I have not heard the Supratek, but I have compared the DCC2 preamp initially versus the Audio Note tube M-8 and more recently M-10 preamps. In both cases, and IMS, I much preferred the tubed preamps to the DCC2 preamp, although all were excellent. The AN tube preamps seemed to have more air, liveness, and depth to the soundstage to the music. As you know the DCC2 is an amazing DAC, thus the preamp is a bonus. I would recommend you try both in your system
Reg
Reg