Red Rock Sound Ivoks, designed in the style of the 1980s Soviet synthesizer.
On the centre panel is located two audio-frequency oscillators. OSC1 offers frequency band regulator(9), five waveforms (10), and controls for LFO modulation level(11) plus Osc 2 cross-modulation(12). OSC2 offers the same frequency band(13) and waveforms(14), an independent control for modulation depth(15), plus Detuning(16). Underneath these located the mixer, which offers level controls for the two oscillators(17)(18), the noise generator(19), and for audio injected into the external signal input(20).
To the right of these, located the filter block. The top half is a standard ADSR(21)(23)(24)(25) envelope — until you flip the switch "ADSR mode"(22), when it becomes a repeating AD envelope instead. The four controls at the bottom adjust cutoff(26), resonance(27), LPF to BPF(28) switch, LFO level(29) and envelope level(30).
Next after the filter is the VCA block, it also has ADSR(31)(32)(33)(34) envelope along with another LFO level(36) and velocity sensitive(37) control. Again, the envelope can be switched to a repeating mode(35) that generates a triangular waveform determined by the Attack and Decay settings, providing some of the instrument’s most distinctive effects.
The leftmost panels house the LFO controls (top), mode(2) which offers four waveforms, including noise, and a stepped function for sample & hold effects, well as speed(1) control. And global settings such as the master tune(4), master volume(7), legato mode(5), monophonic and duophonic operation(6) and unison(8) switches, and the glide(3) control.