I have a Lite DAC-Ah with my Odyssey Etesian/Khartago/Nightingale system that takes Digital optical output from an Airport Express. The whole system and sounds awesome when playing Apple Lossless files.
The thing I have noticed though is when I'm not running a signal to it if I turn up the pre-amp it is pretty much silent (no-hiss or other noise) but every few seconds there is a high pitch whine for about a second and then it stops. I thought it might be something in the power line but when I flick the select switch from the optical to the RCA the sound is there constantly.
I should be clear this sound is not very noticeable and certainly can't be detected during playback but knowing it is there is bugging me.
Any ideas on what it is and how I might cure it?
Jim.
