Triode wrote: > It has been reported elsewhere that tuning the kernel module parameter > nrpacks may have an impact on sound quality with EDO when using a usb > dac. > > This can be achieved by: > > echo NUMBER > /sys/module/snd_usb_audio/parameters/nrpacks > > Please note that if you try this tuning parameter there are two things > to look out for: > 1) The kernel we use will limit values of nrpacks to between 1 and 20 - > any values larger than 20 will be silently treated as 20 > 2) This parameter is only read at the time the usb audio device is > created. With EDO this occurs while the kernel is booting as we need to > have the device available for the squeezeplay application. I'm not > convinced at present that we can effectively change this parameter with > EDO in operation. I'll produce a test kernel to check this. > > Edit: Confirmed - nrpacks is only set when the usb device is detected. > With the current kernel we can set it to a value between 1 and 20 but > only if it is done before the usb device is connected/powered on, or if > the usb dac is turned off and on after setting the parameter. So to > tune this parameter at present will require manual tuning and then > turning off/on the dac which must also have been on at startup for > squeezeplay to recognise it. I am yet to be convinced of an impact on > sound quality, but I wanted to make sure people know how to tune it to > have any effect...
Hi Triode, back in the days when I was working with HRT streamer with my own hacked up jive_alsa and manually editing files I could definitely hear a significant difference in sound by changing nrpacks. If I remember correctly the default is 8, going lower improved the sound and going higher made it worse. The system still worked with nrpacks set to 1 and this gave the best sound of all. I haven't had time to try this with EDO yet, and it's probably going to be a few more weeks before I can get some time to try some of the recent optimizations. John S. ------------------------------------------------------------------------ JohnSwenson's Profile: http://forums.slimdevices.com/member.php?userid=5974 View this thread: http://forums.slimdevices.com/showthread.php?t=94855 _______________________________________________ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/mailman/listinfo/audiophiles
