My Make Noise DPO (Dual Prismatic Oscillator) arrived yesterday.
The other Buchla 259 style complex oscillators and related constellation of similar-ish configurations didn’t really prepare me for the experience of using this one.
The word I’ve settled on to describe the DPO is feral. If you approach it slowly and make no sudden moves, it might let you pet it or eat out of your hand. But it might run away or bite you.
To compare: the Hertz Donut mk2 uses linear TZFM and has a convenient tracking mode that has the modulator perfectly follow the primary oscillator, so it can easily remain true to pitch no matter how intense the modulation. The shaper — while it’s a dirty digital “waveform discontinuity” thing — just has one 3-way mode switch and a single intensity level to work with.
The DPO does exponential and/or linear FM in both directions simultaneously if you want; even the linear FM in the traditional modulator-to-primary direction varies the pitch with intensity. There’s a vactrol-based “follow” feature that tries to follow the pitch input — but not the knob, making transposition less easy — but always has at least some slew to it. For perfect tracking one can mult the pitch to two inputs, but the knobs are still independent. (There are two sync modes for the carrier and one “is it even working” subtle super-soft-sync input for the modulator, which don’t really lock things down to steadiness.) The shaper has three different parameters to choose from, which each make radical changes to the sound (and are radically different from each other).
The DPO is made to growl and wobble and get weird. And that’s a good thing; if I want the smooth Hertz Donut style dynamic FM I can do that with the ER-301, or Rings in FM mode.
It’s going to take a while to really learn the DPO in an intuitive sense. But it’s one of the most exciting bits of synth gear I’ve tried in a while.