 Two direct modifiers to the VCOs are a detune control that only affects oscillators 2 and 4, and a Pulse Width control that goes to cancellation either side of 50% phase symmetry of a square wave; pulse width can be routed to MG1, MG2, or voltage-controlled filter (VCF) envelope.There is one independent noise generator with an amplitude control (frequency and shape is modified by the VCF).There is one 24/db octave exponential low-pass VCF with resonance, scaling and invertible envelope control shared across all four VCOs.