Years ago I had a nice Threshold T200 that claimed Class A but was a terrible match for MartinLoga SL3s so I sold it and kept looking, mostly AB stuff.
Then I picked up a W4S STI-1000 and for good or bad it seems to power my watt-hungry speakers superbly with zero noise and a good tonal balance, not fat.
And I put recently acquired used W4S SX-500 monos on the old SL3s (now in a movie room) and those 10" woofers never spoke so authoritatively.
If I had enough money I'd love to try a big Class A amp because my speakers shine better with more clean power. You'd need the money for electric as well if you leave the amps on. I noticed our power bill drop when the old McCormack DNA-1 was turned off and pulled out of one system.