A lot of people get into modular synths because they prefer analog synthesis, so quite often users ask what analog VCO should they consider adding to their system. A very nice option is the Intellijel Dixie II+: it’s small (8hp), has excellent tracking including a 8-position octave switch, supports linear and exponential FM as well as PWM and hard sync, and has six different waveforms including sine, triangle, zig-zag (triangle meets square), sawtooth, square/pulse, and a sub-octave square, all on individual jacks. Sonically, it’s very bright and sharp, meaning it has a lot of harmonics present to play with (except for the sine, of course – indeed, it’s one of the cleanest analog sine waves I’ve measured).
In the movie below, I demonstrate creating a hard sync patch where the master is the single VCO that may be in a small core system or a semi-modular synth like the Moog Mother-32, and use that to drive a second oscillator such as the Dixie II+. For those who wonder exactly what’s going on when you use sync, I focus heavily on what’s happening with the waveform output. I also look at the Dixie II+’s unique Flip function, where the waveform reverses rather than resets when it received a sync pulse from its master, resulting in a new waveform with twice the overall cycle length of the master. This creates a sub-octave sort of feel compared to normal sync:
This is one of four movies on the Intellijel Dixie II+ that is in my course Learning Modular Synthesis: Eurorack Expansion. The first one covers basic operation plus takes a listen to each of its waveforms; the second is the movie above; the third covers patching what I call “static” FM where the modulation ratio (pitch of the modulating oscillator relative to the carrier) and index (depth of modulation) are left untouched – the way to get good, tonal tracking with exponential FM, and the fourth covers dynamic FM where we play with the modulation pitch and depth.