To your original question: I have had both a Nucleus Rev A and now a Nucleus One. I purchased the Rev A in 2018 and was amazed at the sonic improvement over running Roon on a MBP I was using at the time (see other AG posts of mine for more details). In 2024, it become flaky, shutting off by itself, not booting up unless it sat for a couple of days. I took it apart and eventually installed a new CMOS battery, but that did solve the problem. Roon thought it might need a new motherboard, weren’t even sure they had anymore, and replacing it would cost a couple hundred more dollars than a new Nucleus One . So I waited and bought a Nucleus One.
In the meantime, my big system had been down due to needing new tubes for the ARC REF150SE, so I have not directly compared the sound of the two, but functionally the One is identical to the Rev A. I laugh when I see Rev A, and Rev B’s priced more used, than a One, with a warranty, is new. I would only buy a One at this point. One trade-off the Rev’s have nice metal cases and the One’s case is plastic. But it does not get hot.
-docknow