Pigtronix Resotron Pitch-Filter Synth
~$120 | Using the same chip as classic synths such as the Prophet 5, it features BP, HP, and
LP filters, envelope up and down modes as well as a unique analog pitch tracking mode that
changes the filter frequency based on the notes you play. Comes with controls for peak, cutoff,
sensitivity, blend, and glide (attack). Oscillate mode turns it into a self-oscillating synth.