After installing ElCap public beta my McIntosh D100 is now inserting a 1 second blank into every 15 seconds of audio or so no matter what app is used (iTune, JRiver, Skype, Safari, ...). At first it wouldn't even recognize it properly or let me select it under Midi Setup but now at least that seems to work.
I tried my WA7 and that did not cause the 1 second blanks but had intermittent pops so it is at least somehow related to the specific DAC chipset Mac-side USB driver. I tried my HiFiMeDiy Sabre USB dongle with optical out to my D100 and that works fine no pops or blanks. So yeah it depends on the device driver specifically.
As well my library is on external USB3.0 HD via a Anker USB3.0 powered hub and I was able to get the WA7 to work without the pops by reading files from the internal SSD instead (2013 macbook pro maxed out specs). So not only are there specific driver issues depending on exactly what device you have but it seems to have bus sharing priority or clocking issues as well that may be fixed by reading your files from internal instead of external.
One thing I think I noticed is Midi Setup no longer allows me to select the clock source of my DACs whereas it used to let me select either of computer or device, now it only says 'default'. I believe the bulk of these issues is in this clock source non-selection. Probably assuming the computer's usb clock instead of the async DAC clock and starves out the buffer every 15 sec before it gets around to reloading it.
Currently using JRiver as my media player but have heard good things about Roon lately and am curious to maybe give it a shot. JRiver interface is kinda a bad form of funk for the Mac.
