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amp buzz removal
Old 1 week ago
  #1
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Thread Starter
amp buzz removal

I have this problem in the room I just moved into, my amps buzz so loudly the noise is as loud as the guitar signal. If I shut off everything and play in the dark with only the amp plugged into a wall socket, it's mostly fine, a little bit of buzz in a manageable amount. As soon as I flick on a lamp or plug in a power strip, the buzz is fed and gets louder. I'm wondering if a power conditioner will help me at all, or if there's some other solution so I can have the lights on AND record as clean as possible a signal from my amps.
Old 1 week ago
  #2
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Ground loop! Need to find the problem. I`d start with one of these. I think I paid maybe $10 for it.

One of the connections to your outlets and/or wire splice to light light is bad/loose.

-ALSO the new LED bulbs can cause bad noise! Their operating frequency is in the hundreds, not the 60hz we had. I recommend halogen bulbs ONLY.
Old 1 week ago
  #3
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First, be sure it's the amp...not interference being picked up by the guitar...what happens when you unplug the guitar (but leave the lead plugged into the amp)?

Second, there are many potential sources of interference, but an easy one to check with knowing that lights are a problem...CFL bulbs can be pretty bad and especially flickering bulbs at the end of their life can also do odd things. You can always aim your guitar closer to the lights and listen for offenders.
Old 1 week ago
  #4
NOT a ground loop. A ground loop would only happen if there was another device connected to the amp with an additional path to ground (forming a loop - get it?)

Are any of those lights on dimmers? Are any of them fluorescents (including CFL bulbs) or LEDs? Are there any devices containing motors? Are there any devices that use switching type power supplies (including computers?) Video devices?

Does the amp still do it if the guitar is not plugged in? Does moving the guitar around change the volume of the noise?

Something in (or near) your room is generating RFI (Radio Frequency Interference) which is being picked up by your guitar and/or amp and amplified.
Old 1 week ago
  #5
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Most likely a light dimmer or something else running close by or on the light switch that generates noise like Fluorescent lights which have a high voltage transformer (ballast)

Sounds like you need to shield you guitar better. Get some copper foil from Stu Mac and shield the cavity (and pick guard if its a strat) Be sure to add a ground wire to the foil. Shielding | stewmac.com You can use the metallic paint too, just be sure you paint over a ground tab otherwise the shielding does nothing.
Old 1 week ago
  #6
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kafka's Avatar
Quote:
Originally Posted by John Eppstein View Post
NOT a ground loop. A ground loop would only happen if there was another device connected to the amp with an additional path to ground (forming a loop - get it?)
Yeah, not strictly a ground loop, and probably not through the amp's socket, but I'd say his description indicates a ground problem somewhere else in the room. Return current going through his ground instead of the neutral would give him some uncancelled EMI.

I used to have major problems when the neutral was out to all of my neighbors houses, and all their return current was going through my water main. Fortunately, the power company was willing to solve that. But, since OP can turn it on an off himself, I'd say there's a problem with the local circuit in that room. Barcelona's device should work if it's a socket, but it could be a light switch.
Old 1 week ago
  #7
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Quote:
Originally Posted by John Eppstein View Post
NOT a ground loop. A ground loop would only happen if there was another device connected to the amp with an additional path to ground (forming a loop - get it?)

Are any of those lights on dimmers? Are any of them fluorescents (including CFL bulbs) or LEDs? Are there any devices containing motors? Are there any devices that use switching type power supplies (including computers?) Video devices?

Does the amp still do it if the guitar is not plugged in? Does moving the guitar around change the volume of the noise?

Something in (or near) your room is generating RFI (Radio Frequency Interference) which is being picked up by your guitar and/or amp and amplified.
I just call anything involving a wiring fault on a given circuit of outlets a ground loop since there are different types. https://en.wikipedia.org/wiki/Ground_loop_(electricity) I know what you`re saying though.
Old 1 week ago
  #8
Quote:
Originally Posted by BarcelonaMusic View Post
I just call anything involving a wiring fault on a given circuit of outlets a ground loop since there are different types. https://en.wikipedia.org/wiki/Ground_loop_(electricity) I know what you`re saying though.
No.

