[LAU] linking soundcards

[Clemens Ladisch]

Atte André Jensen wrote:
> 1) Can I link the onboard soundcard and an usb soundcard so that they 
> appear to the system as one four channel device?

As other have already written, the clocks of different sound cards will
not run at exactly the same rate in the general case.

However, USB audio devices that use 'adaptive' output endpoints derive
their clock from the USB clock, so it is possible to use multiple USB
devices at the same frequency without their clocks drifting apart.
(The UA-1A, like most other USB audio devices, does use adaptive output
endpoints.)

This still doesn't guaranteee sample-accurate synchronisation because
it's possible that one device is started one frame (1 ms) later than the
other.


Regards,
Clemens