Total posts : 45366
Great point Neil.
I’ve used this circuit (adapted from THIS ARTICLE) to combine stereo output into a mono input with a passive circuit.
I have also used resistors of lower Ohm values for inputs and outputs lower than line level.
1/8th watt resistors seem to work OK at low audio power levels
The circuit seems to work equally well as a splitter or a combiner.
Experimental broadcasting for a better tomorrow!