So I would agree my Zenth MKIIse with the PhoenixUSB (PN) clearly sounds better then the Pulsar without a PN. The PN fleshes out far more music density within the soundstage envelope. There just is a lot more going on from the musicians, and the music makes more sense, sometimes more musicians become more apparently within the mix. Without the PN, I was listening to a song, and it sounded like an acoustic guitar with perhaps some effects or reverb, trailing it. When I installed the PN, I could clearly hear that there were actually two guitars, playing in perfect pitch and harmony, and in tune with each other it was the same level of improvement (but not necessarily the exact same sound) adding the PN to either Innuos. This is about musical clarity and engagement. The PN, at least in my system also improved with the addition of a SR Purple fuse, and an upgraded power cord and the use of a second, same high-quality USB cable in the signal path. Unfortunately, on the PN side, the costs do add up. But also viewing from cost standpoint, if you have to add a outboard or server or NAS to play your files plus an additional upgraded power cord, Ethernet cable and possibly an upgraded power supply, that makes a pretty good case for a Zenith with everything in one chassis. I am not advocating for buying a five year old Zenth MKIIse, this is just my personal experience.