> The 8000, 11025, 16000 and 22050 values are capture samplerates (see below /proc/asound/card1/stream0 output), for playback the card support 32000, 44100, 48000. > > my laptop is running kernel 3.17.1 and the raspberry kernel 3.12.29, which are less than a year apart and both reports the same capabilities, so why PA 5 detects different samplerates? I even run PA as root to discard file permissions problems but the result is the same. > > As I said I'm out of ideas, but it seems a problem with PA, is there anything that I can do to find the cause? sysfs.path = "/devices/pci0000:00/0000:00:1d.0/usb3/3-1/3-1:1.0/sound/card1 sysfs.path = "/devices/platform/bcm2708_usb/usb1/1-1/1-1.3/1-1.3:1.0/sound/card1" Seem snd-usb-audio on different platform have different constraints. (period time ms and period size ) W: [pulseaudio] sink.c: Default and alternate sample rates are the same. Seem you are using same rate for default and alternate sampleing rate It is strange that so many disable tsched mode but only one [pulseaudio] alsa-sink.c: Cannot enable timer-based scheduling, falling back to sound IRQ scheduling. I: [pulseaudio] alsa-util.c: Disabling tsched mode since BATCH flag is set I: [pulseaudio] alsa-util.c: Disabling tsched mode since BATCH flag is set I: [pulseaudio] alsa-util.c: Disabling tsched mode since BATCH flag is set I: [pulseaudio] alsa-util.c: Disabling tsched mode since BATCH flag is set I: [pulseaudio] alsa-util.c: Disabling tsched mode since BATCH flag is set I: [pulseaudio] alsa-util.c: Disabling tsched mode since BATCH flag is set I: [pulseaudio] alsa-util.c: Disabling tsched mode since BATCH flag is set I: [pulseaudio] alsa-util.c: Failed to set hardware parameters on plug:surround40:1: Invalid argument I: [pulseaudio] pcm_params.c: Slave PCM not usable I: [pulseaudio] pcm_params.c: Slave PCM not usabl Is is strange the error is slave pcm not usable instead of Channel count not supported Did you have same /usr/share/alsa/conf/cards/USB-Audio.conf? pulseaudio] source.c: device.description = "PCM2902 Audio Codec Analog Stereo" I: [pulseaudio] source.c: alsa.mixer_name = "USB Mixer" I: [pulseaudio] source.c: alsa.components = "USB08bb:2902" I: [pulseaudio] source.c: module-udev-detect.discovered = "1" I: [pulseaudio] source.c: device.icon_name = "audio-card-usb" I: [pulseaudio] alsa-source.c: Using 5.0 fragments of size 4096 bytes (21.33ms), buffer size is 20480 bytes (106.67ms) [pulseaudio] server-lookup.c: Unable to contact D-Bus: org.freedesktop.DBus.Error.NotSupported: Unable to autolaunch a dbus-daemon without a $DISPLAY for X11 W: [pulseaudio] main.c: Unable to contact D-Bus: org.freedesktop.DBus.Error. NotSupported: Unable to autolaunch a dbus-daemon without a $DISPLAY for X11