Mixer

Five sources feed the filter:

• Osc 1 at its Level knob (mixer column on the Osc 1 panel).
• Osc 2 at its Level knob (mixer column on the Osc 2 panel).
• Sub — a square wave one octave below Osc 1, useful for adding low-end weight without retuning the main oscillators.
• Noise — white or pink, selected by the Noise Colour toggle.

All four sources sum into a single stereo mix before the high-pass and ladder filter.

Sub-oscillator

The sub is a square wave one octave below the carrier oscillator. By default that’s Osc 1; under Cross-Mod Type = Sync the sub follows Osc 2 instead (since Osc 1 is then a sync slave of Osc 2). Otherwise the sub tracks Osc 1’s tuning, including pitch modulation, and is band-limited.

A common move: pull Osc 1 Level to ~0.5, raise Sub Level to ~0.7 for a fat bass that retains its top-octave brightness from Osc 2.

Noise

Noise Colour:

• White — uniform spectral density.
• Pink — −3 dB/oct rolloff (1/f). Friendlier on the ladder filter at high resonance.

A small amount of noise (level ~0.1) blended with the oscillators gives a perceptual “lift” — the analog impression of subtle hiss in the signal path. Larger amounts move into wind and percussion territory; use the modulation envelope to gate noise bursts for snare-like attacks.

Parameters

Osc 1 Level and Osc 2 Level are documented on the Oscillators page.