dls wrote: > Thanks for your help on this. > > I'm using three separate identical USB DACs. My Thinkpad T60p has 3 USB > ports. The Lenovo specs for this model states that these are USB2.0. I > don't know how to determine if they are ports on the same bus or an > internal hub. > > I connected a USB DAC to each of the three USB ports. In another test, I > tried with an external, powered USB hub connected to one of the Thinkpad > ports. Both cases gave similar results. > > [EDIT] I've retested on the T60p with Lubuntu 14.04 (kernel > 3.13.0-24-generic). Problem persists > > [EDIT 2] I found lsusb. Using the usb ports on the Thinkpad it reports: > > david@david-t60p:~$ lsusb -t > /: Bus 05.Port 1: Dev 1, Class=root_hub, Driver=uhci_hcd/2p, 12M > |__ Port 1: Dev 2, If 0, Class=Wireless, Driver=btusb, 12M > |__ Port 1: Dev 2, If 1, Class=Wireless, Driver=btusb, 12M > |__ Port 1: Dev 2, If 2, Class=Vendor Specific Class, Driver=, 12M > |__ Port 1: Dev 2, If 3, Class=Application Specific Interface, > Driver=, 12M > /: Bus 04.Port 1: Dev 1, Class=root_hub, Driver=uhci_hcd/2p, 12M > |__ Port 1: Dev 2, If 0, Class=Audio, Driver=snd-usb-audio, 12M > |__ Port 1: Dev 2, If 1, Class=Audio, Driver=snd-usb-audio, 12M > |__ Port 1: Dev 2, If 2, Class=Human Interface Device, > Driver=usbhid, 12M > /: Bus 03.Port 1: Dev 1, Class=root_hub, Driver=uhci_hcd/2p, 12M > /: Bus 02.Port 1: Dev 1, Class=root_hub, Driver=uhci_hcd/2p, 12M > |__ Port 1: Dev 2, If 0, Class=Audio, Driver=snd-usb-audio, 12M > |__ Port 1: Dev 2, If 1, Class=Audio, Driver=snd-usb-audio, 12M > |__ Port 1: Dev 2, If 2, Class=Human Interface Device, > Driver=usbhid, 12M > |__ Port 2: Dev 3, If 0, Class=Audio, Driver=snd-usb-audio, 12M > |__ Port 2: Dev 3, If 1, Class=Audio, Driver=snd-usb-audio, 12M > |__ Port 2: Dev 3, If 2, Class=Human Interface Device, > Driver=usbhid, 12M > /: Bus 01.Port 1: Dev 1, Class=root_hub, Driver=ehci-pci/8p, 480M
That looks like you have two dacs on the same usb bus. It is only 12m so I would not necessarily expect that to work. Try moving USB ports or try using bus 01 which is 480m ------------------------------------------------------------------------ Triode's Profile: http://forums.slimdevices.com/member.php?userid=17 View this thread: http://forums.slimdevices.com/showthread.php?t=97046 _______________________________________________ unix mailing list [email protected] http://lists.slimdevices.com/mailman/listinfo/unix
