Stuttering Digital Out on MacBook Pro

This saturday I decided to connect my 2010 MacBook Pro to the 5.1 reciever to watch mkv videos. After doing some reading i figured out that I needed a mini displayport to HDMI adapter for the video and a TosLink + a 3,5mm adapter for the optical output hidden in the headphone port on the laptop.

Checking out some stores in Stockholm it all would land on somewhere around 600 SEK (~60€). Quite a hefty price tag for two cables and in addition to that I had to visit two stores since neither had both the adapters in stock. On the way to the store I figured I should check out this radioshack-type-store called Kjell&Company; where I to my surprise found all I needed for about half the expected price. Woho!

When I came home I connected the laptop to the receiver, fired up VLC to watch the videos and configured it to pass AC3 and DTS through the digital cable instead of decoding it. The receiver directly understood that there was 5.1 audio sent through the optical cable but once every 20 seconds or so it lost the signal and there was a short silence introduced. It was extremely annoying and unbearable so to live with it was not an option.

I sought all over the net (apples forums, vlc forums), tried every configuration parameter in VLC that could affect the sound, tried MPlayer, tried XMBC but nothing solved the problem. I tried to enable passthrough of audio directly from a DVD with the apple DVD player but got the same problem.

It turns out it was the cheap TosLink cable that was the problem. I had another device connected with a bit more expensive optical cable and switching the cables solved the problem. Hopes this helps someone having the same problem.