I sell Jolida, and Klipsch. Been messing with audio gear for years. The Heresy III speakers really only need about 5wpc to drive to any reasonable volume. Lower powered amps always sound the smoothest. Back in the day most of the best gear- Marantz, Pioneer, etc. made amps and receivers in the 25wpc to 45wpc. A 100+ wpc SS amp is way overkill for these. and you are just sucking juice from the wall socket. A Jolida FX10 amp, JD301BRC, or JD102CRC would work great. You can check out DECWARE amps- they make a 6wpc class A tube amp that would work great. If you insist on SS look at less then 75wpc, or even less than 50wpc. Yamaha might be good choice. Or Rega Brio R or PS Audio Sprout. Low powered amp with clean, smooth sound. The Jolida JD301BRC 30wpc hybrid amp with level one upgrade will sound better than either NAD mentioned- I would give you a money back guarantee on that. a 20wpc amp hooked to these would achieve volumes able to shake the pictures off my walls.
a Yamaha AS301 might sound better with these than either NAD mentioned. Get one of the Jolida amps and be real happy. And use less electricity. Bob Anderson