Use the mod wheel to darken the sound (mapped to filter with negative amount). Apply aftertouch for vibrato -- pressure activates LFO 1 routed to pitch. Play with varying velocity: harder playing opens the filter more (Filter Velocity = 35). This lead cuts through any mix.

Hard sync forces Osc 1 to restart every time Osc 2 resets, creating complex harmonics at a locked pitch. Osc 1 is set above Osc 2 (C2 vs C0) to produce the timbral complexity. ENV 3 sweeps Osc 1's frequency (O1F) with a slow decay (87) for a pronounced attack sweep -- this is the classic Prophet-5 sync sound. The mod wheel darkens the sound by closing the filter (negative amount), and aftertouch adds vibrato by controlling LFO 1 amount routed to all oscillator frequencies.