I run an M-Audio Delta 44 in my home studio and i recently bought some active monitors that i run out of ouputs 1/2 on my Delta. I still have outputs 3/4 free and i would like to be able to run a headphone amplifier off of these free outputs. However, I'm having much difficulty getting all four output ports to operate at the same time. I've tried all sorts of combinations with my ASIO control panel but i still cant seem to get all four working at the same time...can someone please help me out?

thanks...