[alex@burken ~]$ cat /proc/asound/card1/stream0
Sound Devices USBPre2 at usb-0000:00:02.1-2, high speed : USB Audio

Playback:
  Status: Stop
  Interface 1
    Altset 1
    Format: S16_LE
    Channels: 2
    Endpoint: 6 OUT (ASYNC)
    Rates: 8000, 16000, 24000, 32000, 44100, 48000
    Data packet interval: 1000 us
  Interface 1
    Altset 2
    Format: S24_3LE
    Channels: 2
    Endpoint: 6 OUT (ASYNC)
    Rates: 8000, 16000, 24000, 32000, 44100, 48000
    Data packet interval: 1000 us

Capture:
  Status: Stop
  Interface 2
    Altset 1
    Format: S16_LE
    Channels: 2
    Endpoint: 5 IN (ASYNC)
    Rates: 8000, 16000, 24000, 32000, 44100, 48000
    Data packet interval: 1000 us
  Interface 2
    Altset 2
    Format: S24_3LE
    Channels: 2
    Endpoint: 5 IN (ASYNC)
    Rates: 8000, 16000, 24000, 32000, 44100, 48000
    Data packet interval: 1000 us