Quote Originally Posted by ankietyjoe View Post
What I mean is, if nothing was connected to the soundcard inputs, what were you recording that had noise on it? Or is it just a background noise that's there all the time? Does the noise disappear if you disconnect the iO2?
Oh my bad. I just have the soundcard plugged in and recording a mono channel (channel 1) from the soundcard. There is nothing attached to the soundcard except it's USB wire being plugged into the PC machine so I'm recording nothingness. I'm doing it to see if the hum was coming from the mic, or preamp to rule those out. I tried both channels, and the hum persists.

Basically debugging to see what the cause could be.