Eliminating Interference and Hum

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dshlapak

New member
Hi there. Not exactly a newbie, but this is a dumb question. Bought an old but rewired house, and discovered upon setting up my gear that I'm getting incredible interference and hum everywhere--my mic is picking up a hip-hop radio station, and my Les Paul/Marshall combo is producing more buzz than signal. I've checked the polarity of the wall sockets and that at least checks out (mostly, and I'm not using the ones that don't). What can I do to exorcise all this friggin' noise? Better cables? Isloation transformers? The blood of a black rooster?

Any advice would be greatly appreciated. There are those who might argue that the static sounds better than my music, but what the heck--everyone needs a hobby, right?

Thanks.

Cheers.

--- das
 
man you have just stumbled into a HUGE area of this business. Totally open to debate and conjecture and very deep! Only Accousticians get paid more in this bizz than ground/isolation specialists. Theres lots and lots to read on this, I would suggest starting here:

http://www.benchmarkmedia.com/appnotes-a/caig/

now, their philosophy of choice " star grounding" is loved by many, hated by just as many, but its a good start
 
Howdy
I used a UPS to clean up the noise that I had in my equipment. APC makes a good one for about $50 bucks.
 
You have a "dirty" ground to your house. Also, probably radio/tv stations nearby. You must use shielded cables and supply a ground to earth. Most studios wire a ground from the main equipment (the mixer) to each ground pin on every single peice of equipment. Then, the ground wire needs to be connected to an iron rod staked into the earth. If all of your equipment has 3 prong plugs, you can plug them all into the same AC strip and gound the strip to the iron stake.
 
going off of acorec's post, a simple solution may be a 3 to 2 prong adapater. those have saved my life many times. also you may look at how you cable your mics. if you have huge coils sitting on the floor, essentially you have radio antennas sitting around your room. try to strch the cables out so that they don't lie on top of eachother or wind up in clumps.
 
Problems like this lend themselves to all sorts of speculation and possible solutions. The problem is that after you've tried all the "off the cuff" suggestions and still have the problem you could be out a lot of time and money, and be no closer to the solution.

Here's a few troubleshooting techinques that you can do yourself.

1 - Does the problem occur everywhere in the house or just in the room you're using to record. This should help you decide whether it's a systemic or localized problem.

2 - Do you neighbors experience similar problems with their televisions and radios picking extraneous crap? This will help you decide whether it's just the neighborhood you live in. Very unlikely...

3 - Do you have some other device in the house that is causing all your outlets to be noisy? Something like a really old refrigerator, ham radio, a blender that runs 24/7...

If this doesn't point you in the right direction, and if you can afford it, hire a reputable electrician. Discuss the process of elimination described above. If you can't afford one, cautiously ask around for advice from friends.

I say cautiously because people who tell you to do things like lift grounds (3 prong to 2 prong, etc) or drive new stakes in the ground probably aren't well schooled in safe and sane solutions.

I did like the idea of running a new circuit from the main panel and attaching all your studio outlets to it. Of course external interference might still nullify this.

Good luck. I chased this type of problem around for years while I was a radar technician in the USAF. Sometimes they just magically disappear and you never know if it was something you did or didn't do that fixed it.
 
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