How can I modulate the waveform of just one of the oscillators on the Moog One?

In the WAVEFORM MODULATION section of Moog One’s front panel, you can quickly apply modulation from LFO 3 to the wave angle and pulse width of the oscillators. However this will affect all three oscillators on the active synth layer. If you want to modulate the waveform of a single oscillator, you will have to either use the modulation matrix or assign the relevant parameter using the DEST buttons or EXPRESSION ASSIGN for the controller you want to use.

To use the modulation matrix, press the MOD button below the display. Use the first soft knob to select the desired controller, and then rotate the last soft knob to select the oscillator you want it to affect. Once you’ve selected the right SOURCE and DESTINATION, you can press the large encoder knob to change the percentage amount of the SOURCE and which parameter of the oscillator you want to modulate. SAW and TRIANGLE apply the modulation to the wave angle of their respective wave shapes, while PULSE changes the width of the pulse wave. MIX modulates between the pulse wave and the triangle or sawtooth waves. 

These parameters can also be set by selecting the DEST button from a modulation source and then moving the WAVE ANGLE or PULSE WIDTH knob for the desired oscillator.