Paul Neyrinck discusses how to use the Macbook/iMac/Mac-mini optical digital audio output (minijack)

Every MacBook/iMac/Mac-mini sold the past few years has an audio output that is specified as a “headphone/optical digital audio output (minijack).” See here, for example. Recently, I wanted to use this digital audio output to connect to my living room home theater receiver but found very little information about it. I called two Apple stores in San Francisco and neither Genius knew about the feature and could not explain how to use it or buy cables for it. In this post I share what I learned after much online research and experimentation.

How It Works
From the outside, the minijack output looks and behaves like any tip-ring-sleeve analog audio minijack. And the Sound Output panel in preferences does not indicate anything otherwise (my Macbook Pro names the output “Internal Speakers”.) But deep inside the minijack is an optical output circuit that is not operational or visible until you insert a special plug. You must insert a special plug that has a little hole on the end that goes deep inside and receives the optical light source. Wikipedia calls it a mini-TOSLINK. Amazon sells adapters and cables that call it optical mini. If you insert this special plug, then the Mac detects it and magically changes the name of the output in the Sound preferences panel (my Macbook Pro changes the name from “Internal Speakers” to “Digital Out.”).

Getting The Cable/Adapter

Radio Shack does not sell them. Best Buy does not sell them. And interestingly, Apple does not sell them online or at the retail stores. Apple used to sell a Belkin cable/adapter but apparently stopped as far as I could tell. Thank goodness for Amazon who sells a few different cables and adapters. But most amazing is the price. For example, they sell a 6 Foot Toslink to Mini Toslink Cable for 51 cents. I bought a 6-foot cable and a 12-foot cable for just a few dollars.

Using It For DVD Surround Sound

The Mac DVD Player application has a preference for audio output. Normally, it just says “built-in output” on my Macbook Pro. But if I connect the mini optical cable before launching DVD Player, the preference has an additional choice called “Digital Output.” And when I connect to my home theater receiver, I can listen to 5.1 Dolby Digital or DTS soundtracks. So now I am looking into a Mac-mini as a home theater playback system for files and DVD’s…more to come.

I hope this information can save someone time figuring out how to use this nifty feature available in millions of Macs.