Passive Mixer Circuit

Colby,

I need to liberate my Mackie mixer from the hifi and put it back in the studio where it belongs. Is there a passive resistor circit that I could build to feed the output of 3 sony changers into a single input on the amplifier?

If so what is the circuit and what should the values, resistor types be? I know it won't be as good as a real mixer, but no cash available for a replacement.

Thanks