USB audio configuration on MAC creates distortion

Dear all,
After noticing several problems with my DAC (TotalDac D1 Direct) connected via USB to my MAC running Audirvana, I made a few checks and discovered:

  • The issue exists with other players,
  • The issue may be due to an USB audio driver (Xmos USB Audio 2.0) I installed before.

So my questions:

  • How to remove that old driver and get back to the good old Apple USB Audio for OSX Sierra?
  • What is the most appropriate Audio configuration: I used 44.1K 24bits before, then I switched to 96K?

Have you tried from the applications? Is the driver package visible there? If yes, just drag it to trash.

You can also start the driver installer again. Sometimes there is a un-installer there that you can execute.

I am also connecting my Mac mini to my DAC via USB and was reading comments in this forum about the “direct mode” feature very appreciated by Audirvana users because it would bypass the Mac core audio software.

You have a very high end DAC supporting Upnp/DLNA protocols.
You might get better audio results by not using the Mac - core audio - USB signal path …

Have you considered connecting Audirvana to your Totaldac via your local network, using DLNA ?
It might be worth trying this configuration, you may end up with a better sound, and avoid this USB driver bug.

my suggestion above makes sense only if your Totaldac Direct has the streamer option , I think the “basic Totaldac Direct” do not support these protocols.
I think this option can be installed as un upgrade anyway , but the price must be significant …

With your DAC, being R2R, you’ll probably get the best results from redbook 16/44.1 files.

@patifr what OS are you using? what you are describing is the main reason i will never upgrade from el capitan
also could be your USB ports not being able to handle the power—Schiit Audio suggests using a powered ‘hub’ for you USB input-- go to their web page and read about this
also there are several threads throughout Audiophile Style (AS) formally computer audiophile(CA) about your problem

Bonjour Alain,
You are right, that could be an option but my DAC does not have the streamer option as you perfectly catch. I tried that UpNp through a Marantz NA11-S1 but the sound was significantly worse than with a direct USB connection.
I’m now considering to buy either the streamer option or to buy a separate TotalDac streamer which is quite an expensive piece but this is the price of high quality devices I guess.

Hi bitracer,
You could be right but in the list of available options in the driver configuration:

  • I cannot change the bit depth (Only 24 bits)
  • I previously used 44.1 setup but problems are appearing in that configuration

I started to make a try using 96K configuration and so far so good, but this does not mean anything. In addition, since I changed the default driver configuration I have the impression the sound is not as good as it was but it could ne me…

Hi bobmd,
I’m using Sierra and I should probably have kept El Capitan!
Considering the lack of power of the USB port, that could be a source of problems as I noticed on another MacBook trying to use an external USB drive. But adding external power source to my setup would probably add sources of noises and problems.

Hi bitracer,

Thanks for the advice. Unfortenately, the driver came from a package (.pkg) I got on some websites. There is no real application behind. Maybe in the package I could find something but I don’t know how to look inside. Any idea?

You can try to remove manually.

Look at the folders below and remove references to USB Audio (USB Audio ASIO whatever):
/Library/Application Support

Look also in the same folders under your home directory:
~/Library/Application Support

Also now that Catalina is out, you might want to consider doing a clean install.

I’ll have a look at it but in the meantime I managed to gather some more facts:
1/ The USB Audio driver I thought I was using (the cause of some troubles) is maybe not the culprit.
2/ I checked its name in the installation package and got “async192.kext”. I checked and that kext is loaded.
3/ But, and this is where the whole thing comes to be quite interesting: if connect to my MAC the USB I/F from my CD player (the one for which I used that driver/Kext), then I got an immediate reboot of the MAC.
4/ So, I came to the conclusion that this async192 kext is not compatible with the Sierra version, although still loaded at boot time.
5/ Difficult to find out what caused the boot to occur: navigating into those log files is a nightmare…
6/ Still looking for the Xmos driver that apparently my MAC uses each time I connect the DAC but nothing found at this stage.
7/ Do not understand how the link is made at system level to the right driver/kext when an external audio device is plugged in.

Still looking at it. And considering to look on the streamer side to replace (partially/totally the MAC).

I would look into the built-in solution for your DAC. Baying a streamer and still using USB to the DAC doesn’t make much sense. It’s better than USB from a computer directly, but still.

USB is generally crappy interface for audio.

I wonder why you felt the need to install the special drivers you installed. Macs support USB Class 1 and Class 2 audio devices out of the box.

Which driver will be used it determined by the USB device id. Anyway, at this point you’re better of by just reinstalling the OS, unless you find pleasure digging deeper and resolving the issue.

Thanks bitracer. When mentionning the streamer option I had in mind to replace the USB I/F with the UpNp protocol via the network. I don’t know if this would be better (in terms of sound quality) but is certainly worth a try.
Regarding the issue itself, although I find interesting to dig into the issue, I would prefer to use my time differently, so I guess I will look for a different solution. Anyway, my Mac is pretty old (8 years) and would deserves a refresh.

If your running a desktop pc, I tried buying a $50 7-port 3.2 expansion card, and after plugging my dac directly into that, instead of directly into the motherboard’s usb port, my audio got way more spacious, and more proper sounding. This was instead of trying one of the >$300 dedicated audiophile single usb port expansion cards, and was still worth it for sq, with 6 extra 3.2 ports to use, too.

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AES is the best input for TotalDac. So what about a good USB to AES converter? Maybe Vincent can recommend one to you?


To use with Audirvāna I am assuming? I wouldn’t purchase any hardware that cannot be returned after a fair testing period. You have probably already read enough about UPNP implementation and Audirvāna to understand sometimes it can be a challenge.

What @matt recommends sounds like a most likely successful solution.

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Hi @matt @OffRode
Thanks for your advices but the initial post is a bit old and in the meantime I found a complete solution using a streamer from TotalDac and an AES/EBU link to the DAC.
Just like what you @matt recommended!
And it works like a charm! Some minor problems with specific audio formats and a new version of the SW on the streamer side but quickly fixed thanks to the good support from TotalDac.
Just to complexify the setup, I also bought a MELCO server with the intention to simplify the whole solution and get rid of additional computers/servers/SW. But, I have to admit it, nothing beats the AS sound quality.
Anyway, thanks for your help and excellent advices!

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Just for my understanding:
You get the best SQ when you go from AS (laptop?) via UPnP to your TotalDac streamer and then into the AES input of your TotalDac.


Yes, that’s correct!
Actually, the source is a Mac Mini and audio files are stored on a Synology diskserver.
A complicated setup indeed…