New DAC has distorted/clipped audio w/new Mac and OS 10.10

[fullheadofnothing]

The "upstairs" Mac will go to the latest version. Want me to try to break it, Doc?

[Doc B.]

Arghh. OK, let 'er rip.

[fullheadofnothing]

Alright, after the many hour long joy of installing an OS, I have results.

The DAC runs on an early 2009 MacMini running OSX 10.10.2.

In other words, the DAC is fully compatible with:

    USB 3 running on 10.9

AND

    USB 2 running on 10.10

Testing has been done with iTunes and Audirvana under 10.9 and VLC and Amarra under 10.10.

[aroide]

Thanks everyone for looking into this and checking all these options out.  I did find several issues with OS X 10.10 and USB DACs with USB3 ports when doing a google search.  In one case I found, the same behavior was seen.  Here is the text from an audiogon post:

Hi, folks. I "upgraded" my MacAir to OSX Yosemite on Tuesday and now my DAC (Esoteric K-03) won't work properly. Whether on iTunes, Amarra or Audirvana, I get about 15 seconds in before the sound begins to warble, distort, chatter and finally stop altogether. I'm assuming it's a driver issue (there hasn't been an updated Mac driver on Esoteric's website since 2011), but I'm wondering if anyone else has had this problem and if there are any creative fixes anyone has discovered. Thanks!

So at this point, its probably good to send the DAC back to me.  I now know it wasn't a firmware, loose connector, etc issue.  My solution for now will be to put a USB2 hub in the signal path.  This has worked around many of the issues seen on the web.  I may get some additional jitter, but as both devices will be async and able to pump data music faster than is ever needed, probably not an issue.

Thanks again for looking into this.  I will update the forum on my workaround, and will periodically check operation with the usb2 hub removed to see if some 10.10 update fixes the incompatibility.

As a side bonus, your upstairs mac is not on 10.10 



Tony

[Doc B.]

OK, will do. I will try a DAC with my son's new Macbook Air when I see him next, and will certainly report if I can reproduce the problem and if we find any clues to a remedy.

[fullheadofnothing]

Had I been able to create the failure mode, my first plan to resolve it was to try setting up a firmware password:

http://apple.stackexchange.com/questions/97157/preventing-booting-from-external-media

The reason behind my thinking here is that the problem on Windows 8 has been related to the USB boot option in the BIOS, so the closest I could find to disabling that on a Mac was this. No idea if it will work or not, but if dropping the USB3  to USB 2 via a hub doesn't work, it might be something to try.

I just slapped a label on your box, so you should see it in a few days. Please update the thread if you figure anything out.

[dw]

I found the same problem as decribed in this thread when I tried a mac pro cyclinder with usb 3.0 ports.
I used AudioGate as the player. A few seconds after AudioGate plyas a song, the DAC disappears from the list of devices seen
in the audio/midi window. I don't recall any sound coming from the DAC. Rebooting the DAC brings it back as a device.
I have not tried any workarounds. I'm running OSX 10.10.2.

-Dave

[aroide]

Here is something to try (when my dac arrives I will try this).  Several people have reported issues when vt-d is enabled.  Here is something I found on disabling vt-d and seeing what happens:

The fix is to disable VT-d by entering the following command in Terminal, then restarting the Mac:

sudo nvram boot-args="dart=0x0"

This change is reversible by deleting the boot-args parameter in nvram, which you can do by entering the following command, then restarting:

sudo nvram -d boot-args

Comment added by Joshua Harris:
Caveat emptor, this solution could cause issues if your startup drive is an SSD. Please research carefully before applying this method to a computer with an SSD.

[rburrows]

I'm experiencing similar issues with a 2014 Macbook Pro Retina with USB 3 ports. Toslink output from the computer is fine, but with USB:

• with Midi Settings at 44.1 khz, 24-bit, the DAC plays garbled music for a few seconds then becomes unrecognized by the computer, requiring a DAC restart.
• with same Midi Settings but using Aroide's system tweak above, the DAC plays for about 30 seconds, still garbled but less so, before the DAC becomes unrecognized. Resetting the tweak restores the original behavior.
• on an older Macbook Pro from 2009 it plays with no problems

[fullheadofnothing]

There are 8 models of 2014 MacBook Pros with Retina. Can you be more specific? Also what player? What OS?

••••••••••

Has anyone tried the USB 2 hub trick yet? Does it work?

Has anyone tried the firmware password?

Are any of you still covered under AppleCare on these machines? Has anyone placed a call in?

[rburrows]

More specifically, my device is:

MacBook Pro (Retina, 15-inch, Mid 2014)
https://support.apple.com/kb/SP704?viewlocale=en_US&locale=en_US

running OS X Yosemite 10.10.2 (14C109)

Players are Plex, iTunes, Spotify (same as on the 2009 machine)

[fullheadofnothing]

Several of the machines listed here are old enough that they didn't come with 10.10 installed. It looks like it's pretty simple to roll back if you have TimeMachine backups from before your "upgrade." Anyone care to try?

[dw]

I don't want to volunteer my machine for the roll back as its really my day-to-day work machine. I have an older mac pro with usb 2.0
that works fine with the dac and that machine has the audio duties.

I did some searching on the internet a while back and there are a lot of reports of dacs having trouble with usb 3.0. This is across various platforms,
not just recent macs. The most common workaround is the usb 2.0 hub. I haven't searched enough to find a dac manufacturer that "fixed" the
usb 3.0 issues. I believe I have seen reports of some dacs working on usb 3.0 while others did not for the same platform. At some point I could try my
4+ year old emu dac with the modern usb 3.0 mac pro I have.

I don't know if the fault lies in the host or the dac. I'm wondering if the dac has disconnected from the host has the dac "crashed". If it has, is there a way to
use a logic analyzer or some other hardware device to see where it crashed or what led up to the disconnect? I'm sure John does this all the time in his
development.

I don't think this is too serious as long as the usb 2.0 hub workaround works. I love the dac and am very happy with the sound.

-Dave

[fullheadofnothing]

There are several options for fixing this. You have chosen one (using a different machine). That works for you, so great. It's the people who don't have that option that we are trying to find solutions for. So far, one solution seems to have not worked, and no other ones have been tried.

We know that it's the combination of 10.10 AND USB 3.0 that causes the issue*. That's why I'm suggesting rolling back for those that can with relative ease. Searching online shows that it is not just our hardware, but other hardware as well. The U in USB is universal; there is a hardware/OS implementation that removes the universality. This is a problem that Apple needs to fix. Do they know they need to fix it? That's why I'm encouraging people to contact Apple if they are still qualifying for the free phone support for a recent purchase; it gets the problem logged in their system.



*The USB 3.0 issues we have encountered on the Windows side have been limited to Windows8, and resolvable with a change in BIOS settings.

[aroide]

I received my DAC back and have been trying some things out:

- OSX 10.10.3 upgrade did not change behavior
- VT-d fix does not work (same behavior).
- USB2 hub does not work (same behavior).

This might be an XMOS firmware issue or a combo of a firmware behavior and new USB3 chipset/driver.  My other DAC has an XMOS front-end and works fantastic with same exact mac and SW to its max of 384Khz.  It probably will take a debug version of XMOS firmware and a USB3 protocol analyzer to figure this one out.

I'm going to have to either resurrect a VERY old mac mini (the first one ever) or switch to toslink until something is figured out.  But that limits some of my 24/192 source.  Crap.

Does XMOS provide a OS X driver?  Everyone says one isn't needed, but maybe adding their driver fixes the issue.  I believe that only licensed developers can get access to those kinds of things.