i used my 901 with the preamp section of a PS Audio integrated amp for a while, but recently switched over to my old Prometheus transformer based (TVC) preamp that'd been sitting in a closet for the last six years. Wow! With the Virtue it puts out a rich, organic, almost tube-like sound. I loved the Virtue alone, but the Prometheus takes it to a whole new level. I'm glad I thought to try them together but didn't anticipate anything like this. Too bad Nicholas at Prometheus self-destructed. He really made some excellent equipment at real world prices.
I'd like to hear other's experiences using a preamp with the Sensations. I know somebody here was happy with a Decware unit that I had thoughts of trying, but won't now.