Airplay music streaming and internal DAC bypass

Question

Hello everyone, I'm an "audiophile" who loves high quality liquid music, and I need help about Airplay hi-fi music streaming.
I own an Apple TV 3gen linked with optical cable to my stereo amplifier internal hi-end DAC for optimal sound quality. Everything is fine when I play my iTunes network shared music using the Apple TV iTunes app or computer shared libraries, because the digital file is directly sent without manipulation to the hi-end amplifier's DAC.
When I stream music with my macbook pro to the Apple TV with Airplay, I notice that the macbook pro internal DAC isn't bypassed causing bad sound output. I also notice that because every audio control in the macbook is still active, so you can set the voume output and use the equalizer. This means that there is a Digital to Analog conversion (for sound control) and then an Analog to Digital conversion (for the Airplay streaming) made by macbook pro internal DAC.
As I said before, this workflow causes bad sound output, so is there a way to configure Airplay to stream untouched music files bypassing the internal device DAC (the DACs of iphones, ipads and macs)?

Answer 1

Max_Ram wrote:
Are there any hi-end devices out there able to manage a shared iTunes library (like the ATV 3 does) with bit perfect output?
And has the Airplay feature in some "audiophile grade" devices like NAD, Marantz, etc. the same behaviour?
I suspect you'll find many of the high-end audio devices use custom library software - they may not run with iTunes directly, but I suspect some will be able to access files stored in iTunes.  The problem really is the AppleTV is not configurable to simply output what it is sent - I don't honestly know if for example iTunes downsamples hi def files before sending to AppleTV or if AppleTV does it internally.
In many ways it may not matter if AppleTV is not outputting as you want.
I think the problem with Airplay is that the technology is licensed from Apple for inclusion in those devices - from memory things like the first Zeppelin Air used to boast high-quality DACs but actually the Airplay stream that went to those devices was lower quality.  I've not really tested any of these things for a while to be honest and am rather out of touch with current AV gear.  Thinking about it I can use my Pioneer as an Airplay destination, but as you have noticed volume control/equaliser etc are active so the stream is not the original - must check on sample rate/bit depth though.
Airplay may or may not be capable of what you want now, but even if it isn't it may evolve to do so in the future. I suspect your best option will be to connect your Mac directly to the DAC if streaming won't work.
This is old and mentions some variably priced playback apps aimed at audiophiles:
http://www.headfonia.com/os-x-audio-players-amarra-audirvana-pure-music-fidelia- decibel-and-bitperfect/
BitPerfect is available in the AppStore - OS X removed some APIs for low level access to audio output some times ago - not sure if they are available again now.
Fidelia also in AppStore but has some in-app purchases.
Audirvana looked promising.
Not used any of these recently.
Amarra used to be very expensive.
In the past there have been several lively discussions here where people have moaned that AppleTV does not have a volume control - I have always argued that it is a 'source' device and volume etc should be controlled on the amp or TV as with conventional audio sources but many devices do have volume controls these days so consumers who like those features want them. They did actually add volume control to AppleTV 1 for stereo audio but you could disable it in Settings.