The YJhifi Audio only has a left and light channel input the bass channel was meant to power a sub. I just hooked up the sub speaker connection to my Paradigm speakers and only heard some bass notes come out.
I am satisfied with the sound from both the YJ Audio and the FX Audio amps, they sound very similar. I would be hard pressed to tell the difference between the amps sound wise.
These do seem to be superior in sound to the 3116 amps I was using in my office system before.
-Has blue tooth connection
-Can power a subwoofer (unknown crossover point)
-Theoretically more powerful than FX audio fx502s pro (depending on your power supply)
-The YJ audio has an annoying pop when powered on (I think it switching between bluetooth or line connections).
-volume pot feels cheap, has some rough spots when turning
-doesn't come with power supply
-need to kill bluetooth connection for line inputs to work (no manual switch on unit)
-no tone controls (a negative to some)
-smoother volume, has larger knob
-Has digital power switch
-can play with op amps
-comes with a 24v 4A power supply