How to rid house circuit noise in amp?

[Butch Pytko]

In my home music room I'm getting circuit noise in my amp only when I have the main overhead light on. This happens with my guitar that has single coil pickups--doen't happen with my other guitar that has humbuckers. It just so happens that I need to change the overhead light, in order to get better lighting. Since that circuit is making the amp noise, is there some kind of specialized light fixture that prevents noise in amps? I guess like what the recording studios use. I have a fluorescent light fixture picked-out, but aren't they notorious for causing circuit noise? Also, I've seen a noise/filter/suppressor type thing at Guitar Center, that's supposed to eliminate circuit noise--would that be a better way to go? Thanks.

[Rich Hlaves]

Any light fixture with a balast may introduce hum into your signal so I would stay away from florescent fixtures and stick with incads.

You might try a "Hum X", they get good reviews around here for nocking down the noise. You might also want to test your grounds while updating your lighting.

My living room is noisey as hell. I've checked everything and all is well so I live with it.

[Sidney Malone]

Not sure what kind of light switch you have but a lot of "dimmer" switches can cause noise even with regular light bulbs. The dimmers normally work fine on full brightness but it's when you dim the lights that the noise can start.

I personally prefer a standard on/off switch with regular old light bulbs.

[David Collins]

FWIW:

Most newer fluorescent fixtures have "electronic" ballast as opposed to the older version "magnetic" ballast. The electronic ballast create virtually no noise. The magnetic ballast certainly do.

[Lynn Oliver]

Shielding the pickup cavities in my Fender Deluxe reduced the noise problem significantly.

[Dave Grafe]

First of all, forget the guitar center gizmo, the only thing it will remove is cash from your wallet.

There are a couple of different ways that lighting circuits can generate noise in guitars: As previously mentioned, airborn magnetic interference from voltage spikes created by flourescent lighting ballasts is a common offender, as are spikes in the line voltage induced by lighting dimmers and/or wall-wart power supplies. Some electrical motors will dirty up the power also and incandescent lightbulbs themselves can be a source of noise but only if they are very near the guitar or the fixture itself has a bad connection.

As you have already discovered, humbucking pickups cancel this interference out but single coils celebrate it!

[Butch Pytko]

Guys, thanks for the comments, so far. No, I don't have a dimmer--just the standard on/off switch. About fluorescent fixtures, it does make sense that today's fixtures would be noise-free--I may go ahead & try the new fluorescent one I've got in mind. That paricular circuit is the only one that has noise--during the day, that light is off, so, no noise. Concerning the various anti-hum/noise devices. I did a search on the internet & discovered a review written by an electrical engineer on this very problem. He explained in easy to understand terms that house circuits were not designed to eliminate circuit noise, unless specifically designed to do so. The only thing that electrial contractors were concerned about, was to conform to local electrical codes. He claims the only way to rid the noise is to utilize a huge mega transformer type filter. His description of it is way too involved to explain it here. But, he pretty-much put down the mini filter devices, claiming they are useless. So, I'm not sure my problem is solved over-all, but if I install a new fixture & it happens to be noise-free--I'm in the pink!

[Bob Hoffnar]

I solved a problem like that by running an extension cord from a different circuit than the light to my amp. Worth a try.

[Randy Wade]

Put you a GeorgeL pickup in there and say goodbye to hum

[Clete Ritta]

...is there some kind of specialized light fixture that prevents noise in amps? I guess like what the recording studios use...

Some studios have power to the lights on a different leg.
If dimmers are used they are often the variac type (large and heavy).

Distance from fluorescent lights and fans is a factor.
Move the light (if possible) and amp around the room.
Listen for the spot that produces the least interference.
Those single coil pickups can act like an antenna!

Perhaps a power conditioner may help isolate your amp power source.
Also noticed youre in the Lightning Capital of America so,
Make sure youre grounded
Good luck.

Clete

[John McClung]

I recently installed two fluorescent overhead shop lights in my practice room, dual T-8 bulbs in each fixture. I was shocked, they come on instantly and are dead silent, I didn't know things had improved so much in recent years in the fluoro lighting realm!

