Nrchy,one thing I did not mention,and you may want to(actually should)consider,is the "ergonomic" aspect of everyday use,regarding heat dissipation.Believe me all of the experienced guys in my little part of the world take it SERIOUSLY!
Tube units can be fabulous,and I too lust for the IO/Callisto combo,but the heat given off by these,and other units do not make life very pleasant in summer heat.With a full blown unit like the Io/Callisto you are going to increase the room temp considerably,not to mention the electric bill.Even with A/C,like I have in my dedicated room,I used to sit in my "Speedo" in the dead of winter when I was more tube oriented.Trust me --the kids at "trick or treat" time thought I was in an "Olympic Diver" get-up,though their parents thought I was weird,and all I wanted to do was listen in comfort!!Now I have moved to,only a three tube phono section.These considerations should be looked at,although my extreme example may be a bit overboard,though true(except the "speedo" at Halloween,I just wanted to be a bit creative).I do have some Tube loving friends(entire system,and obviously a tubed phonostage is not a real heat banger,except the Io/Callisto pre/phono)that will not listen in summer,sadly,as they have a few dozen tubes in the set-up.That's what drove me from a tube amp to my Rowland.
I know we are considering a phono section,but when conditions are right a tubed unit can put out enough heat to force a "speedo" on a Harley guy,like you!Best of luck.
