Hires audio playback direct from iTunes/Mac?

[daveloc]

It's moderately well-known that iTunes will store and even transcode stereo music data in WAV, AIFF, and ALAC formats at much higher resolutions than CD — many iDevices won't and will refuse to sync such files, but they still play in iTunes itself (or other QT-based players), so if you create and/or upsample a track at say, 16/88.2 or even 24/176.4KHz, you can import, annotate, and play it through either the internal speakers or those attached by a minijack port.

According to Mac Help you can also play "HD audio" on HDMI devices such as TVs and AV receivers either via the HDMI Out of a modern Mac Mini, or a HDMI adaptor on DisplayPort/Thunderbolt.

Can anyone confirm that DRM-free PCM audio output this way reaches the target device without decimation and/or copy protection, or whether it is necessary to adjust Audio MIDI Setup to get it to work? I'm only interested in PCM stereo FTTB, although if PCM multichannel and or hires Dolby/DTS do/don't work, it would be nice to know for future reference...

 

[iMark]

I can confirm that iTunes/QT will output hires through optical. I have tried this by connecting my MacBook to my DACMagic. I have a few hires albums from B&W and I converted the FLAC to hires AIFF. The DACMagic recognizes the stream as 24bit.

There's a lot more info about this on http://www.computeraudiophile.com/

I have so few hires files that I don't use this option. In our setup it is much more convenient to use an Airport Express near the stereo and not have long Toslink cable through the room. To be perfectly honest the sound quality of Apple Lossless through the DACMagic is so good that I have stopped dabbling with hires.

 

[Anonymous]

Unless you select the specific sample rate in 'AudioMidi' ITunes will upsample or downsample everything to 24/96 , I prefer to play every file in it's native format, there is playback software available which senses and automatically changes the sample rates
Optical from a Mac is limited to 24/96 , FireWire and USB are not limited.
Keith.