Can't get rid of hum

[ngaruawahia]

Would love it if someone can help. I'm recording spoken voice only onto my laptop, coming out of a little Tube amp made by ART. Nothing terribly high-tech. But I can't get rid of an audible hum. I'm have a mic cord going from the pre-amp and am connecting it to the laptop with a little adapter plug.
Any ideas how to get rid of the hum? It wasn't there last time I recorded. It has come but gone in the past. Now it seems determined to hang around. Thanks so much in advance. Ngaruawahia.

[dentldir]

Sounds like a ground loop hum. If you do a frequency analysis on the hum is it centered at 60Hz? If so, try plugging the power supply from the ART and the laptop into the same power strip and see if it helps. If not, try running the laptop off the battery and see if that makes a difference. If that doesn't do it, then try and find a Hum-Eliminator by Ebtech. Those little isolating transformers have saved my studio from all kinds of hum.

If nothing else works and you need a $0 solution, then capture then hum as a noise profile in Audition then noise reduce it out of the way after you are done recording.

Good luck,
Rafael

[rgrant1741]

I had a hum problem connecting my computer sound card to my HDTV. The hum was that tell tale sound of a ground loop - 60HZ. I never would have believed it, but I gave it a try. The ground loop hum is gone. $16.99 is the standard price. Hope this helps.

[fortyseven]

Yes, get a ground loop isolator from Radio Shack; they're real cheap.