I need a variable audio out to run a Logitech 5.1 system(stereo only not surround 5.1) out by my grilling area. The headphone jack works great for this but it shuts off the main speakers inside when a plug is inserted.I want the speakers to continue when a headphone plug is inserted. Does anyone have schematics for this unit? Inside the receiver which wire or wires on the headphone jack do I want to cut off the contact(that bypasses the main speakers) and reconnect together on another contact to keep the main speakers operating when a headphone plug is inserted? Thanks for any and all input.