On 09/24/2014 09:30 AM, Dario Ernst wrote: > 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. Please test this with aplay, and make sure you're using a file that is in stored in one of the sample rates and bit depths the hardware supports natively. This is to rule out possible resampler problems. If that doesn't help, another debugging tip is to generate a wave file that contains a simple 16-bit up-counter as audio payload. Play this, and see whether you see a sane pattern with usbmon. If you can, tracing the data on I2S is also a useful way that would show you whether the USB stack in your device does the right thing. Daniel ------------------------------------------------------------------------------ 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
