I was experiencing this issue as well as periodic microsecond drops. I reported my issue to Alex Crespi, who exchanged it for a new one in early July. I believe there was a problem with the first batch of components, which was corrected when a fresh supply parts were used in the new ISO Regens. For me the problem was corrected, and I haven’t experienced any more issues with my previous dac or with my new DSJ, which I’ve had for only a few weeks. I am using the the LPS-1 linear power supply with the ISO.