finally got my hands on one of these babies to replace my M51, came with power base and quad usb and spdif interfaces on the second hand market.
Prior to this upgrade I was running my macair into a jkenny spdif converter to reduce noise but using the USB direct into the MSB DAC is now 100% OK. I did have a slight noise issue using direct usb at first but replaced my 5 dollar usb cable with another equally cheap usb cable and the noise went away.
Although the jkenny was very much needed with the m51 to my ears, its not needed with the Analog DAC because to my ears direct usb sounds better, fuller i guess.
its only been in my 2 chan rig for a few days so far but i am very happy already with the upgrade. I will comment further in a month or two after i give it the full run in and pump it with all formats i can get my hands on including DSD which is new to me.
thanks for posting all the feedback!
Oh here in the money shot for all you fiends