Good Morning,
I have a T8 and 550 on order and I was getting a little anxious that I settled for 2nd best. Back in the "T8" thread Frank describes both preamps and a couple of other Audio Circle members that were at RMAF where they heard both preamps describe their differences very similar to Frank. Also at RMAF, before they swapped out the Ultra and T8 on the flagship Salk's, they had the T8 paired with the U70 driving Salk's #2 speakers. IMHO upgrading to the Ultra DAC would be an upgrade where T8 to Ultra would be like changing a NY steak for a Ribeye, more of a personal taste between two excellent items. I have to go eat some breakfast now, suddenly I'm very hungry.