Article: This Just In: Microsoft Launches Native Class 2 USB Audio Support. Wait, What?

[mansr]

Just now, HeadStrong said:

Does this mean there will be an update to the AQ Dragonfly to enable resolutions over 24/96???

No, that's a limitation of its microcontroller.

[mansr]

6 minutes ago, JackoUK said:

It seemed to me that WASAPI and ASIO are interchangeable in the audio stack

WASAPI and ASIO are two different interfaces for audio applications to interact with the driver. UAC2 is a specification for the USB protocol between driver and hardware. A driver can provide either or both of these regardless of the hardware protocol (UAC2 or something else). Vendor specific drivers typically implement both WASAPI and ASIO for maximum application compatibility. The new UAC2 driver from Microsoft only implements WASAPI. It probably does this because a) WASAPI is the Microsoft way (for now), and b) ASIO may require paying royalties to Steinberg.

[mansr]

23 minutes ago, JackoUK said:

... I'm sticking to my story!

"A driver can provide either or both of these [WASAPI, ASIO] regardless of the hardware protocol (UAC2 or something else)."

No, that 's the wrong way round. WASAPI and ASIO use the USB class 2 interface, implemented in the driver. The USB class 2 driver does not implement WASAPI or ASIO and indeed does not care what middleware calls it. Moreover the raison d'etre of an INTERFACE in software design is to ensure the caller and the called become independent.

UAC2 is a link protocol or, if you will, a hardware interface. While most new DACs use this standard, there are many older ones that do not, and even those that do often include vendor-specific extensions. The software interface between the driver and the rest of the OS is not standardised. Windows drivers implement whatever interface the WASAPI core requires. The ASIO core uses other/additional interfaces to the driver. This is why ASIO4ALL was created. It provides the low-level interface used by ASIO on top of standard Windows drivers.

23 minutes ago, JackoUK said:

"Vendor specific drivers typically implement both WASAPI and ASIO ..."

I think not, I think vendors do 2 things:

- they implement the USB class 2 interface on their device

- and because MSFT didn't have one, provided a USB class 2 driver for Windows

They do that, among other things. If the hardware interface isn't UAC2, they'll obviously provide a driver for whatever it is.

 

As a concrete example, I have a Tascam UH-7000 DAC/ADC. It does not use UAC2 (although it is something very similar). After installing the vendor driver, it appears under both WASAPI and ASIO, but only ASIO gives full functionality. In fact, WASAPI barely works at all.

[mansr]

19 minutes ago, JackoUK said:

"Windows drivers implement whatever interface the WASAPI core requires."

I stand to be corrected but that's where I think you are mistaken.

When MSFT claim to have a USB class 2 audio driver they are making a substantial claim. As I said USB and USB audio class 2 are industry standards not controlled by MSFT. Whether MSFT's claim is justified does of course deserve testing. have they implemented all of the standard, or as you claim only the WASAPI part of it.

USB Audio Class 2 is a hardware interface spec. WASAPI has nothing to do with it. A Windows audio low-level driver translates calls from whatever software interface WASAPI uses to suitable hardware commands. Nobody has questioned that the new Microsoft driver does exactly this for UAC2 devices. ASIO uses a different interface which this driver doesn't implement. That in no way means the driver is incomplete in terms of the UAC2 spec.

33 minutes ago, JackoUK said:

That requires a test by someone who knows the class driver specification in great detail!!

There is no such thing as a class driver specification. The spec is for hardware only. The software driver can provide whatever interface it pleases. Windows drivers provide the WASAPI low-level interface. Linux drivers provide the ALSA internal interface. Neither is covered by any standard.

37 minutes ago, JackoUK said:

Further I think ASIO would work over the MSFT driver

Chris says it doesn't, and I'm inclined to take his word for it. It probably works with ASIO4ALL though.

[mansr]

I just installed the update on my Win10 machine. UAC2 devices work just fine through WASAPI. They do not show up in ASIO applications (checked with Cubase). The onboard Intel audio does, along with aforementioned Tascam device.

[mansr]

12 minutes ago, The Computer Audiophile said:

Your DACs use custom drivers that will not be uninstalled.

I don't know about DACs, but the update replaced my Synaptics touchpad driver with an older version (that doesn't support multi-touch). The "anniversary" update did the same thing. Annoying but fixable.

[mansr]

1 hour ago, JackoUK said:

"There is no such thing as a class driver specification."

Sorry mansr but you are manifestly wrong on this crucial point: please see ...

http://www.usb.org/developers/docs/devclass_docs/

Note just one title from this International Standards body:

"APPROVED CLASS SPECIFICATION DOCUMENTS"

That's all about hardware, the thing you connect to a USB port. Drivers are software.

[mansr]

5 hours ago, scan80269 said:

This Microsoft UAC2 driver is not as "universal" as I was led to believe.  So far, two of my DACs don't work with this driver:

 

* Schiit Yggdrasil - I have a post about this

 

* Anedio D2 - No yellow bang in Device Manager so driver loaded OK, but both Foobar2000 and HQPlayer choked up trying to play any track in WASAPI mode.

 

For both these DACs, the manufacturer supplied Windows driver represents the only working driver option.

Add Steinberg UR242 to that list. The device is displayed in the control panel and applications, but it doesn't work at all.

[mansr]

1 hour ago, KDinsmore said:

Worked fine for my Wyred 4 Sound Dac2v2SE. However I started getting clicking sounds from my ripped SACD's? I've read about that before but never experienced it. Switched back to ASIO and it plays fine again. Anyone have an answer?

What format are you playing your SACD rips in?