I would consider Krell as very high-end audio gear some really nice stuff
I dunno, in amps, the subject of this thread, I'm less than impressed. Yeah, their top of the line monoblocks are powerful, if you need over 600 watts per channel, but measurements-wise I'm not so impressed. Stereophile's measurements didn't reveal SOTA performance for 2020:
krell-solo-575-monoblock-power-amplifier-measurements
A 1-watt A-weighted SNR of -89db is not outstanding anymore. Output impedance is excellent, but distortion at 300 watts is less than 80db below the 50Hz fundamental. That's good performance, but a pair will set you back $22K at list price. I suspect a lot of this is due to the all-discrete circuitry. For low-voltage stages ICs really are better, IMO.
Krell's technical claim to fame, dynamically variable bias voltage for the output transistors, think of it like instantaneous Class A configuration based on input signal level, sounds cool, but the results don't seem to the justify the complexity, as they do with the feed-forward error correction of the Benchmark ABH2.
I'm thinking all of these old-line high-end companies are fighting yesterday's battles.