Quadigy - Quad Envelope
Klavis Quadigy - Quad Envelope 2 Colors
Javelin - Envelope and VCA
WMD Javelin - Envelope and VCA
Quaid Gigaslope - Quad Multimode Modulator
ALM Busy Circuits Quaid Gigaslope - Quad Multimode Modulator
Malekko Heavy Industry Quad Envelope
Quadrax
Pons Asinorum - Quad LFO/Envelope
Envy Machine - Quad Envelope Modulation Monster
Contour (Black)
Intellijel Quadra
Intellijel Quadra Expander
Buchla Model 281t Quad Function Generator
Quantus Ampla - Quad VCA
Tidal Quad - Quad Filter Modulation Box
Doepfer A-143-1 Quad AD-Generator
XAOC Devices Batumi
Aikido - Dynamic VCA Mixer
Intellijel Quad VCA