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
Look for the rare Pass Labs Aleph 0s (40W pure Class A)stereo power amplifier. This was one of the most natural sounding power amps I have ever heard. I am always looking for one ever since I heard the Pass Aleph 0s years ago. By the way the Pass Aleph 0s is one of Nelson Pass's favorite amp of all time. I talked with him for about an hour one day and he told me if you can find a Aleph 0s make sure you grab it.
I second the Classe DR-3B. A friend of mine had one for a short while and I told him to never sell it. It was one of THE best amps I have ever heard IMO. His speakers were relatively ineffiecient so he sold it. I couldn't swing owning it at the time.
Krell KSA-100MKII - one of the best balanced and mid ranged voiced amplifiers of all time. Caveat- You must send it in to be serviced every 15 or 20 years! Power supply caps need to be changed as they dry out - degrading sound & bass performance. Highly recommended - if you can find one.
Bedini 25/25. If you can find one, buy a lottery ticket the same day. The 25/25 continues to astonish me!
Luxman M-05. 105 watts per channel of the absolute most beautiful Class A power that can be found anywhere.