What is the best premp for Atma-Sphere MA-1 3.3 amp?

I don't listen at rock concert levels. Some people have recommended Pass X350.5 for SL because of its "tubey" sound despite being SS. But as Ralph at A-S stated, at bass frequency, impedance is 30 ohms and X350.5 is only putting out about 90 W. SS is fine with me, but it seems to me MA-1 will give more even SQ across the frequency range. Of course, X350.5 is giving out 350W at 8 ohms in the frequency range where most music lives and is therefore much more powerful than MA-1. Then the question is whether I need 350W in the flat portion of the impedance/frequency curve if I don't listen at rock concert levels and my room is medium size 400 sq ft. What do you all think?

@OP,
In my limited understanding of such things, amplifier power ratings are for ballpark estimations of a speakers demands/capabilities.
The real issue is how well an amp can handle transient power demands. Which is why I lean toward having an amp leaning toward the higher power ratings.
Your speakers are rated for 50-500 wpc. Both the Pass and Atma amps fall nicely in the middle. And, given how Mr. Pass tends to underrate his amps, I bet they can put out a bit more power without issue of clipping or distortion.
Now, the reality check:
Unless you are really cranking up the volume, I doubt you will be using more than a few watts with normal listening.

So, why get an amp with 140 or 350 wpc?
Like I said, it is the ability to handle the transients within the music, and not taxing the amplifier to the point where it introduces distortion.
Like I said, I am no expert, so there will probably be some disagreement.
Perhaps Almarg can provide a better description. He knows and can write a very clear explanation, if anyone can.
Bob

thanks gdnrbob

May be people with experiences in both tubes (especially Atma Sphere) and Pass Labs can chime in. In <40 HZ, A-S MA-1 is more powerful than Pass X350.5 (for Soundlab), but X350.5 is more powerful than MA-1 everywhere else. Did I get this calculation right?

Obviously MA-2 would be a great solution (220W), but it is mucho $$$$ especially if I don't listen at rock concert levels.

@chungjh are you buying new or lightly used?

used. Looking for value.