Has anybody bought or heard a Chinese knock off amplifier?

On this topic, I would trust millercarbon. He knows where the value is and is deep into admiration of Chinese products' sound.

Millercarbon's System - Virtual Systems (audiogon.com)

Before moving up to a Bob Carver Crimson 275, I bought a new Muzishare X-7 integrated amp on Amazon to see if I even wanted to get back into tubes. I have seen enough crap electronics in my time to know good from bad, and I was very impressed with the build quality and the components used in the Muzishare. It also sounds great. I have no idea what the clones look like, but there is some pretty respectable gear, like the highly rated Line Magnetic Audio coming from China. There are quite a few reviews out there that back that observation up too. As for getting fooled by a clone, the same adage applies to name brand audio gear as anything else; If the price is too good to be true, beware.

Be a patriot...do not support the CCP...buy American made products or at least those made in non-communist countries.

Non communist.   You mean like Brazil, Poland, and Hungary?

There are a couple knock offs that do the job. Not quite as good as the real ones but none the less they are ok. The Bad News.... Pretty difficult too get  repaired if needed. If they fail (amplifier 's) they usually take down a good part of the unit leaving you with a boat anchor.
If you have 1000.00 to toy around with The DartZeel is pretty cool.