This refers to a specialized circuit that is sometimes also called a sub-octave divider. It produces a signal in which all output frequencies are effectively half the frequency of the input signal. For example, a 60-cycle input waveform would result in an output of 30Hz. One example of a device capable of producing a sub-octave is the Electro-Harmonix Micro POG Octave Generator Pedal, which is also capable of producing a second output signal that is one octave up from the original frequency.

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