Meeblip bassline demo by cdm "Oscillator A & B slightly detuned, square wave on A and sawtooth on B. FM turned all the way up, distortion on. The filter resonance turned way up (hence the chirpy squeal) and the filter cutoff knob is initially open, then twiddled a bit to help the filter chirp. At the end, I just slowly turn the cutoff down. the VCF envelope modulation is mapped to MIDI velocity, which adds some sonic movement." via meeblip on noisepages where you'll find more info. $129 open source hardware box.