seek a threashold power amplifier


in the 80s,threshold sold a mono block power amps.one class a and one class a/b.i seek the class a/b to buy.maybe not available because none sold.do not remember tag or model name.it was listed as 1 horsepower at 8 ohms.look up watts horsepower conversion table.the class a and class a/b were indentical cabinets.huge.the current mcintosh labs power amps mc2kw are 2000 watts at 2 4 8 ohms.about 3 horsepower and cost a fortune.threshold less by a mile if burn time a year or two classical music.HELP?anyone out there knows anything about this power amplifier.i am trying to buy the pair.
goingnuts
Have the manual right here. Same # of per channel output transistors 64, same uF size power supply = huge .25 Fahrad (key is cap voltage rating), bias current almost identical 1.1-1.2 amps with the lower the 12e, same peak current output 200 amps (35 for the 1600e versus 70 for the 12e class A). This suggests to me that you can tap the transformer to change the voltage & I believe NP told me once it was possible for my S/550e. Ask him at diyaudio or ask Jon. If I saw one I'd buy a 12e but I think they're very rare and I've never seen a S1600e here.
Higher bias into class A results in a more sweeter sound also. That is why Nelson preferred the 60 Watt stereo SA3.9e. Relative to the other SA series Thresholds, it was biased higher into class A per watt.

Main issue is heat.
I've seen a few SA12e amps for sale over the past 5 years. Never a S1600e. But if you found the SA/12e amps, I think you'd be hard pressed to give up their class A sound just to convert them to 1 hp under class A/AB bias. I would think it more likely for an owner to go the other way. Perhaps that's why there aren't that many S/1600e amps out there.