I had a CJ CT6 preamp that I matched to a Threshold amp and the synergy was something special, I really enjoyed the combo. So if wanting something more modern than a Threshold, look at Coda which was started by some of the Threshold crew or Pass Labs, Nelson also was involved with Threshold. When I went with Pass components I traded my CT6 so never got to hear it with a Pass amp. I suspect they'd be great together as Pass is a very musical solid state piece. Pass offers stereo Class A/B that run Class A up to a point before switching to B, and they have Class A monoblocks.