@goofyfoot From reviews it appears that the new ISO Regen is better than the old Regen. I have not tried any USB regenerator except for the similar functionality integrated into the Sonore microRendu.
Dave,
Prior to SOtM, I was using a microRendu as an Ethernet end point, networked through a Cisco EN switch to a QNAP TVS-882 i5 NAS hosting Roon. Running on that i5 core, the Roon DSP engine upsamples and filters all sources to DSD128, then across EN through SOtMs to USB into Esoteric K-01X. The mR people don’t recommend an in-line regenerator, as the mR reportedly integrates features of the Regen. The SOtM people recommended the combo of all four pieces for the full SOtM experience... As I already had a 10mHz rubidium clock, the ability to synchronize to the master clock was conceptually appealing. Once it’s all broken in, to weigh up the relative contributions to performance I’ll begin subtracting components from the chain. This will include comparing the SOtM DC power supply to my Hynes SR7.
All I can say so far is that the improvement of synchronizing all clocks to several PPB precision is obvious.