The eight watts of my 300B SET amp will power them to levels that begin to realize this potential. I also tried them with the 3.5 watt 2A3 Paramours, and these are fine if you listen only to jazz, acoustic music, and early classical, but they begin to sound congested with highly dynamic music at room filling levels. I haven't tried any higher power tube amps yet, but I expect about 25 tube watts or 50 solid state watts is all the power you would want.