@carlsbad2 wrote: " The MU1 has the ability to take an analog input and switch it through to the analog output. I assume that is what you are referring to. but it is just a convenience switch, not a preamp. That assumes I understand it correctly. I haven't used it."
This understanding would not be correct according to Grimm which state the following: "The MU2 combines a music streamer with a superb DAC and a reference quality analog preamp."
Numerous reviewers have commented on the quality of the preamp in the MU2 as well as the inbuilt DAC. It is an MU1 and much more.
I use it as a one box solution from Ethernet to my amp. It sounds superb as well in my opinion and better than many of the separates which I have used.