Class A Solid State Sound


Would someone kindly describe the differences in class A sound of Pass XA.8 series, Accuphase A-70/75 series, and Gryphon class A amplifiers. Does much or any of the differences relate to mosfet (Pass and Accuphase) or bipolar (Gryphon)  output devices?  Thank you!

audiobrian
Post removed 
Why hasn't anybody spoken about Boulder amps. They are class A with sliding bias which for some unknown psychological reason I am uncomfortable with. Of course 250 large for a set of boat anchors is a bit steep even if your floor can support them. Next model down the 2150 at 100K is a direct competitor to the Pass Xs 300. Anybody ever hear a Boulder amp? Why would one buy it over the Pass?. 
Oh and George, a 200 watt class A amplifier conceptualized by a Danish
Graphic Arts guy and designed by teams of worker bees resulting in......?
I would prefer the work a dedicated electronics engineer who puts his reputation on the line with each amp preferably American. I would never even look at a Gryphon. Too much invested in flash resulting in rather silly looking stuff. Sound and durability are all I am interested in spending money on.