On 28.09.2012 01:56, Jeffrey Barish wrote: > I am using a USB DAC (HRT Music Streamer II) which operates in > asynchronous mode. It works perfectly at sample rates up to 48 kHz. > When I go to 88.2 or 96, it works perfectly sometimes. Most of the > time I get ticks. When it starts playing without ticks, it will > continue to play without ticks to the end of the track. A different USB > DAC that operates in isochronous mode is able to play at the high sample > rates without problem. Which kernel are you on? And please post the output of 'lsusb -v'. Thanks, Daniel > The designer of the HRT DAC (who provides excellent support, by the way) > believes that the problem might be buffer underrun. Considering that > the problem occurs only at high sample rates, I can see some logic in > that theory. However, what I don't see is why playback works perfectly > all the way to the end of a track whenever it starts perfectly. If the > problem were an underrun, I would expect that at least occasionally the > buffer would underrun after a perfect start and I would start hearing > ticks midway through a track. Never happens. Moreover, I would not be > surprised were the ticks to vanish sometimes after a faulty start when > the computer finally catches up. Also never happens. Still, assuming > that the problem has something to do with the speed of the platform, I > tried exiting the desktop to reduce the load on the CPU (which, by the > way, has two cores that operate at 3.1 GHz). No joy. I also found that > the ticks occur just by synthesizing a sine wave using gst-launch: > > > > gst-launch -v audiotestsrc volume=0.01 ! audio/x-raw-float, width=64, > rate=96000, channels=2, endianness=1234 ! audioconvert ! alsasink > > The player uses GStreamer too, so maybe the problem is with GStreamer, > not alsa. So I tried a different player (sox). To play the track with > sox, I converted it first to wav. I still get ticks. Any suggestions? > Has anyone gotten any asynchronous USB DAC to work at sample rates of > 88.2 or 96 kHz? > > In case it matters, I am running Lubuntu 12.04. > > -- > Jeffrey Barish > > > > ------------------------------------------------------------------------------ > Everyone hates slow websites. So do we. > Make your web apps faster with AppDynamics > Download AppDynamics Lite for free today: > http://ad.doubleclick.net/clk;258768047;13503038;j? > http://info.appdynamics.com/FreeJavaPerformanceDownload.html > > > > _______________________________________________ > Alsa-user mailing list > Alsa-user@xxxxxxxxxxxxxxxxxxxxx > https://lists.sourceforge.net/lists/listinfo/alsa-user > ------------------------------------------------------------------------------ Got visibility? Most devs has no idea what their production app looks like. Find out how fast your code is with AppDynamics Lite. http://ad.doubleclick.net/clk;262219671;13503038;y? http://info.appdynamics.com/FreeJavaPerformanceDownload.html _______________________________________________ Alsa-user mailing list Alsa-user@xxxxxxxxxxxxxxxxxxxxx https://lists.sourceforge.net/lists/listinfo/alsa-user
