Comment 6 for bug 785939

No problem :) I'm happy to help in whatever way I can.

Here's the output of "aplay -l" when the mixer is connected:

**** List of PLAYBACK Hardware Devices ****
card 0: PCH [HDA Intel PCH], device 0: ALC269VB Analog [ALC269VB Analog]
  Subdevices: 1/1
  Subdevice #0: subdevice #0
card 0: PCH [HDA Intel PCH], device 3: HDMI 0 [HDMI 0]
  Subdevices: 1/1
  Subdevice #0: subdevice #0
card 1: TTM57SL [TTM57SL], device 0: USB Audio [USB Audio]
  Subdevices: 0/1
  Subdevice #0: subdevice #0
card 1: TTM57SL [TTM57SL], device 1: USB Audio [USB Audio #1]
  Subdevices: 1/1
  Subdevice #0: subdevice #0

I should mention that I'm able to get some functionality with this mixer and xwax/Mixxx. The problem is that I have to set the mixer to output the control tone, so that xwax/Mixxx can pick up the signal. Unfortunately, this means that the control tone is affected by the crossfader, so it cuts out and prevents vinyl position tracking.

When I'm using the mixer with Serato, I set the mixer to output the digital signal coming back from Serato, which carries the overlayed audio. In this set up, the control tone is unaffected by the crossfader, only the overlayed audio is (which is what we want to happen with xwax/Mixxx).

Is this simply a case of mimicking the initial USB communication between Serato and the TTM57SL, within Mixxx, or is this something for the ALSA development team?