present, does it change somewhat, or does it go away as the volume control is turned to zero? do the tone controls have any effect? These can indicate where in the circuit the noise is generated (or isolated).

Are you getting random noise bursts (static) or do you get a continuous buzzing sound?

Answers to questions like these can help the guys who really know what they're doing (not me!) locate the problem. From the info you've provided, I'd suspect a bad rectifier (is it a tube? Get one and swap it out, easy test) or a bad power supply filter cap. The good news is that there are folks here that can and will help.

[olddawg]

Have you tryed the amp in a different location? You could be picking up noise from lighting, etc. Triac light dimmers especially. I play a club occasionally that is next for to a gas station. Anyone playing a guitar with single coil pickups gets a hell of a buzz.

[Chuck H]

Noisy preamp tube?