Update to my last post, I got the Xantech LCD/CFL resistant dinky link and hooked up the interface module, success.

Two notes on the 794-10, I did have to ground the GND2 pin to the chassis, which I used the Phono ground for. Otherwise, the Pioneer would not work while the 990 would, but both work with the GND2 pin grounded to chassis. Lastly, the cables from the 794-10 output to the 990 IR Input and from the 990 IR output to the Pioneer IR Input are both 3.5mm stereo.