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Mac OS X audio driver and SQ

RZangpo2

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I have a large collection of Redbook CDs (also SACDs, but that's another matter). I play them on a universal disc player, running the digital signal into a Benchmark DAC3 via Toslink or coax.

I've also tried ripping them and playing them back off the hard drive of my MacBook Pro using the VOX player, also into the DAC3, but they don't sound as good this way. That's unfortunate, as I've also purchased and dowloaded hi res PCM files over the years (mostly of classical music), and streaming them from the hard drive is the only way I'm able to play them. I know I'm not getting the best possible SQ this way.

At one point I had the Audirvana player, which had Direct Mode, bypassing the OS X Core Audio driver. Files played back off the hard drive did sound better this way, but at some point, according to Audirvana, OS X no longer supported Direct Mode.

My question is, is the inferior sound quality I'm getting from the MacBook/VOX/DAC3 chain, as compared to the universal player/DAC3 chain, due to the Mac OS X Core Audio driver? And if so, is there anything I can do to bypass it? TIA!
 
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kongwee

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I did it with iTune in the past. I use AIF. It has DRM. Only admin/user account can access AIF, unfortunately.
 
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RZangpo2

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If the DAC is recognized by MacOS it should be able to receive hires streams via USB. A utility like SoundSource may be helpful to manage sound output on the Mac.
Yes, the DAC receives hi res streams via USB. Are you saying I could use SoundSource to bypass Core Audio? And this is something VOX can't do?

LATER. Looked at the SoundSource web page. It doesn't bypass Core Audio, it simply manages the system audio settings. Doubt it would sound better than VOX, which does have Hog Mode (exclusive access), though not Direct Mode.
 
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RZangpo2

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Just use roon
Does Roon bypass the Core Audio driver? I looked at their page but didn't see anything about that.

Thanks for the recommendations, but I'm not looking for another streaming app. I'm looking for the answer to the following question, from my original post:

My question is, is the inferior sound quality I'm getting from the MacBook/VOX/DAC3 chain, as compared to the universal player/DAC3 chain, due to the Mac OS X Core Audio driver? And if so, is there anything I can do to bypass it? TIA!
 

dc655321

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I have a large collection of Redbook CDs (also SACDs, but that's another matter). I play them on a universal disc player, running the digital signal into a Benchmark DAC3 via Toslink or coax.

I've also tried ripping them and playing them back off the hard drive of my MacBook Pro using the VOX player, also into the DAC3, but they don't sound as good this way. That's unfortunate, as I've also purchased and dowloaded hi res PCM files over the years (mostly of classical music), and streaming them from the hard drive is the only way I'm able to play them. I know I'm not getting the best possible SQ this way.

At one point I had the Audirvana player, which had Direct Mode, bypassing the OS X Core Audio driver. Files played back off the hard drive did sound better this way, but at some point, according to Audirvana, OS X no longer supported Direct Mode.

My question is, is the inferior sound quality I'm getting from the MacBook/VOX/DAC3 chain, as compared to the universal player/DAC3 chain, due to the Mac OS X Core Audio driver? And if so, is there anything I can do to bypass it? TIA!

The AIFF or FLAC rip of a CD contains exactly the same data as the CD itself - bit for bit.

Have you controlled for the possibility (inevitability) that the signal into the DAC3 is at different levels between the Macbook and CD player?
You must ensure that the electrical signals into the DAC3 are the same in order to attempt to discern differences.
Any small difference in loudness will skew preference to the louder sample...
 

Marc v E

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I used audirvana years ago, with direct mode and playing from menory not the hard disk. Ime it was not a pleasant experience; I would recommend using a real streamer based on the raspberry pi. It would be nice if you could start playing from usb stick as that is the least expensive and technically easiest way to start if you don't want to spend a lot on a Nas.


Then add a Nas if you really like it and want to add a big music library.
 
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FooYatChong

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Core Audio is the audio layer of OS X so you can't bypass it.
What you can bypass is the system mixer which down/upsamples everything to the samplerate set in audio/MIDI Config.
Vox (like most players) has a setting for that called Exclusive Access. This allows the player to send audio in the original samplerate to your dac.


vox-audio-basic.png
 

Zek

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In Audirvana - Exclusive Access

Screenshot 2022-07-02 at 19.44.22.png
 
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RZangpo2

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Core Audio is the audio layer of OS X so you can't bypass it.
What you can bypass is the system mixer which down/upsamples everything to the samplerate set in audio/MIDI Config.
Vox (like most players) has a setting for that called Exclusive Access. This allows the player to send audio in the original samplerate to your dac.


View attachment 216094
Thank you, yes, I use Exclusive Access (Hog Mode) just as you show but it doesn't solve the problem. So there's no way to bypass Core Audio, then? If that's the source of the problem, then it seems like there's no solution but to continue using the transport->DAC chain, as opposed to the hard drive->VOX->DAC chain.
 

Marc v E

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Thank you, yes, I use Exclusive Access (Hog Mode) just as you show but it doesn't solve the problem. So there's no way to bypass Core Audio, then? If that's the source of the problem, then it seems like there's no solution but to continue using the transport->DAC chain, as opposed to the hard drive->VOX->DAC chain.
There is a solution but it involves a streamer like a raspberry pi that is connected to your dac and receives data from a Nas, which is in essence a Network Attached Harddrive (storage is the official term). If you plug in a usb thumb drive or harddisk via usb the raspberry pi's playback software might automatically recognise that as well, although I'm not 100% sure, as I never did that.

