Alsacap gives me this
*** Scanning for playback devices ***
Card 0, ID `m2x4HD', name `miniDSP 2x4HD'
Device 0, ID `USB Audio', name `USB Audio', 1 subdevices (1 available)
2 channels, sampling rates 44100, 48000, 88200, 96000, 176400, 192000 Hz
Sample formats: S16_LE, S32_LE
Subdevice 0, name `subdevice #0'
Card 1, ID `UR824', name `Steinberg UR824'
Device 0, ID `USB Audio', name `USB Audio', 1 subdevices (1 available)
12..26 channels, sampling rates 44100, 48000, 88200, 96000, 176400, 192000 Hz
Sample formats: S24_3LE
Subdevice 0, name `subdevice #0'
Card 2, ID `Mic8k', name `ZY Control Mic8k'
Card 3, ID `CODEC', name `USB Audio CODEC'
Device 0, ID `USB Audio', name `USB Audio', 1 subdevices (1 available)
1..2 channels, sampling rates 32000, 44100, 48000 Hz
Sample formats: S8, U8, S16_LE
Subdevice 0, name `subdevice #0'
Card 4, ID `PCH', name `HDA Intel PCH'
Device 0, ID `ALC892 Analog', name `ALC892 Analog', 1 subdevices (1 available)
2 channels, sampling rates 44100, 48000, 96000, 192000 Hz
Sample formats: S16_LE, S32_LE
Subdevice 0, name `subdevice #0'
Device 1, ID `ALC892 Digital', name `ALC892 Digital', 1 subdevices (1 available)
2 channels, sampling rates 32000, 44100, 48000, 88200, 96000, 192000 Hz
Sample formats: S16_LE, S32_LE
Subdevice 0, name `subdevice #0'
Card 5, ID `NVidia', name `HDA NVidia'
Device 3, ID `HDMI 0', name `HDMI 0', 1 subdevices (1 available)
2..8 channels, sampling rates 32000, 44100, 48000, 88200, 96000, 176400, 192000 Hz
Sample formats: S16_LE, S32_LE
Subdevice 0, name `subdevice #0'
Device 7, ID `HDMI 1', name `HDMI 1', 1 subdevices (1 available)
2..8 channels, sampling rates 32000, 44100, 48000, 88200, 96000, 176400, 192000 Hz
Sample formats: S16_LE, S32_LE
Subdevice 0, name `subdevice #0'
Device 8, ID `HDMI 2', name `HDMI 2', 1 subdevices (1 available)
2 channels, sampling rates 32000, 44100, 48000 Hz
Sample formats: S16_LE, S32_LE
Subdevice 0, name `subdevice #0'
Device 9, ID `HDMI 3', name `HDMI 3', 1 subdevices (1 available)
2..8 channels, sampling rates 32000, 44100, 48000, 88200, 96000, 176400, 192000 Hz
Sample formats: S16_LE, S32_LE
Subdevice 0, name `subdevice #0'
Device 10, ID `HDMI 4', name `HDMI 4', 1 subdevices (1 available)
2..8 channels, sampling rates 32000, 44100, 48000, 88200, 96000, 176400, 192000 Hz
Sample formats: S16_LE, S32_LE
Subdevice 0, name `subdevice #0'
Device 11, ID `HDMI 5', name `HDMI 5', 1 subdevices (1 available)
2..8 channels, sampling rates 32000, 44100, 48000, 88200, 96000, 176400, 192000 Hz
Sample formats: S16_LE, S32_LE
Subdevice 0, name `subdevice #0'
Device 12, ID `HDMI 6', name `HDMI 6', 1 subdevices (1 available)
2..8 channels, sampling rates 32000, 44100, 48000, 88200, 96000, 176400, 192000 Hz
Sample formats: S16_LE, S32_LE
Subdevice 0, name `subdevice #0'
Card #1 is the relevant one.
