Dismiss Notice

Psst... Ready to join TalkBass and start posting, make new friends, sell your gear, and more?  Register your free account in 30 seconds.

Getting rid of AC line noise

Discussion in 'Recording Gear and Equipment [BG]' started by 12notes, Aug 21, 2003.


  1. 12notes

    12notes

    Jul 15, 2003
    Can the computer grade UPS with all kinds of ac line noise filtering capabilities cut down/eliminate line noises caused by dirty power in recording situation?

    Thanks.
     
  2. IMHO you won't get any benefit from buying a big UPS. A good power conditioner/surge protector, such as the Furman with EMI/RFI filtering, does just as well. A computer UPS is basically a surge protector with the aforementioned filtering, PLUS a small battery coupled to a circuit that will produce a pseudo-AC signal when you lose your electrical power. I say pseudo-AC because the AC isn't a sine wave when it's on the battery backup, it's an ugly looking thing. And the average UPS can't provide a lot of juice either.

    I use a power conditioner mostly for the surge protection. Most components now have a pretty good power supply section that'll filter out any hash coming down the line--basically, a few capacitors here and there. What I'm getting at: I really doubt dirty power is actually making its presence known, but since it is a recording situation, a good Furman is cheap--maybe $100--so get one since it's surge protection is beneficial. But don't waste money on a computer UPS, it's not intended for what you want to do.

    BTW,some people think they're getting noise coming in from the power line when it's actually just being picked up through the air by the equipment (amps, cables, guitars, mikes) acting like a radio tuner: there's lots of noise "transmitters" like fluorescent lights, air conditioners, refrigerators, neon displays, etc...Any time a large motor turns on, for example, a "pop" can be transmitted across the entire radio frequency band, and your equipment acts just likes a big antenna.
     
  3. 12notes

    12notes

    Jul 15, 2003
    Sorry for the late reply, and thanks for your reply.

    I know it's the AC line noise. I've been through this before, when I upgraded my tri-amped audio system. I solved the problem with a seperated circuit, wired with hospital graded wirings and sockets. The problem went away.

    I was asking about the computer USP simply because I can get a couplr 800 watts units for dirt, from my old boss.

    All my guitars and amps are very well shielded by myself. Not totally noise free. But much better than in stock forms.
     
  4. BassTerd

    BassTerd Supporting Member

    Aug 15, 2002
    Los Angeles
    From my experience I found the Furman power conditioners to be crappy glorified power strips that dont do anything to condition the power. I've been trying out a Powervar power conditioners. You can tell if you have a actual power conditioner if you pick it out and it ways a billion pounds. The conditioner i'm using works pretty good. It gets rid of a lot of crap I have in my shooty electrical in the house. I also take it with me to gigs because I been to to many clubs with shooty noisy electric. I've heard some users claiming the it improves S/N ratio. (whatever that is.)
    Heres a link: http://www.powervar.com/
     
  5. 12notes

    12notes

    Jul 15, 2003
    Yeah. I bought the Furman a long while ago. But I returned it after 30 minutes of trying it out.

    It's no better than those $10 for 2 power strips from Ikea!

    Over the years. I've found a lot of the famous name brand pro-audio, and home high-end audio gears are way over-hyped, over-priced junks. Many were good 30, 40, or more years ago. Many of them "earned" their reputations in the old days, when there were no, or very few competitions around. But when compared to many new, less well known, and more affordable new commers, especially many of the imports. Many old brands won't stand a chance in the real world.
     
  6. dpaton

    dpaton

    Jan 21, 2002
    Schaumburg, IL
    My money is that the difference was made by better grounding, not by the new wire for hot and neutral. Upgrading the current carrying wires (hot and neutral, black and white respectively) will have a negligable effect on the things that cause 'noise' unless they're so degraded that you're at risk for a fire. If there are big line transients due to large loads, a seperate circuit can help sometimes, but you're better off movin to a different location. Getting a good ground resolved almost every single case of supposed 'line noise' I've seen. That's years of live and studio experience talking.

    -dave
     
  7. 12notes

    12notes

    Jul 15, 2003
    The building itself is only 14 years old, and has been kept under good repairs. I think your suggestion is correct. I will ask one of my neighbour, who is a lisenced electrician, to help me check out the grounding.

    Thanks for your suggestion.
     
  8. dpaton

    dpaton

    Jan 21, 2002
    Schaumburg, IL
    It would also be helpful to know what kind of noise is the problem. Is it transient snaps and clicks? (Air conditioner, fridge, etc) Is it the bane of musicians everywhere, the dreaded hummmmmm (grounding), or is it something else (malfunctioning computer supply, wacky power grid, etc)?

    You've got me curious...

    -dave
     
  9. 12notes

    12notes

    Jul 15, 2003
    The noises are mostly like cracking and poping static noises. Sometimes, a fainted, but quite noticeable high pitched hum.

    My home is being kept at 45% humidity, and at 75 degree year round. So. Can't be statics.

    The situation is really a puzzling one here, because the noises only come on at some times, and not all the time, and not even everyday. But usually during the early evening hours. The time when I do most of my recordings.

    In some days. It can be totally dead silent.