Many tube amps do sound fabulous on Quads. Though some solid state amps will perform well. I used Rowland amps every now and then on my Quads with gd results. I've used & owned a number of tube amps and I have owned several diff OTL amps. For the sake of quality control, reliability, and sonic performance, I prefer the Joule Electra amps over the Atmaspheres.
Historically, Quads thrived on power. Of course we are talking not just about amps with power but amps that combine power with high quality sonics. Power is not necessarily measured in watts as the lab created specs for watts usually is not indicative of power available in real world situations. Case in point, I'd bet a "little" less than 20 watt Viva amp would sound damn gd driving Quads.
If you do go for the Quads, have fun. They are fantastic speakers.
Historically, Quads thrived on power. Of course we are talking not just about amps with power but amps that combine power with high quality sonics. Power is not necessarily measured in watts as the lab created specs for watts usually is not indicative of power available in real world situations. Case in point, I'd bet a "little" less than 20 watt Viva amp would sound damn gd driving Quads.
If you do go for the Quads, have fun. They are fantastic speakers.