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.