The information is the same as on the NFB-11 and NFB-12 pages from audio-gd homepage. So nothing new unfourtently =(
I previously mailed kingwa, about the different Power consumption and weight, and the same output power between the NFB-11 and FUN.
The main differences was that the fun had a larger chassi, Analog RCA input and customizable OP amps. The No-feedback design do not use OP amps.
The NFB-11/12 also same to have the same resistors as the FUN version A
So the difference should be quite small, if your not in the need of analog RCA or what to change sound with OP amps.
Besides the different in price 145USD….