Stereo / Mono Splitter - Combiner Pad
The schematic shown to the right is a simple stereo to mono (L+R) combiner pad for 600 ohms circuits. It can also be used in reverse to properly feed a stereo input from a mono source. When properly terminated it provides a good deal of isolation between the channels. This circuit can also be used to provide an L-R feed from a stereo source. This can be accomplished by reversing the phase on one of the stereo inputs.