going Pass Labs, do I need "Class A " ?

dear mr. peterayer,
i am going by one person who put his XA-0.5 100W mono blocks up for sale. a lot of people questioned his decision in the forums, so
he explained at length regarding his changing preference for
a different design. apparently he felt the bass was lacking something in his system even though i don't think it was a lack of power.
just for an example i have levinson amps which don't inspire much emotion-
that has to come from within. but they do reproduce bass about as well as it can be done. i would think a pass X-.5 amplifier properly matched to your speakers would do the same thing. and bass can have a dramatic effect over the sense of depth / 3-dimensionality of the stage. OTOH they might fall a bit short on reproducing textural details of acoustic instruments or sound a bit flat on a Diane Krall album.
i have only heard pass aleph amplifiers - the 30 and the 1.2 mono blocks.
they were beyond reproach to my ears, especially on piano and jazz.
but i never tried them out on Bach organ pieces where i might have been
less enthusiastic. but i am easy to please when it comes to this level of audio gear,
so i could go either way without a 2nd thought and learn to be happy.

Peterayer, I hope you and French_fries don't mind, but IMHO dollar for dollar: yes. Though there are other considerations too.

Mwilliams,

pre amp considered is Pass Labs XP-20.

In my present system there is ATC SCA-2 and I might as well keep it - !?

French_fries, So you haven't actually heard these amps? Why comment then?

Unsound, If you mean by "dollar for dollar: yes" one should buy the Class A Pass Labs amps, then I would tend to agree, though I'm sure there are situations where someone would prefer the A/B models. They do sell many of the X.5 amps.

Peterayer, no that's not what I meant. I was answering; "Yes, dollar for dollar" to the question: "French_fries, Are you saying the XA.5 have less control at the frequency extremes than X.5 amps?"