JohnSwenson;664119 Wrote: > I finally got some time off and have been working on this the last > couple of days. I put some wave files on an SD card and have been > trying aplay. I still get ticks and pops, but not as often as when > playing from squeezeplay. I tried killing jive_alsa and jive so there > was not much going on and that didn't make much difference. > > I also did a lot of work playing around with different thread > priorities, especially the USB driver and that made almost no > difference. > > I also tried many different alsa buffer properties through aplay > switches and was never able to get it any better. I can make it worse > by playing with these parameters, but I can't make it better. > > So the issue is not just something to do with squeezeplay, its in the > alsa/USB driver hierarchy. I'm not getting any xruns from alsa so it > might be something to do with the generic USB driver. > > Leaving the priorities alone and going back to squeezeplay the rate of > clicks and pops goes up significantly for 44.1 and 88.2, much lower for > 48 and 96. This sounds like a difference between internal and external > clocks, which would mean that the async is not working right. BUT when > using just aplay there is no difference in the rate of clicks and pops > with different sample rate. Async is handled in the alsa usb audio > driver so it should work the same from either squeezeplay or aplay. > > I also ran the Touch with my hacked in much newer alsa USB audio driver > and got the same results, so I don't think its an issue with the async > handling. > > At this point I'm running out of ideas. 44.1 and 88.2 are much worse > than 48 and 96, but I can't figure out why. > > With aplay I still have clicks and pops, but I don't know where they > are comming from, thread/interrupt priorities don't seem to be the > issue, neither does buffer size. I also tried different nrpacks and > that didn't make any difference to the click/pop behavior. > > Does anybody else have any thoughts for possible places to look? I'm > kind of at a standstill right now. > > John S.
Hi John - Don't know if this will help at all, but here goes. :) On a Mac running Snow Leopard, the Wavelength and many other USB DACs will do the same darn thing (snap! crackle! pop!) when running with player software that runs in what is known as "Integer Mode." -Only- when running in Integer mode, and -only- when connected directly to a Mac USB port. Putting a hub (or better yet) a powered hub between the DAC and the Mac removes the problem completely. I have heard from people whose opinion's I generally respect that this is a hardware bug in the USB port on the Mac, and it may well be. But sometimes I wonder. Unfortunately, putting a hub between the SB Touch and the DAC makes no difference at all, even though I fully and completely expected it to. I'm trying to figure out how to turn off the wireless connection and run it totally from ethernet, and vice versa to see if either the wireless or ethernet port if doing bad things to the power line on the USB port, but that is about all I can think of. It is such an achingly beautiful solution and combination that there just has to be an answer somewhere. I am a bit afeared it lies in the hardware though. -Paul -- paul.raulerson ------------------------------------------------------------------------ paul.raulerson's Profile: http://forums.slimdevices.com/member.php?userid=50346 View this thread: http://forums.slimdevices.com/showthread.php?t=82110 _______________________________________________ Touch mailing list [email protected] http://lists.slimdevices.com/mailman/listinfo/touch
