macOS 10.13.2 USB audio issue

I have the same issue. I have a touch bar MacBook Pro and have the issue when connected to an old Apple Thunderbolt display or when connected to a new LG 5k Thunderbolt 3 display. So far the only workaround is to plug the DAC into an Apple USB-C to USB adapter, and plug the adapter directly into my computer. I've contacted AudioQuest support, and they weren't able to help.

I'm having the exact same issue (MacBook Pro 2015, DragonFly Black, Thunderbolt Display). It's still not working with 10.13.3. The only workaround is directly connecting the DAC to the MacBook or downgrading to 10.13.1 (not recommended).

My guess is it won't be possible to plug in a Dragonfly directly into a Thunderbolt display. It's most likely a firmware issue with either the Dragonfly's firmware or the Thunderbolt's firmware. I'm not even sure a Thunderbolt display could ever support a DAC. I don't think it's a High Sierra issue seeing the Dragonfly works perfectly well plugged directly into a Mac.

Dragonfly can be plugged directly to a thunderbolt display. I have done that for years without problems. The problem for me started with one of the MacOS updates late 2017, I dont remember which one.

Have anyone tried to connect a powered usb hub to the thunderbolt display and connect the dragonfly to the usb hub? that was a tip I got from audioquest support.

I have an LG 5k display, which is a Thunderbolt 3 display. Using a powered hub made no difference. With 10.13.2, I had interference at any frequency. With 10.13.3, switching to 48,000 Hz seems to make the problem go away.

The funny thing now, is that the Dragonfly Red DAC connected to my thunderbolt display works almost without any distortion issues. I have experienced distortion for a couple of seconds once during the last 20 minutes. I have two thunderbolt displays with firmware version: 26,2.

Before the DAC started working better, I unplugged the USB DAC, did a few facetime calls, both video and audio calls and used the display speakers, moved facetime video call from screen B to screen A.. Midi settings is at 48 000 Hz.

This issue is driving me nuts. Its like looking for a needle in a haystack.

Could it be some static electricity buildup which got unloaded by using the thunderbolt display camera and speakers?

Partly fixed. Works fine with midi setting set to 48 000 Hz, but problem shows up again at 96 000 Hz.. I had problem with all of the different Hz before the update. Finally it is possible to listen to music with my dragonfly connected to the thunderbolt display

This never ends... After listening for a while now at 48000 Hz, suddenly I have started experiencing heavy stuttering instead of distortion. I could at least listen for a while without issues.

I have tested all of the Dragonfly versions earlier, same problem. I even have JitterBug and DragonTail, same problem with distortion.

Apple are obviously working on fixing it, so we just have to wait......

When the stuttering happens, I get a massive amount of these errors in the console

coreaudiod HALS_IOA1Engine.cpp:365:EndWriting: HALS_IOA1Engine::EndWriting: got an error from the kernel trap, Error: 0xE00002EE

As of the full release of 10.13.4, my Audioquest DragonFly Red is fully working again. Yay!

I have a cheapo USB DAC, and have not had any problems with it. Have you tried other audio formats? It seems happier at 48,000 Hz than the recommended 44,100 Hz for me.