When I first connected the new T20 tube preamp it was replacing a highly regarded full sized tube preamplifier for comparison. The T20 sounded pretty close, but when I installed the SPARKOS 3609 op amps the system sounded so good I decided to leave the heavy, full sized amp out of the system because it could not compare with the upgraded T20. I am using 2 Aiyima A70 monoblocks with 48v10A power supplies each. Denafrips ares 12-1 dac, Wiim pro streamer, SMSL Pl 200 cd player, and Dynaudio Confidence C2 speakers. The system sounded so amazing I ordered another T20 for a second system. The first order was at my door within two weeks of ordering. Great work Aiyima!