Thanks for the reply. The noise is heard in whatever I’m using to monitor the recording (speakers or headphones). It is heard during the recording and is in the recorded clip. Like I said, the noise appears when I “arm” a track for recording in Soundtrack Pro. I tried Audition and get the same noise as soon as I arm a track. When I disconnect the audio inputs from the UCA202 the audio from the booth cuts out (of course) but the noise remains. Disconnecting the UCA202 makes the noise go away.