UA-1X: SYMPTOM: Audio not registering in Felt Tip Sound Studio on iMac.

Tags: sound,studio,ua-1x,imac,noise
The UA-1X has uncovered a noise issue, which is actually a bug in the Apple Core Audio driver. This issue is fixed in Core Audio in OS 10.3.3.

You may want to try Audacity, a free application, that is known to work with the UA-1X: