Orange ON/OFF button to activate effects. Effect selected via 3-position switch to oscillator sync (SYNC), sync and cross-modulation (S & X), or cross-modulation (X-MOD). Effect modulation source assigned via 2-position switch to either filter envelope (VCF EG) or LFO1 (MG1). 2-position switch selects either SINGLE or DOUBLE. When switched to SINGLE (using oscillator sync, for example), oscillators 2, 3, and 4 are synced to oscillator 1. When switched to DOUBLE, oscillator 2 is synced to oscillator 1, and oscillator 4 is synced to oscillator 3. Two knobs, X-MOD and FREQ MOD, control the intensity of each effect.