Four octaves total. When you turn the VCO1 Tune knob, a LED lights up to indicate an octave increment. The knob’s pitch is quantized in semitones.
VCO1’s tuning can be pitch-quantized or respond smoothly when used as a modulation destination. This is set by pressing and holding Settings then moving the VCO1 Tune knob, and saved per Preset. The options are:
Not in this menu. But Bend Range can be Morphed, so you could create a Preset where, for example, the A value is a semitone but the B value is an octave. This is most easily achieved in the PolyBrute Connect editor software, like so:
The VCOs are designed to combine the warmth of vintage synths with the stability of modern ones, but real analog circuits can require occasional calibration. Fortunately, the PolyBrute has a routine for this.
Press Settings > 8 (Misc) > 4 (Voice Auto-Tuning) to bring up this menu:
From there, you can choose 1 to calibrate the VCOs or 2 for the VCFs (this calibrates the cutoff and resonance ranges of both filters). The process takes a few minutes and the PolyBrute will not be playable during this time.
It’s also a good idea to give the PolyBrute about five minutes after powering on to warm up and fully stabilize, especially at cooler room temperatures.