The analog module 540 of the new System-500 comprises two independent envelope generator units and one low frequency oscillator unit.

The envelope generator provides control of ADSR parameters (attack, decay, sustain, release) - this allows receiving control signals for monitoring various modules (such as VCA, VCF, etc.). Envelope can be triggered by an external or internal signal, as well as manually.

The low frequency oscillator (LFO) has five outputs offering different waveforms, a frequency controller, a frequency range switch, a control input for triggering, a back-off algorithm control.