"Ground Loop" is a very specific term for a very specific problem. I refer you to the white papers written by Bill Wheelock on the subject that are available through Jensen Transformer or AES. I'd post them here if not for copyright issues.

Ground loops are a complicated enough subject by themselves without people confusing the issue with spurious non-information.

And RFI problems have NOTHING AT ALL to do with grounding.

It appears that the ignorant person who wrote that article has considerable confusion between the issues of ground loops and inductive leakage which are totally different problems.. I'll have to edit it when I finally get around to joining Wikipedia's editorial staff as they've asked me to do.
Old 1 week ago
  #9
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Quote:
Originally Posted by John Eppstein View Post
No.

"Ground Loop" is a very specific term for a very specific problem. I refer you to the white papers written by Bill Wheelock on the subject that are available through Jensen Transformer or AES. I'd post them here if not for copyright issues.

Ground loops are a complicated enough subject by themselves without people confusing the issue with spurious non-information.

And RFI problems have NOTHING AT ALL to do with grounding.

It appears that the ignorant person who wrote that article has considerable confusion between the issues of ground loops and inductive leakage which are totally different problems.. I'll have to edit it when I finally get around to joining Wikipedia's editorial staff as they've asked me to do.
Ok, I get it. But it could be a loose ground in the circuit or the "new" light bulbs like I said since it goes away when he turns off the lights. In any case, I would test the outlets with the tester I posted and check the light bulbs, if it goes away when the lights are off. It could be a bad splice to the lights, I don`t know.
Old 1 week ago
  #10
Quote:
Originally Posted by BarcelonaMusic View Post
Ok, I get it. But it could be a loose ground in the circuit or the "new" light bulbs like I said since it goes away when he turns off the lights. In any case, I would test the outlets with the tester I posted and check the light bulbs, if it goes away when the lights are off. It could be a bad splice to the lights, I don`t know.
Those testers are kinda OK (I have a couple), but really don't tell you a lot. They're mostly useful to tell if hot and neutral or neutral and ground are reversed or if ground or neutral are completely open. They won't tell you if corrosion has increased the resistance of one or more lines, for example, and that can definitely set up a ground loop condition if the resistance is different on the grounds running to different sockets but only if his rig has more than one device with a ground. However THAT DOESN'T HAVE ANYTHING TO DO WITH THIS SITUATION, since he doesn't have multiple ground paths to his amp, unless he isn't telling us something. IT'S NOT A GROUND LOOP, there's no "loop" there!

Since it goes away when he turns off the lights, I'm betting there's a dimmer somewhere (BTW, dimmers emit more noise when they're turned DOWN to around 1/2 to 1/3 output, and much less when they're all the way up) or one or more noisy fluorescent (including CFL) or LED lights. These days it's a fair bet that somebody replaced all the incandescent bulbs with CFLs.



A "bad splice" to the lights? I doubt it. That wouldn't make them generate RFI. A really, really bad connection that's sparking, maybe - and that's a fire hazard. But a connection that bad is very rare, and the noise would be an intermittent crackle, not a buzz or hum. And the increased resistance would probably be causing tripping breakers.
Old 6 days ago
  #11
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Thread Starter
I'm gonna try a Furman power conditioner, see if that helps. There's definitely radio station interference, I pick up station signals loud & clear sometimes.
Old 6 days ago
  #12
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Quote:
Originally Posted by lunaquesa View Post
I'm gonna try a Furman power conditioner, see if that helps. There's definitely radio station interference, I pick up station signals loud & clear sometimes.
Most consumer grade "power conditioners"are literally a rackmounted power strip --- it is VERY unlikely that the noise you are experiencing will be at all affected by adding one.
Old 6 days ago
  #13
Quote:
Originally Posted by lunaquesa View Post
I'm gonna try a Furman power conditioner, see if that helps. There's definitely radio station interference, I pick up station signals loud & clear sometimes.
A power conditioner won't help RFI, certainly not a Furman, which contains no effective noise protection. It's essentially nothing more than a rack mount surge protector.
Old 6 days ago
  #14
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Quote:
Originally Posted by John Eppstein View Post
Those testers are kinda OK (I have a couple), but really don't tell you a lot. They're mostly useful to tell if hot and neutral or neutral and ground are reversed or if ground or neutral are completely open. They won't tell you if corrosion has increased the resistance of one or more lines, for example, and that can definitely set up a ground loop condition if the resistance is different on the grounds running to different sockets but only if his rig has more than one device with a ground. However THAT DOESN'T HAVE ANYTHING TO DO WITH THIS SITUATION, since he doesn't have multiple ground paths to his amp, unless he isn't telling us something. IT'S NOT A GROUND LOOP, there's no "loop" there!

