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.
My understanding is that they copied the original board design and the only changes made was to make the bandstand on end to make this layout in the small case.  As far as the Dartzeel, I looked very hard at these clones and almost pulled the trigger. Again, a basic amp design cop on the main output boards on this amp. The innards look very different than the original and I have seen 3 different boards on Dartzeel clones.
Sorry, band stand is circuit boards.... I'm out of town, auto correct on phone