Yes, Q5 is quite demanding but Q3? OK, Lamm M2.2 in low impedance mode with 220 watts into 4 ohms have absolutely no problem driving it (ok it is a hybrid). My local dealer tried Rogue monoblocks (120w, 150w? I can't remember exactly, into 8 ohms)and it also drives Q3 beautifully. My friend also tried Air Tight 90 watts monoblock with Q3 and it works like a charm. Personally I doubt the 10-20 watts SET would be able to handle Q3 well but good 100 watts tube amps are not out of the question for sure. Q7 is definitely easier to drive than Q3/Q5. I have not heard them with tube amps yet but with Soulution monoblocks, the volume was set quite a bit lower than Q3 ( abotu 40 vs almost 60 on volume dial). Plinius SA Reference in class A mode (100 watts) also work extremely well with Q3. I was the first person in my group to get Magico and now, I have 2 other friends with Q3 and one with Q5 so I definitely get to hear them with several different amps. Q5 is definitely harder to drive but with Q3 and now Q7, Magico does not automatically require super amps anymore. In fact my Lamm M2.2 have more difficult time driving Usher Be-20 than Q3 in my room.