The Q155 provides a collection of four useful and experimental processing functions to manipulate control voltages and audio, all packaged in a single-wide module.
The Curver section bends signals into new shapes providing new modulation possibilities and changes harmonics in audio waveforms. Curve a triangle wave into a smooth sine or a peaky wave with high-frequency harmonics. Convert standard envelope attacks into a linear shape and bend pitch voltages into obscurity. Signal curving can be performed manually with the knob or via control voltage. The control voltage input has a built-in inverting attenuator.
The Inverter section provides control of a signal's polarity via voltage control. This works with audio and control to mangle sounds and sequences in surprising and unexpected ways.
The Slope Detector section produces a digital output indicating the slope of a waveform. When the waveform is rising the output is positive, when falling the output is zero. What you do with that output is up to you - control a filter, trigger one envelope from another, control LFO modulation, etc.
The bottom section of the Q155 is a simple and useful VCA to control the amplitude of a signal under voltage control. When CV=0 volts the output is off, when CV=5 volts the output is full on. Like patch cables, you can never have enough VCAs.