Re: hum cancelling

[kflint@annihilist.com (Kim Flint)]

>I'm having continuous problems with humming. With my setup slowly getting
>more elaborate and containing more devices and cables, it's getting worse,
>and I'm already at the point where the humming is so bad I can't do any
>recordings at home which are good enough for publication. I would love to
>get one of these new 8-track disc recording machines, and make my own
>CD-ready recordings, but as long as there is audible humming no matter 
>what
>I do, this wouldn't be worth it.
>
>Any general ideas what to do about this? Simply turning around the cables
>doesn't seem to help. Is there hope at all? Is it possible to run a heap 
>of
>devices (2 computers, recorders, tuner/amplifiers and CD players, an old
>Minimoog, sampler, DAT, loop delays, volume and other pedals, Vortex,
>guitars, reverb) connected by a jungle of cables, without having any
>disturbing hums? There's not enough space and I can't afford setting up
>a professional studio in my room.
>
>-Michael

It's possible to fix these problems, some ideas off the top of my head:

1. Make sure you have isolation washers on all your rack gear so you don't
get ground loops through the rack.

2. Keep all the audio cables as seperate from the power cables as possible.
If they must cross, make sure they are perpindicular.

3. Make sure all your audio cables are good quality and have a shield. Use
balance cables when you can.

4. Computers, and especially monitors, are likely to cause hum, try to keep
some distance between them.

5. keep cables as short as possible.

6. Try to create a star ground, where you start from a single outlet and
create a star of power/ground lines coming out.

7. DON'T PULL THE GROUND PINS!!!!  People often try to solve hum problems
by lifting the grounds. This is dangerous, don't do it! You can get shocked
this way.

8. If you still have a problem, try taking things out of your system one at
a time to isolate the source of the hum. If you find it, try moving it
elsewhere to seperate it from the other stuff.

9. Don't use flourescent lights or dimmer switches.

hope this helps,

kim

______________________________________________________________________
Kim Flint                   | Looper's Delight
kflint@annihilist.com       | http://www.annihilist.com/loop/loop.html
http://www.annihilist.com/  | Loopers-Delight-request@annihilist.com