Inverting Mixer

Most signal mixers make an effort to keep the same polarity of a signal as it passes through the mixer. However, some mixers may invert the polarity or “phase” of a signal (as it’s a simpler design); other mixers may allow you to invert a signal on purpose so that you can experiment with tricks like adding one waveform or filter mode output out of phase with another coming from the same oscillator or filter.