Pass First Watt models ... confused


I'm curious about the First Watt products. I'm a very happy owner of a Pass x250.5 AB amp but interested in experiencing full class A. No plans to sell my less than 1 year old x250.5, and I'm not rich so I won't be sinking cash into the exorbitant prices of a new XA series. A used Aleph is a possibility, but those are getting fairly old and I wonder about maintenance issues.

Therefore I am looking at the reasonably-priced First Watt line from Nelson. But I'm quite confused by all the different models. Can anyone help clarify this puzzle for me? Thanks.
abrew19
OP-

can we get a list of loudspeakers that are compatible w/ these amps? Keep me posted & Happy Listening!
It will depend, amp by amp. The First Watt website should steer you well. As can the threads on DIY Audio, to which Pass frequently contributes. The 6moons reviews are also pretty informative. The info is out there.
Agree with Roscoeiii, each First Watt amplifier is unique. They have different design objectives and are not of equal utility with a given speaker load. Some models have NFB and others do not. Some are voltage sourced, others current sourced. 6 Moons has covered and compared each one of them comprehensively.
Charles,