Native Instruments, whose hardware was some of the first to prompt reader compatibility reports, now has issued a statement. I had hoped for more background on what’s actually going on – we’ll keep pressing vendors to tell us more – but the short-term advice on the MacBook Pro and Air and their USB3-only ports is clear. You’re going to want to wait until hardware you use is confirmed to work, and it seems that at least this vendor is communicating with Apple directly. (Those fixes will hopefully benefit the handful of readers we have suffering from USB3 woes on Windows, though the PCs more often have a dedicated USB2 port, not just USB3.)

Clarification: I’ve written about this before, but some readers are perhaps not hearing it. Reported compatibility issues impact hardware from multiple vendors, not just NI. It’s unclear why some drivers and devices are having issues when others are not. Until there’s a causal explanation, though, it’s difficult to point at any vendor – NI or Apple included – and place blame. I would like to see someone release more technical details on the cause, however, as I think that leaves users in a position of uncertainty, particularly when USB’s backers originally claimed USB3 would be backwards compatible.

Excerpt from today’s announcement, on Friday the 20th:

Native Instruments has conducted compatibility tests with its hardware products connected to USB 3.0 ports of current-generation MacBook Pro and MacBook Air models. Some NI products are experiencing a degraded audio signal caused by USB 3.0 audio driver issues present in recent versions of OS X.

The following products have shown to be affected:

AUDIO 2 DJ / AUDIO 4 DJ / AUDIO 8 DJ
AUDIO KONTROL 1
GUITAR RIG MOBILE
GUITAR RIG SESSION
KORE 1
RIG KONTROL 2 / RIG KONTROL 3
TRAKTOR AUDIO 2
TRAKTOR KONTROL S4

The following products have shown to be fully compatible:

KOMPLETE AUDIO 6
MASCHINE / MASCHINE MIKRO
TRAKTOR AUDIO 6 / TRAKTOR AUDIO 10
TRAKTOR KONTROL S2

NI hardware products without audio interface functionality (KORE 2, TRAKTOR KONTROL F1, TRAKTOR KONTROL X1) have also shown to be fully compatible with the current MacBook Air and MacBook Pro generation.

Native Instruments is currently in contact with Apple in order to find a solution.

http://www.native-instruments.com/en/support/online-help/compatibility/mac-os-x-compatibility/

(Emphasis mine.)

The good news is, some hardware is perfectly compatible – something we’ve heard from some other vendors (including MOTU). The bad news is, everyone else will have to wait – and notice the mention of “drivers.”

Previously (and worth looking through comments):
USB 3.0: Backwards Compatible in Theory, But Some Audio Drivers Aren’t Cooperating