Here's the relevant info from pulseaudio (pactl list sinks) in case that helps:
Sink #3
State: SUSPENDED
Name: alsa_output.usb-Yamaha_Corporation_Steinberg_UR824-01.multichannel-output
Description: Steinberg UR824 Multichannel
Driver: module-alsa-card.c
Sample Specification: s24le 26ch 44100Hz
Channel Map: front-left,front-right,rear-left,rear-right,front-center,lfe,side-left,side-right,aux0,aux1,aux2,aux3,aux4,aux5,aux6,aux7,aux8,aux9,aux10,aux11,aux12,aux13,aux14,aux15,aux16,aux17
Owner Module: 11
Mute: no
Volume: front-left: 16848 / 26% / -35.40 dB, front-right: 16848 / 26% / -35.40 dB, rear-left: 16848 / 26% / -35.40 dB, rear-right: 16848 / 26% / -35.40 dB, front-center: 16848 / 26% / -35.40 dB, lfe: 16848 / 26% / -35.40 dB, side-left: 16848 / 26% / -35.40 dB, side-right: 16848 / 26% / -35.40 dB, aux0: 16848 / 26% / -35.40 dB, aux1: 16848 / 26% / -35.40 dB, aux2: 16848 / 26% / -35.40 dB, aux3: 16848 / 26% / -35.40 dB, aux4: 16848 / 26% / -35.40 dB, aux5: 16848 / 26% / -35.40 dB, aux6: 16848 / 26% / -35.40 dB, aux7: 16848 / 26% / -35.40 dB, aux8: 16848 / 26% / -35.40 dB, aux9: 16848 / 26% / -35.40 dB, aux10: 16848 / 26% / -35.40 dB, aux11: 16848 / 26% / -35.40 dB, aux12: 16848 / 26% / -35.40 dB, aux13: 16848 / 26% / -35.40 dB, aux14: 16848 / 26% / -35.40 dB, aux15: 16848 / 26% / -35.40 dB, aux16: 16848 / 26% / -35.40 dB, aux17: 16848 / 26% / -35.40 dB
balance 0.00
Base Volume: 65536 / 100% / 0.00 dB
Monitor Source: alsa_output.usb-Yamaha_Corporation_Steinberg_UR824-01.multichannel-output.monitor
Latency: 0 usec, configured 0 usec
Flags: HARDWARE DECIBEL_VOLUME LATENCY
Properties:
alsa.resolution_bits = "24"
device.api = "alsa"
device.class = "sound"
alsa.class = "generic"
alsa.subclass = "generic-mix"
alsa.name = "USB Audio"
alsa.id = "USB Audio"
alsa.subdevice = "0"
alsa.subdevice_name = "subdevice #0"
alsa.device = "0"
alsa.card = "1"
alsa.card_name = "Steinberg UR824"
alsa.long_card_name = "Yamaha Corporation Steinberg UR824 at usb-0000:00:1d.0-1.7, high speed"
alsa.driver_name = "snd_usb_audio"
device.bus_path = "pci-0000:00:1d.0-usb-0:1.7:1.1"
sysfs.path = "/devices/pci0000:00/0000:00:1d.0/usb3/3-1/3-1.7/3-1.7:1.1/sound/card1"
udev.id = "usb-Yamaha_Corporation_Steinberg_UR824-01"
device.bus = "usb"
device.vendor.id = "0499"
device.vendor.name = "Yamaha Corp."
device.product.id = "1505"
device.product.name = "Steinberg UR824"
device.serial = "Yamaha_Corporation_Steinberg_UR824"
device.string = "hw:1"
device.buffering.buffer_size = "1048554"
device.buffering.fragment_size = "524238"
device.access_mode = "mmap+timer"
device.profile.name = "multichannel-output"
device.profile.description = "Multichannel"
device.description = "Steinberg UR824 Multichannel"
module-udev-detect.discovered = "1"
device.icon_name = "audio-card-usb"
Formats:
pcm
One interesting thing I noted is that pulse and alsacap seem to be seeing a different supported PCM output format (S24_LE vs. S24_3LE)? Not sure how significant that is. When I try to set MC to use S24_LE like pulse seems to do, playback just fails (no loud noise).