Tube amp buzz

Try it. Probably won't fix it.

The springs are there to keep your tubes from coming loose and falling out.

I was going to lay my hand on the spring to see if it would quiet it down, but I thought better of putting my finger in there when the amp is powered up.

:idea:
:shock:

I was going to lay my hand on the spring to see if it would quiet it down, but I thought better of putting my finger in there when the amp is powered up.

Tubes get hot and will burn your hand - that's a more likely risk than getting electrocuted from touching the tube (though it's not my fault if you do get electrocuted too). If you want to touch stuff in there then get a chopstick - it's wood and so won't conduct (unless you pick one of the traditional Korean kind which are made of metal so choose one of the disposable kind). If you don't have any handy then a short piece of dowelling is good. A pencil may work but remember that the graphite in the centre of the pencil is a conductor.

Are you sure that it's a physical vibration? Perhaps it's just that when tthe amp is turned up louder it's amplifying a low buzz to where you can hear it. Perhaps it's 60Hz line noise or flourescent lights being pickup up by your guitar etc.?

It should be quite easy to tell the difference between a mechanical buzz that's excited by playing (like the one that's bugging me right now from somewhere in the vicinity of my resonator's cones) and an electrical hum, which should be pretty constant. Depending on where in the circuit it's being picked up, the volume or gain controls might or might not affect the level of hum.

FWIW, usually power line frequency noise is called "hum" and other frequencies are "buzz."

A piece of electrician's tape temporarily wrapped on the springs will damp any vibrations. Don't leave it on permanently, just long enough to check.

Speakers often get noisy, and parts around grilles and cabinets get loose. Just about any part of the amp can get loose and buzz.

It's most definitely a mechanical buzz. It's coming from behind the cabinet, not in front of the speaker. The electrical tape is a great idea. I'll try it this weekend and see if I can pin it down.

As for the springs, I have seen one of those spring retainers be too loose from saggy springs and not fit tightly on the tube. That might buzz. A lot of those retainers are riveted to the socket and are difficult to replace without replacing the socket. Some are attached with screws that also hold the socket into the chassis; they're easy. I just peeked in the back of my Valve Junior, and its retainer springs are just hooked into holes in the chassis. No problem! Might be trickier than it looks getting them unhooked and rehooked, though.

The springs are hooked on. Probably the same as the EVJ (I sold mine, so I can't compare the two). I got them off with needle nosed pliers. The amp did not buzz with them off, so when I put them back on, I bent the four arms out away from the tube. This pulled the bracket up more firmly against the bottom of the tube, and also the arms are not resting against the tube itself.
Big difference!!! Now the only things that make noise when the amp is cranked are the dishes in the cabinets and the windows in the house!!!

Thanks for your help!! One other thing. I wanted to try removing the tubes while I was messing around. Just so I know how to do it if I need to replace them. I thought I could just pull on them, but they are in there pretty firmly. Especially the power tubes (I think those are the ones with the metal shielding around them) I was afraid to pull to hard. Should I not worry and just pull on them?

The power tubes are bare. They do just pull straight out, but may require a little wiggling to come loose easily. The preamp tubes have that metal shield to keep out electrostatic interference. The shield is locked into the chassis and releases by turning it a bit. Clockwise on my VJ, looking down at the top of the tube.

Note that the pins in the bottom of the tubes have a gap in the circle. That has to line up with the corresponding gap in the holes in the socket, then the tube pushes straight in. Changing tubes is no harder than changing a light bulb, really, once you get used to it.

The power tubes are bare. They do just pull straight out, but may require a little wiggling to come loose easily. The preamp tubes have that metal shield to keep out electrostatic interference. The shield is locked into the chassis and releases by turning it a bit. Clockwise on my VJ, looking down at the top of the tube.

Note that the pins in the bottom of the tubes have a gap in the circle. That has to line up with the corresponding gap in the holes in the socket, then the tube pushes straight in. Changing tubes is no harder than changing a light bulb, really, once you get used to it.

Thanks!

You're welcome. :D

Check the speaker too. I used to have a Marshall combo, every few months the screws holding the speaker would work loose from vibrating and cause a racket. In fact, I had to go over the entire cabinet every month or so because all the screws would work loose. That's a Marshall for ya. :D

I did check the speaker when I first opened the back. Everything is tight. It was definitely the springs. I can crank that mutha now without any buzz.