When a note is triggered, OSC 1 and OSC 2 start playing. But their waveforms loop differently in time. By Syncing OSC 2 as a slave to OSC 1, OSC2's waveform will be synchronized to OSC1.

The oscillators are 2 different macro's, both with only one audio out terminal. Adding an extra "out terminal" in OSC 1 and an extra "input terminal" in OSC 2, we can get the sync connected. The problem is we don't have S inputs in the OSC 2 Macro. Fix this by replacing the standard oscillators by the Syncs in (Module > Oscillators). Fun, isn't it? Right.. because in *the analog world* you would have a bunch of wires in your hand without knowing you're destroying one that got under your chair.

We will also need a switch to enable or disable the Sync (Module > Panel > Switch). Give it the name Sync.

Now just connect the "Out" of OSC1 to the Sync(switch) "in", and the Sync's output to the "S" input of OSC2. Done.