Benchmark makes great electronics that are transparent and are great for studio use. They measure well too. But that doesn’t translate to being the right fit in a home audio system. I’ve owned few benchmark DACs over the years and they never stuck around for too long including the latest DAC 3 HGC. I can totally see how these components can serve well in a studio environment but to me they sound slightly clinical and cold.
I never auditioned Benchmark amps so I’m just going out on a limb here to assume their objective was the same as with their DACs.
Also, interesting information…Benchmark amp is 11.04" W x 3.88" H x 9.34 " D - Including feet and binding posts and weighs 12.5lbs.
PS Audio BHK amps weigh over 80lbs.
There’s absolutely no such thing as giant killers. There’s no magic. You get what you pair for.
Between the two choices if I had to buy without listening would be the PS Audio BHK Mono Amps. You have a dedicated mono design, tubes, excellent power supplies.