Since it goes away when he turns off the lights, I'm betting there's a dimmer somewhere (BTW, dimmers emit more noise when they're turned DOWN to around 1/2 to 1/3 output, and much less when they're all the way up) or one or more noisy fluorescent (including CFL) or LED lights. These days it's a fair bet that somebody replaced all the incandescent bulbs with CFLs.



A "bad splice" to the lights? I doubt it. That wouldn't make them generate RFI. A really, really bad connection that's sparking, maybe - and that's a fire hazard. But a connection that bad is very rare, and the noise would be an intermittent crackle, not a buzz or hum. And the increased resistance would probably be causing tripping breakers.
Anything that causes current to divert to the ground rather than the neutral will cause there to be uncanceled EMI in the room. Electromagnetism exists by sheer virtue of having current through a wire. It's normally cancelled because you have two wires in one package close together, sending the same current in opposite directions. Take some of the current and send it across ground, and they no longer cancel as much. That's EMI.

So, a faulty connection can cause resistance, which would make that happen. If you're lucky, that can be solved with the turn of a screwdriver. If you have aluminum wiring and regular outlets, or vice versa, that will definitely create such resistance. And where there's resistance, there's heat, so there's a fire hazard, especially if these issues are compounded.

But OP really needs to diagnose these things individually and specifically. A power conditioner is highly unlikely to have any appreciable effect at all. It's simply not possible to render a diagnosis over the Internet.
Old 6 days ago
  #15
Quote:
Originally Posted by kafka View Post
Anything that causes current to divert to the ground rather than the neutral will cause there to be uncanceled EMI in the room. Electromagnetism exists by sheer virtue of having current through a wire. It's normally cancelled because you have two wires in one package close together, sending the same current in opposite directions. Take some of the current and send it across ground, and they no longer cancel as much. That's EMI.

So, a faulty connection can cause resistance, which would make that happen. If you're lucky, that can be solved with the turn of a screwdriver. If you have aluminum wiring and regular outlets, or vice versa, that will definitely create such resistance. And where there's resistance, there's heat, so there's a fire hazard, especially if these issues are compounded.

But OP really needs to diagnose these things individually and specifically. A power conditioner is highly unlikely to have any appreciable effect at all. It's simply not possible to render a diagnosis over the Internet.
Your plugin tester won't tell you about faulty connections - it's an "all-or-nothing" device.

You'd need to be able to measure the circuit resistances with the power off, which the average person is neither equipped nor competent to do safely.

And that's still NOT a "ground loop".
Old 6 days ago
  #16
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kafka's Avatar
Quote:
Originally Posted by John Eppstein View Post
Your plugin tester won't tell you about faulty connections - it's an "all-or-nothing" device.

You'd need to be able to measure the circuit resistances with the power off, which the average person is neither equipped nor competent to do safely.

And that's still NOT a "ground loop".
Yes, this is all true. However, you can measure and locate EMF using a meter that costs about $25.
Old 6 days ago
  #17
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Originally Posted by kafka View Post
Yes, this is all true. However, you can measure and locate EMF using a meter that costs about $25.
PM me a link, please.
Old 5 days ago
  #18
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PM sent
Old 5 days ago
  #19
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Originally Posted by kafka View Post
PM sent
Thanks.
Old 19 hours ago
  #20
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Thread Starter
I really just want to know if a power conditioner or a voltage regulator or a sine wave inverter or an EHX Hum Debugger or pickup shielding is likely to help. I just tried a Furman SS-6B and it had no effect at all.
Old 10 hours ago
  #21
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Quote:
Originally Posted by lunaquesa View Post
I really just want to know if a power conditioner or a voltage regulator or a sine wave inverter or an EHX Hum Debugger or pickup shielding is likely to help. I just tried a Furman SS-6B and it had no effect at all.
No. They won't help. It's already been said. Pickup shielding could help, but most likely just a very slight amount, at most.
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