I still get what seems like random distortion occasionally from my house AC, anyone know how to test that and remedy the noise problem? It comes and goes, might even be a piece of gear in my rack.

[Dave Grafe]

Random noise in the line is quite possibly back-feed from an electric motor or other intermittant device such as a refrigerator, air compressor, furnace motor or igniter circuit, either on your premises or that of a neighbor.

[John McClung]

Dave, any way to filter that out?

[Dave Grafe]

You might try a different circuit, if the offending device is 110 VAC the opposite side of the service should still be clean.

[Max W. Thompson]

I wanted to ask this same kind of question. Can the polarity in the light fixture make a difference in the amount of noise in the guitars? I have always had noise from the overhead light in my music room. My old guitars all have single coil pickups, and when that light is on, the noise level is unbearable. When I replaced the fixture, it was still there. I thought about reversing the wires on the light fixture, to see if they were originally wired wrong, but wasn't sure this would make a difference in an ac circuit. I can't tell if the wires up there are right or not because the cloth (yes, cloth) insulation has no color coding.

So, will switching the wires on the fixture make a difference in the noise?

[Dave Grafe]

In an AC circuit both wires change polarity constantly and in a balanced fashion so no, changing the wires will make no difference. As such there is really no "right" or "not right" way to hook them up to a light fixture in terms of polarity, although NEC specifies that the neutral side of the circuit should be connected to the outer, threaded part of an incendescent lamp socket.

Again, noise in guitar pickups is ENTIRELY from ambient magnetic fields in the environment, whether from lighting fixtures, heaters, motors, current supply lines, transformers, SCR dimmers, radio-telephone devices, cosmic rays or a number of other sources. Various grounding and shielding schemes can reduce the proliferation and impact of such magnetic interference and "hum bucking" pickups can provide a high degree of common-mode rejection but our beloved single-coil guitars will by definition and design always pick up and transmit every magnetic disturbance that they encounter.

It's not uncommon for equipment at a neighboring location to leave nasty artifacts in the power of an entire block or more, like local dimmers the spikes become radio waves that are picked up by our guitars. If you have access to a scope and know how to use it you can look at the waveform of the supply AC at various circuits in your home to see if there are chronic or intermittant spikes in the lines both when your home appliances (refrigerator, stove, furnace, lights, etc.) are and are not in use. If you have dirty power when all of your household stuff is turned off - this includes making sure that ALL wallwarts are unplugged - then there is not a thing you can do about it, really. If, on the other hand, you are able to clean up the power by unplugging one or more devices in your own home then once you have identified them you have just solved your problem.

[Glenn Uhler]

If you suspect your guitar is the problem, here are a couple of things you can do to cut down the hum. 1. Get some thin metal foil (copper or steel) and line the bottom of the pickup cavity with the metal. After you install it, you also have to ground it. Run a seperate ground wire to the base of the amp jack. 2. Ground the tuner head casting to the amp jack. Sometimes, the ground connection to the strings isn't too good at the changer end due to a grease or oil film between the fingers and the axle. Same with the rollers on the tuner end. Install a ground wire between the head casting and the base of the amp jack.

[Ray Minich]

Noise is introduced into a circuit by radiation and conduction. A good 1 KVA Constant Voltage Regulated transformer could solve the conduction problem, but they cost about $1000. Radiation (Electromagnetic Interference) requires shielding and EMI source eliminiation.

If the power line to your house has the noise on it already, filtering it is not trivial.

We had a factory nearby that used some high power SCR systems to drive an electrocoating operation. The spikes those SCRs put on the powerline propogated back down the feeder mains for several miles.

[Bill Ford]

We used to put foil under the vol pedal. Don't remember how well it worked tho. I think it worked OK, cause everyone did it.(back in the old days)LOL

Bill

[Whip Lashaway]

If you have a good local electrical supply source, you might get a 1:1 isolation transformer. Since your home and using this room all the time just isolate that whole circuit. Haven't priced em lately but I used to get them for under $100.00. You probably wouldn't want to do it on-line as they are heavy and shipping would kill you.

[memphislim]

Your cell phone any where near can also cause quite a racket.

[Mike Perlowin]

Would one of those Furman Power Conditioners help?