Albert,
I am using the 1st Gen iFI iPurifier on my Allnic D5000 DAC with Audioquest diamond cables. I do find this to be a slight improvement than without the iPurifier. Interesting to hear your thoughts non the iPurifier 2. Not sure if you need the iUSB3.0 power since the D5000 does not need the 5v from the USB cable. SO, maybe redundant? Also, appreciate any comments you can give of the Allnic M5000 amp versus the ARC REF250 amps in your system.