Thanks for the feedback.
With single deck everything works ok.
I will try to search the archives as suggested.
19. 9. 2012 v 0:48, Mark Hills <mark@...>:
> On Mon, 17 Sep 2012, Jakub Lauda wrote:
>> as a newbie I am running in some issues trying to get xwax running on
>> MacBook Pro 8.1, with ubuntu 12.04 and stanton scratchamp first version.
>> in kern.log I get the message:
>> Sep 17 01:03:56 vitabook kernel: [ 936.552675] hub 1-1.3:1.0: USB hub found
>> Sep 17 01:03:56 vitabook kernel: [ 936.553516] hub 1-1.3:1.0: 4 ports
>> Sep 17 01:03:56 vitabook kernel: [ 936.855625] usb 1-1.3.1: new full-speed
>> USB device number 10 using ehci_hcd
>> Sep 17 01:03:57 vitabook kernel: [ 937.283140] usb 1-1.3.2: new full-speed
>> USB device number 11 using ehci_hcd
>> Sep 17 01:05:14 vitabook kernel: [ 1014.843844] cannot submit datapipe for
>> urb 0, error -28: not enough bandwidth
>> Probably some issue with the snd_usb_audio driver. But googling around
>> didn't get me any further.
> If I recall, the ScratchAmp v1 declares itself as a USB 1 device, but to
> stream 2x 44100Hz stereo audio channels requires just slightly more than
> the available bandwidth. Thus it made a small abuse of the standard in
> order to actually do the task in hand. Maybe ehci_hcd and other Linux USB
> drivers have tightened up to this.
> This feels familiar, like it has been asked before. Perhaps search the
> archives of this list, or alsa-devel.
> Does it work with only a single deck?
> It may be worth taking this to the alsa-devel mailing list. Technical
> correctness is very welcome, but then the device used to work on Linux --
> this is definitely a regression. The ScratchAmp is definitely capable of
> achieving the required bandwidth, maybe some kind of workaround is needed.
> Unfortuntely, I no longer have my ScratchAmp v1 to test.
> It would be good to see this working again. It may be an old device, but
> it works very well with the right kernel.