If you are completely bypassing the Bose amp then you'd be better using small blade terminals plugged into the Bose connector. I do an RCA adapter for just this purpose, far easier to install and a guaranteed connection. Piggybacks are pretty hit or miss and the wiring in the Bose lead is very tight. Jus take an RCA cable chop it in half, strip back the insulation so you then have the 4 signal wires, and 2 screens then solder these to small blade terminals and plug these into the corresponding slots on the Bose plug. Then wrap it in electrical tape. It's fine to leave the amp unplugged.