I've had 4 different pairs of Reference 3A's, the first three were de Capo i's, and now my current 3A Episodes. They are not fussy at all about amps, and sound great for me with everything from small 3 w.p.c. battery powered Tripath amps, Peter Daniels gainclone amps, 12 w.p.c. S.E.T. tube amps, my current Ayon Spirit II tube amp, Pass Labs J2 and even better on my Job 225 by Goldmund.