Older PURE CLASS-A Amplifiers


I am looking at some older Pure Class A amps and am curious as to are they as good as some newer amps like the Pass X150, and which ones are recommended, and have they been compared to each other anywhere? Thanks much for the recommendations.

I am considering the following PURE CLASS A amps:
Threshold T-50
Monarchy Audio SM-100 Monos
Monarchy Audio SM-70
Forte Model 4
tpk123
The SM70 has been discontinued. The SM70Pro is still a current product. The SM100's were replaced by the Se100's. Monarchy is very slow to update their webpage. I was trying to purchase a second SM70 about two months ago. I called Monarchy and they informed me that it had been discountinued.
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I am looking to drive Platinum Reference 1 monitors, similar to the Solos. They are very power hungy, so I guess I would need at minimum 50 watts. I liked the Monarchy cause it looks like they double down with each increasing ohms load.
I second Ramy here (Gryphon DM100), the only caveat would be the intensive wear that class-a design brings to output transistors, Is there any technical trad-off in that?

Regards,

Fernando