Totally concur with George-hifi.
ML-2 is a legendary amplifier without peers - really.
Not only can it compete with modern designs (2020), it’ll subjectively and objectively outperform 99% of them.
Sonics far superior to anything of the time (70s) from Threshold, Krell, Phase Linear, Harman, Marantz or anything else. Phenomenal build quality & design.
ML later opted for far more complex, massive no. of gain-stages, massive feedback circuits and so was the magic of ML-2 gone forever.
Problems? Low power - read: low sensitivity speakers playing in large, deadening rooms, 25W in 8 ohms is not gonna cut it.
I know some who’ve modified them for higher power, but you’ll need electronics knowledge and tools to do it, so not recommended for John Doe.
I’ve heard a cpl of Chinese clones... they’re not even close, so don’t bother. In one word: If you find one = get it !!