Never tried them with such a prestigious Class A amp. FWIW: I'd say 100 watts is fine but I would certainly not go any lower. I typically drove these little speakers with 200+ watts of Class AB. If you are considering the ATC's then I must warn you that you will find them bass light but very punchy/dynamic compared to most speakers. Midrange is forward (flat on and off axis through 1 to 5 Khz) so you'll also find them more attacking and more hardness/articulation on vocals than most designs which generally tend to a midrange dip. (think a smooth sounding horn but nevertheless a sound that can easily be regarded as "harsh" by some, especially at elevated levels and depending on your tastes)