This control sets the glide time between notes for both VCO1, VCO2 & VCO3 (when used as a third oscillator). Notes will glide from the previous note played.
Sets the glide time difference between notes for VCO2 only. Use this to create portamento offsets between VCO1 and VCO3.
If this knob is at zero (straight up) VCO2 will have the same glide time as VCO 1, which is set by the global knob.