Rogue Audio Atlas Magnum III Power Amplifier

Your speakers have 3-ohm impedance in the midbass region.  

While they may sound god with the Atlas at moderate volume, the 3-ohm midbass region will tax the amp such that above moderate levels midbass will run out of steam.  

Can you stretch to the Stereo 100?  

I probably can. Will it be a match though? Both are 100 watts. Parasound is many more watts than the two. It makes me wonder if I am going to lose something going from solid state to tubes at a lower wattage. 

The Rogue amps perform really well from their 4 ohm taps into 8 ohm nominal speakers, so a 3 ohm dip shouldn’t be any problem when running from those taps. But the Stereo 100 should perform better overall, if you can go there.

100 Watts, even sacrificing a little of that for running 4 ohm taps into 8 ohms (this mismatch will generally sacrifice some power in exchange for lower distortion and better bass), should be enough for you 93dB speakers.

I like the A21 (owned one in the past) but I think the Rogue amps will be more enjoyable. They also bring a lot of flexibility for tube rolling, etc.