Stereo mute button - with LED

Design for a stereo mute button with LED indicator when muting. Uses a simple DPDT switch (so the two switches in the schematic are toggled simultaneously in reality). Should not produce a loud "pop" when enabled, since each input is not connected directly but has a series resistor (which is mandatory in order not to overload the sources when connected to GND while muting). The output is supposed to be buffered since the series resistors will attenuate it significantly if connected directly to a load. I was very surprised that I could not find even a similar circuit online. Most designs only enable mono muting, or assume the two inputs are precisely identical (such as for microphone sources), but not all sources are mono (eg. most AUX sources). This circuit will work with both single and dual supply. To operate with dual supply, just subsitute every GND with the VirtualGND of your design; the operational aspect will be exactly identical.

published 6 years ago