4 Replies Latest reply: Oct 24, 2013 3:52 AM by MilGra
pgm234 Level 1 Level 1 (0 points)
I recently bought a Mac Mini (4GB RAM) to play FLAC and ALAC files into my stereo system. But I have run into a problem.

I have played FLAC and ALAC files using Songbird, VLC and iTunes. I am feeding the digital audio out from the Mac Mini via Toslink to the digital audio input on the back of my pre-amp.

The problem is that as each song finishes in a playlist or during an album, there is a 1-3 second break in the audio input. This is evidenced by the L/R input indicator lights on the front of the pre-amp going out (like the input signal was temporarily lost), but more importantly by the first second or so of the next song not playing. The lights always come back on but I've missed the first second or two of the new song.

I am using other Toslink audio inputs into my pre-amp from my DVD player and Cable TV box, both with no problems.

I have tried changing out the Toslink cables and switching the Mac audio output into the other 2 pre-amp Toslink inputs with no success.

Also, I tried a 3.5mm-to-dual RCA jack splitter and ran the analog audio out from the Mac Mini's headphone jack and the break does not happen and the new song plays fine right from the start. (the input lights stay on on the pre-amp while one song ends and the other starts).

I have tried different software audio players (iTunes, Songbird, VLC) and this happens with all 3. I have also tried both ALAC and FLAC files, which play fine on another computer (i.e., the song files definitely are OK).

I have tried playing with the gapless and crossfade settings in iTunes but I think the issue is with the digital/optical audio out from the Mac Mini or it could be how my pre-amp is handling the audio input via Toslink.


Mac Mini, Mac OS X (10.6.5)
  • Dah•veed Level 7 Level 7 (32,495 points)
    The digital audio goes to sleep soon after an audio source goes silent, but this is the first complaint of the issue that I have seen where it is reported to do it within 3 seconds!

    Google around and you may find a little app to keep digital audio on a Mac awake. SoundOn and KeepSound Awake were two in the past.


  • TheDude Level 1 Level 1 (5 points)
    I've got the same issue with my HTPC... (mid '09) Mac Mini > Toslink > NAD amp
    Every audio source has a half second or so 'hiccup' in the beginning. Even if iTunes (or whatever) was just playing a previous file. It is like the sync is released and then re-established based on the file's usage (not the program).
    Adding a cross-fade setting in iTunes seems to help, but that doesn't help in the least for editing (which I do a lot of).
    The analog output really is inferior to the optical (especiallt if you have a good DAC), but if you can't hear it what's the point?
    I haven't found any scripts that work for my 10.6x Mini yet...
  • DCGoD Level 1 Level 1 (5 points)

    I went ahead and wrote a simple app to fix this issue in OSX Lion as well as previous versions. It's called Silent But Deadly.


    Same concept that you may have heard of before in the past; play a short audio clip that's just loud enough to activate the Toslink SPDIF port but still soft enough to not be noticable. The app will automatically lower to the dock and utilizes <1% cpu usage on most machines. Bloatware, Malware and Virus free. 








  • MilGra Level 1 Level 1 (0 points)

    This problem really bugged me also, so I had to write something that keeps the optical audio port alive with the lowest impact. The best solution was an AudioQueue-based tone generator, which generates a 20 hz pulse with the lowest pulse level, silenced to 1 percent. It's absolutely unhearable on my LG home theatre system with all volumes maxed out, so I'm quite happy now.


    I've just released the app on the mac app store, it is called Optical Audio Port Keepalive .