I have seen the Rhea but not seriously auditioned it. I have heard it, and it does sound good, but can't comment on the specific A-B.
One thing I will say, though, is that the IO produces a stunning amount of heat. I had always heard that tube gear produces a lot of heat - I've got a Counterpoint SA-11, so I have a pretty good idea! - but just sitting next to the rack holding a 3-box IO and the preamp (Castillo, I think) was an eye-opening experience.
One thing I will say, though, is that the IO produces a stunning amount of heat. I had always heard that tube gear produces a lot of heat - I've got a Counterpoint SA-11, so I have a pretty good idea! - but just sitting next to the rack holding a 3-box IO and the preamp (Castillo, I think) was an eye-opening experience.