Bought new receiver, Yamaha RX-V679.
Had an old 7.1 system.
Trying to use the active sub from the 7.1 system along with the new receiver.
The amplifier for the sub?? looks like this:
https://www.dropbox.com/s/xn2klgnyyh3l3ko/20151206_163824.jpg?dl=0
The back of the subwoofer looks like this...