Interference..

[warlok]

Figured I'd start a different thread for this. I'm getting a buzz through my amp that is (almost) definitely interference from something but I don't know what. New tubes in the amp (Peavey Ultra Plus). Almost not noticeable on clean, louder on crunch, even louder on ultra. Does it with every guitar and they're all shielded. No monitors, flourescent lights, or anything around me where I'm playing in the house. Upstairs, in the corner of the house, not near anything. It completely stops if I unplug or turn the volume down on the guitar so I'm fairly positive it's not the amp itself. So don't know what the scoop is. I did notice that if I flip the switch on or off on the ceiling fan, I hear the click/pop through the amp. Could it be picking up something from the house wiring? Maybe need a conditioner or UPS or something to plug into? I'm lost here now.

[Spivonious]

Does it happen in every room, or just that one? Is it still there if everything else in the room is turned off?

[DonP]

Does it happen with the amp turned on, set fairly loud, guitars not plugged in?

If no, it's not the amp, it's the guitar, or the guitar cable. Get a high quality shielded cable to rule that out.

[lerxstcat]

The amp is fucked, and dangerous! You should ship it to me and I'll dispose of it properly since I live in Mississippi, the Peavey State!

You're welcome!

[warlok]

Does it happen in every room, or just that one? Is it still there if everything else in the room is turned off?

I haven't moved it to another room but the room I'm in is 35'x20' and ive tried 6 different spots in that room in 4 different plugs. And i've turned everything in and around the room off. Even turned everything downstairs off.

Does it happen with the amp turned on, set fairly loud, guitars not plugged in?

If no, it's not the amp, it's the guitar, or the guitar cable. Get a high quality shielded cable to rule that out.

No. quiet with nothing plugged in and amp cranked. Tried 7 different cables. 2 say "shielded" on them. All sound the same.

The amp is fucked, and dangerous! You should ship it to me and I'll dispose of it properly since I live in Mississippi, the Peavey State!

You're welcome!

That's my next plan... :idea:

What to check next? I'm lost!!

[Trem]

warlock,
you may not want to hear this but i'm about 90% sure it's your shielding.
the reason i say this is because i think you asked before about shielding before you got this amp and if so then you already had the issue.

i had the exact same thing going on, not just with my peavey but also with my mp-1 at home, i finally narrowed it down to either my furmans (which they do actually create some interference to a degree, both of them in different places, (different cities, different buildings.) or my guitars, or some shitty electrical happened to be everywhere i go.

if you didn't read up on how to shield properly, and just put some shielding in your control cavities and called it good, it is most likely not right.

if you don't have any light dimmers in your house (which can cause interference) then your shielding should be rethought or redone.

firstly, you need a multimeter and better yet one that can make a noise when there is continuity. you can get one for under 20 bucks.

your shielding tape if that's what you used, needs to fully connected to each other from each cavity you shield. usually with a piece of wire.

just shielding your control cavity (like on a back routed guitar) is usually not good enough.

more importantly, your pickup cavities and jack cavity (if possible like a dish type jack) should all be shielded and connected with a piece of wire to each, so that with a multimeter you can touch one probe to one cavity, and the other probe to another cavity and have continuity.
if not, your not shielded.

also the other main factor is your soldering, if it's not a good joint, it can help to create noise - if these conditions are not met, you can actually have more buzz than ever.

I was not successful on my first and second attempt either and i did everything right as far as i could tell, had continuity et all, however i resoldered some questionable joints and then there i had it.

you will know when you have it right because i can almost guarantee that
your guitar will be silent. it will make normal tiny bit of line noise, and when you touch the bridge it will be dead silent.

i didn't even bother reattaching my floyd and strings, just plugged it in to test and touched the claw in the back cavity, you can hear if it's worked or not.

by he way i replaced all the wire and pots, switches when i did it.
i got some 4 conductor shielded cable from fry's, it also has a 5th bare wire
to use as ground, i ran that (RR1) from the jack to the control cavity, with the bare wire connected to the shielding in the jack cavity, to the shielding in the control cavity, also i ran another regular black wire from pickup shielding to pickup shielding into the control cavity.

