Purrtronics - Resonant Quadruple Lo-Pass Gate

The RQLPG consists of four lo-pass gates. Despite its classic, optocoupler-based circuit design, the module’s sound is exceptionally hard. Using the RQLPG’s resonance controls, audio signals can be sharpened very nicely. High values make the LPGs self-oscillate. In this state, the circuits may be used to generate psy trance kicks and zap sounds. On top of that, it is also possible to employ the RQLPG as a VCA with up to four channels.

The Resonant Quadruple Lo-Pass Gate features four identical channels. Using switches, you can choose between two modes of operation: LPG and VCA. The circuits are controlled via CV inputs. Additionally, there are offset potentiometers to open each channel manually. Another set of knobs determines the resonance strength while the circuits are in LPG mode. High values lead to self-oscillation. With the help of the CV inputs, the Lo-Pass Gates can then be played as drum voices. Hint: Using additional filters, the resulting kicks and zaps can be shaped very nicely.