Crackling amps

[damuncha]

Hi

I recently moved house and since moving in all my amps crackle. That includes a couple of Marshall valve amps, and some small park solid state. They were perfect in the other house but here they sound crap.

Is this something that anyone else has experienced?

It's driving me nuts!

[Mick Bailey]

Welcome to the forum.

Can you be more specific in what you mean by crackle? Do the controls crackle when moved, or do the amps make a crackling sound on their own with nothing plugged in, or do they only do this with a guitar connected?

What do you mean by "sound crap"?

[damuncha]

Hi thanks for the response.

I'm not 100% sure but I do think they don't make a noise when there is nothing plugged in. When guitar is plugged in all my amps now sound noisy. How to describe the sound is difficult. Hiss, crackle, buzz. When I touch the guitar strings or metal hardware the noise decreases. The noise is there for both clean and distorted sounds. Worse with distortion though.

I've checked all my cables and found them all the same. When I took an amp somewhere else (not at home) there was no noise.

I've read plenty of things that suggest issues with the amps themselves but not anything to do with the supply of power. I'm positive that there is a problem of some sort but I'd like to be more specific when I contact my electrician. I doubt that he's going to appreciate it when ask him to look at the electrics, he asks what the problem is and I tell him my amps make noises that they shouldn't!

[eschertron]

if I were troubleshooting what you describe, I'd take the smallest (easiest to handle) amp that makes this noise and carry it throughout the house, orienting it every which way, to see if there's a location and an alignment that makes this noise worse. If the interference only occurs with a guitar plugged in, turning around to make the guitar face different directions should be sufficient.

A thought. Does turning the lights on/off in any or all rooms change the volume or quality of the noise?

[Justin Thomas]

What kind of pickups are in your guitar?

Justin

[Chuck H]

These guys are on the right track. The real clue is that you don' get noise when nothing is plugged in. The noise is likely getting into the signal chain through the pickups on your guitar. Hopefully you can locate and change the circumstances in your own home. There are instances where such noise is coming from local business or industry and then there isn't much to be reasonably done.

[Justin Thomas]

I live in a city, in a house with 20 people (and their associated gadgets). I play a Tele with standard single-coil Duncans. RARELY does my guitar make ONLY guitar sound. I pick it up if our multiple large appliances kick on, when several people are making heavy-duty WiFi use, all of the electromagnetic "noise" (clicks, chirps, squawks, buzzes, hums, crackles, etc.) associated with a wireless society. I can mute some by keeping hands on the strings (as you can), and most of the rest I can eliminate by turning my guitar to the right position. Sadly, that's usually at a VERY awkward angle and body position. Some days, it gets so bad I quit playing.

Other times I have crackles are when my instrument cable has the ground shield just BARELY touching the inner conductor, it only has to be a strand or two. It will get better or worse if I wiggle the plug ends, or else it's a short in the middle, in which I check inch by inch and then turn my single long cable into two...

Be thorough, be systematic, and break it down. It's not a black art, and there IS an answer.

Justin

[Mick Bailey]

A customer bought me his Mesa combo - said it was buzzing loudly. I was pretty busy and didn't have chance to check it while he was here (I usually get the customer to show me the fault). After he'd gone I tried everything I know to get that amp to buzz. Along the way I fixed the broken reverb and the channel switching that didn't work.

Anyhow, he took it back home and rang me back. He was pretty angry and insisted he bought it back that night. We plugged it in and no buzz. So he took it back home and held his phone against the amp. It was pretty loud, but when I asked him to turn the guitar down, no buzz. I asked him if he'd got any dimmers etc, but he hadn't. He then told me it only started after he'd had some electrical work done. Pity he didn't tell me that in the first place. He then contacted his electrician who came back and found an earthing fault with his mains wiring. Fixed that and no more buzz.

In another instance a guy had a CF (Compact Fluorescent) lamp near to his amp causing buzzing. My laptop causes noise as well as my DECT phone, lamp dimmer, and 12v spot lighting.

[olddawg]

Cell phones, fluorescent lights, wifi, computer power supplies, refrigerator, triac dimmers. All can do it. Just hope your neighbor isn't a ham radio enthusiast or has a CB with a linear amp! Lol.

[Jazz P Bass]

In the winter time I have a 'space heater' that will induce noise.

Triac dimmers are the best.

[nickb]

And, curiously, all these products are required to pass stringent Electromagnetic Compatibility tests at very considerable cost. A cost that is added to the end price...

[Justin Thomas]

Nick,

I'm pretty sure the FCC only means they can't interfere with the "important" stuff, like airlines, EMT comms, and TV & radio. Guitar players? What the he'll are those? We were told rock was dead 3 decades ago!

More seriously, I think all the rules say they can't EMIT "harmful" radiation, but they always have to ACCEPT it. Which to me is basically them saying, tough cookies... besides, this is America. Regulations are bought, not enforced.

Justin

[rjb]

I'm pretty sure the FCC only means they can't interfere with the "important" stuff, like airlines, EMT comms, and TV & radio. Guitar players? What the he'll are those? We were told rock was dead 3 decades ago!

Guitar players are such whiners.
They insist on running high impedance signals through unbalanced cables, then cry when they pick up a little interference.
Like, dude, what did you expect?

http://www.lutron.com/TechnicalDocum...ary/360484.pdf
Recommendations
Lutron recommends the following methods to avoid RFI.
• Feed sensitive equipment from a circuit without a dimmer on it.
• Add a power-line filter to the sensitive equipment. (Power-line filters may be purchased at most electrical suppliers and distributors.)
• Use shielded wire for all microphones and input cables. Also, use low-impedance balanced microphone cables,because they are less susceptible to interference than high-impedance cables.
• Make sure all equipment is grounded. Connect all shields to ground at one point. Ground lighting fixture metal housings properly.
• To filter the RFI, use a lamp debuzzing coil (LDC) available from Lutron. Refer to the next page.
Note: The suggestions in this application note will help minimize RFI; however, they do not guarantee that RFI will be completely eliminated.

-rb

[Enzo]

SHielded cable is a must, but the pickups themselves will still pick stuff up.

If you interfere with people's TV reception, the FCC frowns on it, but if you interfere with AM radio, they won;t care at all. Well unless it is egregious .

And of course, never interfere with essential services.