Revelation Cable Co’s stereo summing cable allows you to play music from your phone, iPad or any device that has a 3.5mm output. The stereo signal is summed together creating a mono signal that can be played through a guitar amplifier, mixer or PA system. As well, it can be use on the output of a Teenage Engineering OP-1 to go to effects pedals. While most stereo summing cable just short the Left and Right output conductors, we use resistors to prevent the signals from back-feeding into each other. This prevents there from being distortion or noise issues, as well as preventing damage to your output device.