Thanks, Nigel.
I've just set my 16A up on Windows 10 again, and I found I needed to reinstall the current version of the driver in order for it to be visible as an ASIO device at all. (I already the current version installed, but perhaps some recent Windows 10 update had corrupted it somehow.) Also, the MOTU Discovery application doesn't find my 16A (even after reinstalling the driver and many reboots), but the 'MOTU Pro Audio WebUI Setup' application does, and it is visible as an ASIO device.
I also applied the latest firmware update to it.
Having done those things, I can confirm that:
1. It does definitely work for me as I described, i.e. you will get an error message when first changing the sample rate, but it will then work properly (if starting the audio driver via '
Engine | Advanced ... | Start audio/MIDI', and/or by using any organs of the newly-set sample rate). Hence the issue only occurs once each time that the unit actually changes sample rate (but not if the sample rate is already set correctly).
2. The fundamental issue appears to be a bug in the driver in that the driver always returns 0 Hz in response to the standard ASIOGetSampleRate function until the driver has been completely restarted. (Even if, as a test, I make Hauptwerk wait a few seconds and then re-try the query it still returns 0 Hz without completely restarting the driver.) Hence it doesn't appear to be something for which we could readily implement a work-around in Hauptwerk. I will try raising it with MOTU's support in the hopes that they might fix the driver's implementation of ASIOGetSampleRate for a future version of the driver. I will also raise with them that the MOTU Discovery application is no longer reporting the device as being present on my Windows 10 installation (even though the device is working anyway).
However, (as in 1) it does definitely work for me as I described, i.e. it's just a spurious error message when actually changing sample rates, that's easily worked around, and which doesn't occur if the sample rate is already set.
If that definitely, definitely isn't happening for you, then I can only suggest:
- Try re-installing the driver current version of the MOTU AVB Pro Audio Installer (
http://motu.com/download ), then shutting the computer and devices down fully, then starting everything up again.
- Before launching Hauptwerk (for good measure), make sure the MOTU's clock source is set to 'Internal' in the 'MOTU Pro Audio WebUI Setup' application.
- If that still doesn't solve it even when the sample rate is already correct, and unless anybody else has any suggestions, I can only suggest contacting MOTU for support, I'm afraid.
(I don't have a MOTU 24Ao myself, but as far as I know the 16A uses the same driver, so I wouldn't expect any difference in behaviour, and quite a few other Hauptwerk users use the 24Ao successfully.)
Best regards, Martin.
Hauptwerk software designer/developer, Milan Digital Audio.