Static noise connecting DAC via toslink

Ejlif - I agree. Something else is wrong. Toslink is notorious for jitter and while jitter is noise (in time domain) it shows only when signal is present. With no signal it should be quiet.

Ajackson1 - Jitter creates sidebands not harmonically related to root frequency and therefore audible even at low levels. With a lot of frequencies (music) it becomes noise on the top of the signal. It usually shows as a lack of clarity but if you can hear pink noise then it has to be something else. Double check setup on your MAC Mini

http://www.sixmoons.com/audioreviews/toslink/toslink.html

Tsugury - According this article they tested cables with device (Bel Canto DAC2) that completely (over 100dB rejection) rejects jitter. Bel Canto DAC2 is based on AD1896 - same upsampler used in Benchmark DAC1. Benchmark tested DAC1 with about thousand feet of cat5 cable instead of coax and could not tell the difference http://www.posthorn.com/Bench_5.html

Mentioned in sixmoon article modern dual PLLs used in CDPs don't even come close to rejection of AD1896. It would be nice to read article that makes sens - test with regular oversampling DAC or NOS DAC where good cables are needed (but not asynchronous upsampling jitter rejecting DAC).

Ajackson1 - I found on Apple forum similar problem:
http://discussions.apple.com/thread.jspa?messageID=9476112

It looks like Mac Mini removes carrier (red light) after 30s with no signal and some receivers don't like it generating a lot of static. It is suggested to find a way to keep optical port open all the time on MAC Mini. I hope it will help.

Thanks guys really appreciate all the feedback and suggestions.