I am new to the audiophile world. I have the ATH-M50 and the HD 598, with the Audioengine D1 as my amp/dac. My computer is a 2012 Macbook Pro. The D1 is powered through the front USB port. It usually works just fine, but I sometimes notice some problems: the sound will intermittently cut out, or there will be pops and clicks, and on one occasion the music "sped up" like those Chipmunks songs.
I tried different things to fix it, such us unplugging and replugging in the DAC, rebooting my computer, closing and re-opening iTunes, etc. I also tried changing the MIDI setting from 24-bit, 88.2 kHz to 24 bit, 44.1 kHz. (What is the optimal setting? All of my music is regular 16/44.1 on iTunes.) The last time this happened, I opened up the Task Manager and noticed that I was running very low on memory. So I closed all my programs and rebooted the computer, and the D1 worked just fine.
I suspect that it's a memory issue. Is that right? I don't think I have a defective D1, because I bought the floor model of a local retailer, and I doubt he would have kept it as his floor model if it were regularly having problems. (And I happen to know that he had it as his floor model for several months.)
Have other people experienced this problem?