Thanks for the reply, Daniel. Yes, switching the Benchmark DAC2 from UAC 1.0 to 2.0 is done in hardware. No Mac OS X drivers or any other software needed to operate in UAC 1.0 or 2.0 modes. Works natively in Windows in UAC 1.0 mode, uses Benchmark-supplied driver for UAC 2.0 mode. Nothing about this driver looks remarkable to me, except that it provides the means to upgrade the DAC's firmware. I have added more files Dropbox: https://www.dropbox.com/sh/eq9ed280i1kka4a/hSsAYhyRJ7 The file "dmesg_uac2_success.txt" in particular may be of interest: I plugged in DAC2 and repeatedly issued "sudo dmesg -c" as it initialized, and as you can see, it initially appears as a UAC 1.0 device, then disconnects, reappearing as a UAC device. It's consistent with the behavior that I see in the Gnome and Windows control panels. But more often, I get what you see in "dmesg_uac2_fail.txt" Thanks, Jeff -------------------------------------------- On Wed, 7/10/13, Daniel Mack <zonque@xxxxxxxxx> wrote: Subject: Re: Benchmark Media DAC2 HGC iffy USB 2.0 audio To: "Jeff S" <four_season_photo@xxxxxxxxx> Cc: alsa-user@xxxxxxxxxxxxxxxxxxxxx Date: Wednesday, July 10, 2013, 2:15 AM Hi Jeff, On 10.07.2013 06:59, Jeff S wrote: > Hello, I'm having difficulties getting my brand-new Benchmark DAC2 > HGC to work reliably. I think it's supposed to be a USB Audio Class > device, and it runs w/o additional drivers on Mac OS X just fine, and > under Windows using Benchmark Media's drivers for USB 2.0 audio. According to the descriptor dump, it is. > But under Linux, it doesn't seem to work at all in USB 1.0 mode: Is there a hardware switch to select one of the two modes? > Seems to be recognized OK but shows no output device in the Gnome > sound configuration utility. What does 'cat /proc/asound/cards', 'aplay -l' and 'arecord -l' say? > In USB 2.0 mode, it's iffy, often briefly showing up as a USB 1.0 > device, You mean UAC1 I take it? What makes you believe it's coming in that mode? > then disappearing from the Gnome sound configuration tool > altogether. It behaves similarly in Windows, initially showing up as > a 1.0 device, disappearing, but reappears as a 2.0 device a few > seconds later, and under Windows, it works fine every time. Sometimes > if I plug the DAC into my Windows notebook first, then plug it into > the Linux box, the DAC will show up as a USB 2.0 device, and will > work great, at least until I power it all down. It might be worth looking at a USB trace during the Windows driver start-up. Maybe they send some vendor-specific magic, which we could easily replicate in Linux. But you say that you didn't install *anything* under OS X? Not even some sort of configuration tool? > Currently using Linux Mint 15 (Mate) 64-bit w/Kernel 3.8.0 and > libasound2 1.0.25-4ubuntu3.1. > > Results of lsusb -v in both USB 1 and 2 modes are here: > https://www.dropbox.com/sh/eq9ed280i1kka4a/hSsAYhyRJ7 Please also post the kernel messages generated by the driver probe. An easy way to do this is running 'sudo dmesg -c' before and some seconds after a device hotplug. Best, Daniel ------------------------------------------------------------------------------ See everything from the browser to the database with AppDynamics Get end-to-end visibility with application monitoring from AppDynamics Isolate bottlenecks and diagnose root cause in seconds. Start your free trial of AppDynamics Pro today! http://pubads.g.doubleclick.net/gampad/clk?id=48808831&iu=/4140/ostg.clktrk _______________________________________________ Alsa-user mailing list Alsa-user@xxxxxxxxxxxxxxxxxxxxx https://lists.sourceforge.net/lists/listinfo/alsa-user