Btw: playback quality this way is at least as good as the best cd transport.
 

dc655321

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Thank you, yes, I use Exclusive Access (Hog Mode) just as you show but it doesn't solve the problem. So there's no way to bypass Core Audio, then? If that's the source of the problem, then it seems like there's no solution but to continue using the transport->DAC chain, as opposed to the hard drive->VOX->DAC chain.

I don’t see where/how you’ve established that there is a actual problem here to solve.

i.e. is this another listening “test” with no controls on loudness between sources?
 

voodooless

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Hog mode should give you bit perfect audio. If its still sounds different, then the rip might not be good, or the high-res version is a different master than the one you are used to, or the most likely thing: your imagination it.
 
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RZangpo2

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Hog mode should give you bit perfect audio. If its still sounds different, then the rip might not be good, or the high-res version is a different master than the one you are used to, or the most likely thing: your imagination it.
Perhaps, but it seems more likely to me that there's a source of noise somewhere along the line. Playback via the hard drive->VOX->DAC chain is somewhat flat and grainy compared to that via the transport->DAC, which indicates noise to me.

The reason I suspect the Core Audio driver is that, based on memory, I believe Direct Mode sounded better. (Direct Mode doesn't exist anymore, so I can't do a real-time comparison.) Audirvana at one time had both Hog Mode and Direct Mode, so they must not be the same thing.

I'm playing back the same CDs, so the question of different masterings doesn't enter into it. Don't think there's anything wrong with the rips, either.
 
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voodooless

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Perhaps, but it seems more likely to me that there's a source of noise somewhere along the line. Playback via the hard drive->VOX->DAC chain is somewhat flat and grainy compared to that via the transport->DAC, which indicates noise to me.
Do you hear noise if you playback silence? If no, there is no noise problem.
The reason I suspect the Core Audio driver is that, based on memory, I believe Direct Mode sounded better. (Direct Mode doesn't exist anymore, so I can't do a real-time comparison.) Audirvana at one time had both Hog Mode and Direct Mode, so they must not be the same thing.
As I said before, Hog mode is bit perfect. The DAC dictates the data transfer rate. It gets the same bits as via your other transport.
I'm playing back the same CDs, so the question of different masterings doesn't enter into it. Don't think there's anything wrong with the rips, either.
Well, then Occam’s razor is probably right once again.
 
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I have Audirvana and Amarra Luxe. I have Neutron on my iphone. I have Plex, Fidelia, and Bitperfect too. I ran Foobar2000 in Wine. I might be forgetting some. I have not tried Roon.

Each of these has had nice features. Neutron is amazing, kinda wish it ran on Mac OS. I tried all of these because each had flaws that were aggravating, or Mac OS eventually broke something. I do still use Plex since it works so well on many systems. It sounds great but it's not bit-perfect AFAIK.

But the one I settled on is Jriver. It has an ugly duckling interface that some people hate, but I find it charming for some reason. It has exclusive access and streams locally on my local network with a decent (though minimalist) browser interface. It does a million things, many that I have not tried.

One Jriver thing I found indispensable: You can create playlists that remove duplicates (the inevitable result of ripping 100s of CDs with iTunes). I have not figured out how to do this with other software.

I can't hear the difference between these apps, with the possible exception of Amarra, which makes some recordings sound better than the others (maybe it's euphonic, and therefore not bit-perfect?).

All this said, I'm really enjoying a return to playing CDs on vintage Sony carousel players from the 1990s.
 
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sq225917

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I've compared the following at various times on the mac into different dacs via USB. Audivarna, itunes/music, bitperfect, Amarra, birdsong, puremusic, fidelia, vox, vlc, real play.

They all sound exactly the same.

One old older dac via macbook pro used to get some noise come through from the mouse polling via the usb sockets, this was groundloop noise caused be leakage of the smps in the magsafe power brick. Fixing this in the psu removed this.

Bit perfect digital sounds the same, unless something else is broken.
 

tuga

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I have a large collection of Redbook CDs (also SACDs, but that's another matter). I play them on a universal disc player, running the digital signal into a Benchmark DAC3 via Toslink or coax.

I've also tried ripping them and playing them back off the hard drive of my MacBook Pro using the VOX player, also into the DAC3, but they don't sound as good this way. That's unfortunate, as I've also purchased and dowloaded hi res PCM files over the years (mostly of classical music), and streaming them from the hard drive is the only way I'm able to play them. I know I'm not getting the best possible SQ this way.

At one point I had the Audirvana player, which had Direct Mode, bypassing the OS X Core Audio driver. Files played back off the hard drive did sound better this way, but at some point, according to Audirvana, OS X no longer supported Direct Mode.

My question is, is the inferior sound quality I'm getting from the MacBook/VOX/DAC3 chain, as compared to the universal player/DAC3 chain, due to the Mac OS X Core Audio driver? And if so, is there anything I can do to bypass it? TIA!

Nothing wrong with using MacOS for music file playback, just use a dedicated high-fidelity player (Audirvana, HQPlayer, etc.) or try BitPerfect, an iTunes/Music add-on:

 
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