Thanks! I mistakenly thought that the value of bcdUSB only reflected the maximal capability as read from the device. And in fact speed given in /sys/bus/usb/devices/.../speed also corresponds to usb 2.0. So my problem definitely not linked to bandwidth (moreover, the dac sounds fine at 16/176.4 which would require at least the bandwidth of 24/88.2). But oddly, 24bit resolution is ok @44.1kHz. Best, Rutger. On ven., 2013-12-20 at 15:12 +0400, Vladimir Mosgalin wrote: > Hi Rutger Noot! > > On 2013.12.20 at 08:23:55 +0100, Rutger Noot wrote next: > > > I didn't make any progress on this, except for finding out on the web > > that the TEAC has some firmware quirks (supposed to be handled by recent > > kernels). It appears that the teac driver is indispensable in windows to > > get the device running usb 2.0. Is there a way to find out (under linux) > > if the audio device is configured as usb 2.0 ? The usb subsystem also > > detects a HID device (which is usb 1.0 ??). If the audio is treated as > > usb 1, this would explain a lot. > > Run "lsusb -v", find your device in output - bcdUSB parameter is > version. E.g. > > Bus 002 Device 005: ID 20b1:0002 XMOS Ltd > Device Descriptor: > bLength 18 > bDescriptorType 1 > bcdUSB 2.00 > bDeviceClass 239 Miscellaneous Device > bDeviceSubClass 2 ? > bDeviceProtocol 1 Interface Association > bMaxPacketSize0 64 > idVendor 0x20b1 XMOS Ltd > idProduct 0x0002 > bcdDevice 3.30 > iManufacturer 1 XMOS > iProduct 2 XMOS USB Audio 2.0 > ... > > (Ignore iProduct here - that's just device name, but as bcdUSB shows > it's working in 2.0 mode) > > > By the way, USB 1.1 has quite enough bandwith for 24 bit / 96 kHz > output. I did that on my older M-Audio Audiophile USB. It's just that > you can't go higher than that, or can't record + playback at the same > time. USB 2.0 is only strictly required if you need 24/192 or more than > 2 channels for 24/96 or more than 4 channels for 24/48. > ------------------------------------------------------------------------------ Rapidly troubleshoot problems before they affect your business. Most IT organizations don't have a clear picture of how application performance affects their revenue. With AppDynamics, you get 100% visibility into your Java,.NET, & PHP application. Start your 15-day FREE TRIAL of AppDynamics Pro! http://pubads.g.doubleclick.net/gampad/clk?id=84349831&iu=/4140/ostg.clktrk _______________________________________________ Alsa-user mailing list Alsa-user@xxxxxxxxxxxxxxxxxxxxx https://lists.sourceforge.net/lists/listinfo/alsa-user