as far as pickups and pots, just make sure you wire them correct, and don't have a mess of wire stuffed in there, just use lengths you need, maybe a pinch extra for breathing room, ( i actually twisted all mine) connect all grounds (not the shielding grounds) just the electrical components grounds to your volume knob.

the biggest noticeable change came from shielding my pickup cavities and jack, because at first i just tried the control cavity, and then checked it to see incremental changes, it was those two things that really made the difference.

i can sit right in from of my 24 widescreen crt triniton tube monitor and
it is quiet more than i thought was possible, where before it was like a electrical tornado.

anyway, good luck -



Something i forgot also, if you have shielded your jack cavity, make sure that when you plug your cord in the tip does not make contact with the shielding
else you will be hearing mega buzz.

[vondran]

If it goes away when you turn down the volume on the guitar and is the same on any guitar, it's likely a grounding problem.

First, if your amp has a ground switch on the back try it in the varioius settings.

Second, make sure your wall plug ground is actually ground. A 3 prong socket doesn't mean the ground is connected up right, and a lot of older houses are not wired correctly. You can pickup a cheap outlet tester at home depot for a few bucks.

Third, make sure you're not creating a ground loop somewhere. If you have any effects or pedals running off a power supply make sure they're plugged into the same outlet. If you split your signal anywhere in the chain (i.e. run amps in stereo) unplug those and see if it goes away.

[BallooTheBear]

When I lived in New Orleans I had the same problem with all my amps.19?? whatever apartment.I had to use a three prong adapter which is not a good idea,didn't solve the problem but I could play anyway.Moved back to VA in a much newer apartment and now the problem is solved.I knew it was a ground problem,I should have bought a crappy practice amp but instead when I moved back I had to send my Mesa to the shop for strange crackling noises(tubes had been replaced).Obviously I had messed something up for cranking it without a proper ground for all those years.One of those DOH moments.I sir was an idiot.

[warlok]

i think you asked before about shielding before you got this amp and if so then you already had the issue.

Hey Trem. When I asked about shielding, I was getting ready to wire the M6 and had aluminum tape so wanted to see if it was OK instead of copper. Answer was yes so that's what I used. So I didn't have an issue, just seeing if it was ok to use the aluminum. And it's really think tape too. Before I did anything, I checked all the cavities to see if it had shielding paint, and it had continuity all the way from the jack to the last pup cavity. Then I shielded the rear cavity (electronics). I didn't do the pup cavities cause the pickups sit very low and you'd see the tape but with the paint and wire grounding the cavities, I figured it'd be fine. Then I put the ground wire harness back in that screws to all of the cavities. Then wired with all new pots, pups, and jack. All grounds go to the vol pot except the cavity ground wires. I know the solders are all good. I'm an aircraft mechanic and have been soldering for a long time so I'm positive they're all good. The only thing I haven't tried is to see if there's ground all the way to the outside of the jack. I didn't shield all the way into the hole for the jack. But I'm sure the paint goes all the way into there. I'll check that.

First, if your amp has a ground switch on the back try it in the varioius settings.

I forgot about that switch, I'll try it. Other than that, my house is only 5 years old. Bought it new. Although I can't guarantee that the builders or inspectors did the job perfect, I've never had a problem and assume it's all to code... And I've taken the efx loop completely out of the mix and unplugged from wall. Didn't change. And it's just the 1 amp, no stereo.

I'll check the jack cavity and ground switch and see what happens but I'm not feeling confident at this point.

[vondran]

If that doesn't fix the problem, it's likely you just have a lot of electro-magnetic noise in your house. Typically humbuckers are pretty good about filtering out the 60 cycle hum. But if your house is near high power lines, radio towers, etc., it's just there.

I had a co-worker years ago that was into HAM radio and had a tester wand that he could identify items that were putting out noise. He told me he would go to his neighbors houses and locate lamps, toasters, computers, ... that were acting as nice antennas. He would wrap their power cords around a small iron rod to isolate them. He said that his neighbors were appriciative as suddenly their TV reception got much better. If you happen to know of anyone that is into HAM radio, they may be able to help.

[CKJ]

If you have your reverb turned up on your head/amp try turning that down to see if it goes away. I get a buzzing noise whenever I have the reverb turned up above anything but 0 (go figure) on my Crate head so I just use the reverb in my effects pedals.