Has anybody bought or heard a Chinese knock off amplifier?

The "barely surviving" industry have themselves to thank for it. They chose to charge absurd, wild markups and content themselves with super high profit margin but low production. Those that have been trying to serve the lower end market decided to do so by pushing their class D junk.

@hiendmmoe 
I bout one expensive, very heavy “Accuphase inspired” China class A amp, which has different China Brand name on it. I inspected components inside, tested it for distortions, output impedance etc, and I didn’t find anything wrong with the amp. Amp has two 700VA toroidal transformers, feeding two separated power supplies for left and right channels. Amp is using Japan made electrolytic, well matched US made power transistors (40 total), and CNC machined enclosure. Amp is NOT Accuphase replica or copy, it has only Accuphase feel. Overall outside look and details are less refined comparing to Accuphase. Internal boards built of expensive “black” material, wiring and layout is very good. Amp has no noise, acoustically and from the speakers, and it is not possible to tell if it is on or off without looking at power LED.
Comparing to original Accuphase class A amp, it sounds little bit more beefy, but little bit less transparent at high freq. end. It beats many US/EU amplifiers, even significantly expensive ones.

To summarize: there are good, very good and bad things come out of China, it is a lottery! 

The OP asked about knock-off products, not products made in China! Apples and Oranges!

Knock-offs can be products that have a confusingly similar overall appearance to the copied products but knock-offs do not contain any identical logos or federally registered brand names. Fashion knock-offs are legal in the U.S. but a counterfeit is not.

Its all Trumps fault !

hiendmmoe  I must respond:  Yes, China is beginning to sends rovers to extraterrestrial bodies.  There are no parts available to US (or British, etc) designers that the Chinese cannot get, especially since they manufacture for many American companies.  You would have to be racist to think they cannot do this.  Admittedly, at one time I fell in this category by thinking Japanese cars and racers would ever compare to AMURRIKUN, but we live and learn.  We should not wonder if the Chinese can, bur why they do what they do.  When a Chinese product is truly good, the company will proudly market it.  If it is a POS, it will have someones else's brand on it.