Question:
My classic 30 is making a subtle humming noise (not really loud but quite annoying to me) whenever I plug an effect or even a cable accross the effect loop. It sounds fine otherwise. Any idea what may have caused this?
Any suggestions for tubes, in case I need to have new ones?
Thanks.
Answer:
I may not know the problem, but I think it is safe to say that the tubes aren't the problem. My guess is that something in the loop isn't shielded the way it is supposed to be. Also, it could be the cables you are using. Try plugging in some different ones to see if it has an effect on the noise. That will at least give you a general idea of where the problem is.
Answer:
Originally Posted by PianoMan I may not know the problem, but I think it is safe to say that the tubes aren't the problem. My guess is that something in the loop isn't shielded the way it is supposed to be. Also, it could be the cables you are using. Try plugging in some different ones to see if it has an effect on the noise. That will at least give you a general idea of where the problem is.
I did try switching cables but the hum was still there so it's not the cable. As far as the shielding goes, is there anyway I can test it? Thanks.
Answer:
Well, again, i'm not that knowledgable about amps or their workings. I'm pretty much guessing here. For shielding, from what I can tell it is more a matter of if it is there, rather then if it is working. But as I said, I don't know amps, and i'm not even sure if effect loops utilize shielding.
Answer:
A couple thoughts -
Since you say it does that with just a single cable connecting out to in, it sounds like a ground loop issue that could be caused by:
It could be jacks' mounting nuts (unless they are plastic) not being tight against the metal of the chassis. If the FX loop 1/4" jack nuts are metal, tighten them. If they are plastic nuts, it isn't grounded to the chassis that way, so don't worry about it.
If that doesn't do it, it could also be a broken solder connection of one of the jacks' solder lugs on the PCB they are mounted to, or simply the connectors are dirty. Try gently wiggling or twisting each end of a cable connecting the out to the in. If you can make it better/worse/change it could be a broken joint, or possibly just the jacks need cleaning.
Answer:
Originally Posted by Major Tom A couple thoughts -
Since you say it does that with just a single cable connecting out to in, it sounds like a ground loop issue that could be caused by:
It could be jacks' mounting nuts (unless they are plastic) not being tight against the metal of the chassis. If the FX loop 1/4" jack nuts are metal, tighten them. If they are plastic nuts, it isn't grounded to the chassis that way, so don't worry about it.
If that doesn't do it, it could also be a broken solder connection of one of the jacks' solder lugs on the PCB they are mounted to, or simply the connectors are dirty. Try gently wiggling or twisting each end of a cable connecting the out to the in. If you can make it better/worse/change it could be a broken joint, or possibly just the jacks need cleaning.
I tried the suggestions to tighten the nuts and wiggling/twisting the cable ends but sadly, it's still humming Thanks though
I guess it's either taking the amp to a shop or just live with it... most likely I'll end up with the later since it's not such a big deal