Free The Tone PHV-1 PHASE INVERTERThe Free The Tone PHV 1 is a device which inverts the signal phase of an effects unit or amplifier. It inverts the input signals phase from in phase to out of phase or out of phase to in phase. It is very important to create an environment in which you can manipulate the signal phase. By controlling whether a signal is in phase or out of phase, your sound making palette becomes richer and broader. For example, many wah wah pedals, compressors,