I have the "i" version, and have heard the "r" as well, and imho, there was very little difference between the two, although I thought the "i" was just a tad more refined and quieter.
I love my Cary, have had zero issues with it over the last few years, and find it very musical and very listenable. I would think it would be a beautiful match with your 1b's - I used to run 2b's full range with this amp, and the lovely midranges were to die for, as they are now with my Audio Physic Virgos. And you always have the switchable Triode to UL in case you ever need more power.
I don't see how you could go wrong with this combo!
I love my Cary, have had zero issues with it over the last few years, and find it very musical and very listenable. I would think it would be a beautiful match with your 1b's - I used to run 2b's full range with this amp, and the lovely midranges were to die for, as they are now with my Audio Physic Virgos. And you always have the switchable Triode to UL in case you ever need more power.
I don't see how you could go wrong with this combo!