There is a possibility of problems with using a simple Y-cord. It's generally not a good idea to feed a signal into an output, especially when the circuitry of the output being fed has its power on, which would definitely be the case with the demodulator being used, and would be the case when using the digital output with the demodulator still powered up.

There's a reason switchers are out there, otherwise everybody would simply cascade multiple devices into a single input using Y-cords and connectors. Good luck, and let us know how the Spiky-method works.

Larry