I recently purchased a used Digital Lens and also became aware of occasional non-musical sounds. I hear an occasional "tick" that almost sounds like a small scratch on a black vinyl record during music. A bit more disconcerting is a rather loud pop that occurs near the beginning of each cut. I suspect that these anomalies may be caused by the periodic emtying of the buffer in the unit. The owner's manual makes reference to this function, although it doesn't tell you that it may be accompanied by noise. I assume it's natural for the buffer to empty as each new cut begins. Prior to using the Digital Lens, I was using an Audio Alchemy DTI and heard none of this, so it almost has to be caused by the Lens, as opposed to some other component in my system. Nothing else has changed.