Summing Resistor

A component inserted into the signal path of a mixer or other device to prevent unwanted interaction (“crosstalk“) between individual input signals at a summing stage. Resistors are made of material that opposes the flow of current, and a summing resistor is no different; its name merely denotes its specific application. The way it works is that all of the individual signals are sent through a summing resistor and then, on the other side of the resistor (which provides the isolation) the signals are simply combined at a common point (a bus), where they become one (mixed) signal that can be amplified and further dealt with. While commonly used at summing points in mixers, summing resistors are also employed in external summing devices.