Both envelope generators are identical and provide control voltages that can be used for dynamic change of all voltage controlled parameters, such as; frequency, amplitude, pulse width, cutoff.
The most common use is controlling a filters cutoff frequency and a voltage controlled amplifiers amplitude in order to achieve dynamic timbre- and level-changes. All parameters such as attack time, decay time, sustain level, release time and output level are voltage controlled.
RES-4, four band voltage controlled parametric resonator
The RES-4 is a four band pass filters in to two outputs; BAND PASS and NOTCH. The BAND PASS is a sum of all four filters (RES1, RES2, RES3 and RES4) in phase and the NOTCH is a sum of filter1 (RES1) + fiter3 (RES3) in phase and filter2 (RES2) + (filter4 (RES4) inverted. The result of these two outputs is a different frequency response with differently positioned notches for the BAND PASS and the NOTCH.
All parameters (Peak frequency, Bandwidth and Level) can be controlled manually (knobs) or by CV inputs, individually for all four resonators. Additionally, peak frequencies and levels, for all four resonators, can be controlled by linked CV inputs (MASTER CV FREQ and LEVEL)
The RES-4 has two switchable modes: bandpass and notch and it even has a bypass switch.