Hello dear Alsa-List, i have built a "Jedac", a DIY-USB DAC consisting of TI/Burr-Brown PCM2707C for USB interfacing as well as the PCM1794A for the actual conversion. The original author has some more documentation including schematic and PCB-Layout here: http://users.abo.fi/jskata/JEDAC/ I've been using the DAC for a while now. Recently, i've noticed that i get a slight "crackle" in the background. Only when listening to music. It sounds ... a little like a bad, old Vinyl. A slight, medium- to high pitch crackle. Its most audible in quieter portions of the track, but i'm pretty sure its also existent in the louder parts, just that the human ear has a harder time picking it up there. Anyways, on to my setup. While i currently use pulse (please don't start to run away screaming now!), i've completely purged and deactivated all pulse components for testing, and only used plain alsa. I've run alsa-info.sh and uploaded the result to your upload-service. Please see here: http://www.alsa-project.org/db/?f=43646f24d54c2d65841ae36ff44670bcb6321145 It also shows my onboard soundcard, which i don't use, as well as the "freshly" plugged in "BurrBrown from Texas Instruments USB AUDIO DAC". While i currently use kernel 3.16-2, i've also tried an older version where i could still set nrpacks=1. I've tried autoclock=0/1 as a module parameter as well as power saving in the older versions. I also use "powertop" every time to make sure the USB autosuspend is turned off for all USB-related devices (this is a desktop, but still, powertop has a nice interface for such things :D). I'm now at a total loss of ideas. A nice fellow in #alsa (@Freenode) suggested i either mail here, or try to use "USBMon" for debugging the problem. After a fair share of reading into USBMon and general USB debugging on Linux, i don't think i have the necessary protocol background to be up to the task. So, i'd be really really grateful for any help on finding and possibly solving the issue. Thanks for reading, and Best Regards -Dario Ernst PS: Please excuse my bumpy and broken english. As its not my native tongue, i'm always struggeling a bit :D. ------------------------------------------------------------------------------ Meet PCI DSS 3.0 Compliance Requirements with EventLog Analyzer Achieve PCI DSS 3.0 Compliant Status with Out-of-the-box PCI DSS Reports Are you Audit-Ready for PCI DSS 3.0 Compliance? Download White paper Comply to PCI DSS 3.0 Requirement 10 and 11.5 with EventLog Analyzer http://pubads.g.doubleclick.net/gampad/clk?id=154622311&iu=/4140/ostg.clktrk _______________________________________________ Alsa-user mailing list Alsa-user@xxxxxxxxxxxxxxxxxxxxx https://lists.sourceforge.net/lists/listinfo/alsa-user
