DSD limitation in Mac OS X's Core Audio?

I have been reading about the fact that, following the deprecation, by Apple, of ASIO in OS X (a few versions ago), Core Audio does not really contemplate native DSD and must resort to DoP instead.

But it seems like the downside of this is additional overhead that would require double the bit rate “bandwidth” (or whatever term), i.e. so that a DSD256 DAC would end up receiving only DSD128 from the Mac.

Could anyone elaborate further on this limitation and what exactly happens these days under the latest OS X versions? For instance, my DAC/Amp supports up to quad-DSD (11.2, DSD256) - does the fact that I use a Mac mini as core limits this somehow, or does OS X support up to DSD256 as well?


If your DAC supports a PCM rate capable of carrying the DSD DOP it will work. It’s the hardware that allows it, it’s just PCM to macOS.

So for DSD 256 to work DOP your DAC must be PCM 768 capable.

Well, that’s the issue - see the screenshot from the Technics manual:

This depends on which DAC you use.

DSD256 works on Mac OS if and only if your DAC supports DSD256 DoP. Many DSD256 DAC do not support DSD256 via DoP, but some do (e.g. Chord).

Well, I am pretty it does, even under DoP:

My question is whether the Mac mini will be the bottleneck here, given the higher overhead required for DoP under CoreAudio.

Unfortunately, this specification does not tell you what the maximum DoP rate it supports.

Likely not a problem. Whether your DAC supports DSD256 DoP is a much bigger problem.

DrTone is on the right track that usually a DAC that supports PCM 705.6kHz will probably support DSD256 via DoP (but there are exceptions, and the reverse is not necessarily true).

This information was already provided above - DSD256 is supported on the Technics SU-G30 (see screenshot showing the 11.2 support) - my comment about CoreAudio stems from this, for instance:


That screenshot actually tells you nothing. DSD256 support only means it works on Windows, it does not imply DSD256 DoP is supported.

This page states that DSD256 is Windows only:

  • DSF(.dsf) : 2.8/5.6/11.2MHz, 22.4MHz(Windows OS, ASIO Native mode only)

The other page you linked to for another DAC merely tries to avoid stating that they do not support DSD256 DoP.

That page has nothing to do with hardware DSD support - it’s only about the general reference to supported formats under the TAP software; so much so that the SU-G30 does not support DSD 22.4 at all. And no, I do not use the TAP software in any case.

It is a case of confusingly written tables. The DSD line in the first table is NATIVE only. It doesn’t say it but it is. Mac does not do native DSD, they have to rely on DoP. DoP is based on the PCM rate limit, in which case it is 384 (from that same table), so can only carry DSD128 via DoP. That is it.

The second table is just stating the USB-B can carry either signal.

So how does the Technics play DSD256 and say so on the display?