I cannot recall who and when, but someone here on the Gon said in an earler thread that he had bought, and was using, the Chinese DarTZeel amp, and it was the best he had ever had.
The member who owns the Dartzeel clone goes by jaynewt. He replaced MBL 9008A amps with it and is driving a pair of MBL 101-D’s. Here is his system:
https://systems.audiogon.com/systems/5351

FYI I spoke with someone not long ago who had heard both the Dartzeel and the Douk Audio clone side by side and he said while the clone wasn’t as good it came surprisingly close.