#1
I thought this topic would be best in here as it's more of a technical question.

My amp buzzes when I play the bass notes on my guitar. The buzzing is like a vibration as though something is loose.

When I sit on the amp the buzzing stops, so I'm thinking it's definitely something vibrating against something else.

Has anyone experienced this before and know how to fix it?

Thanks.
#2
Tighten all the screws you can find, including the ones holding the speaker (don't tighten those too tight though, you could warp the frame if you force it).
#3
if you turn the bass down on your amp, does it lessen? it might be something as simple as maybe the screws in your amp are loose and theres something vibrating. Have you opened up your amps casing and looked
-------------------------------
Faded Gibson SG Special - Black ice mod
Seymour Duncan SH-5 in bridge
B-52 AT 112
Ted Weber Mass100 attenuator
EHX Small Clone
EHX Metal Muff
DIY Modded tubescreamer
Dunlop 535Q Wah
Wax Potting tutorial
#4
check the joints of the cab and make sure one isn't loose before you start tearing it apart
Out here you've gotta know where your towel is!
#5
my firend had a similar problem with a small crate practice amp
in his case the handle for picking up the amp had come loose
causing it to rattle resulting in the buzzing sound with high bass
when we sat down on it it went away

it could also be the screen itself covering the speaker that has come loose
it could be a number of things

the fact that you said it went away went you sat on it tipped me off
check all your screws and fastenings to make sure they are tight
and troubleshoot the problem
#6
Fixed! I noticed that one of the screws on the top would never tighten...it just kept going round and round the more I screwed. I opened it up and there is supposed to be a kind of "washer" type thing that tightens it...turns out it was just loose, rolling around inside my amp!

Quite strange seeing as I've never taken it apart before!

Thanks for everyone's help.
#7
Ok. After fixing the buzzing on this amp, I have noticed another problem.

If I plug headphones into the headphone socket the sound comes out of the headphones fine. However, when I unplug them, it takes a while for the sound to come back out of the amp's speaker. The sound will come back slightly, but then crackle and then suddenly stop again.

The way I get the sound back is by fiddling with the gain and volume knobs and turning it off and back on a few times.

Oh, and just for the record, it's a Marshall MG series amp.
#8
^that could be down to any number of problems. Bad headphone jack or broken solder joint are the most likely issues.
Not taking any online orders.
#9
Good luck with the MG

Sounds like a solder joint..I had something similar happen on my Hartke A25
Nope, no sig here.
#11
Well, I took the amp apart today and had a look at all the internal components and I couldn't see anything that looked irregular.

After I put it back together it was fine! Still crackles a bit when I take the headphones out but it's perfect after a second, unlike before where I had to keep tweaking the knobs and turning it off to get it work.

Magic fingers...it's the only explanation.
#12
Quote by grantjames
If I plug headphones into the headphone socket the sound comes out of the headphones fine. However, when I unplug them, it takes a while for the sound to come back out of the amp's speaker. The sound will come back slightly, but then crackle and then suddenly stop again.
The headphone jack has a "switch" incorporated in it. When you plug the headphones in, it bends the contacts away from another set of contacts. That other set of contacts connects the circuit to the speaker.

When you remove the headphone plug, the contacts are supposed to relax back into position, reconnecting the circuit to the speaker. Cheap jacks fail, because they quickly lose their shape and they don't make good contact when the plug is removed. At first they will make contact, but just barely. Eventually they won't even touch.

Poorly soldered joints on a printed board can act in a similar fashion. When you insert and remove the plug, you bend the entire jack assembly slightly. It's possible to improve or degrade the contact between the lugs of the jack and the printed board.

Quote by grantjames
The way I get the sound back is by fiddling with the gain and volume knobs and turning it off and back on a few times.
Turning it on and off probably does more than fiddling with the knobs. The current surge through the headphone jack heats the contacts. This will cause improved connection. ... temporarily.

Quote by grantjames
Oh, and just for the record, it's a Marshall MG series amp.
"Records are made to be broken." lol

Quote by grantjames
Well, I took the amp apart today and had a look at all the internal components and I couldn't see anything that looked irregular.

After I put it back together it was fine! Still crackles a bit when I take the headphones out but it's perfect after a second, unlike before where I had to keep tweaking the knobs and turning it off to get it work.

Magic fingers...it's the only explanation.
Whatever the reason, it's working now. But for how long? This problem will return. Count on it.
Meadows
Quote by Jackal58
I release my inner liberal every morning when I take a shit.
Quote by SK8RDUDE411
I wont be like those jerks who dedicate their beliefs to logic and reaosn.