Pure Data externals (Mac Intel, Linux, Windows).

fumio~: digital model of the Korg MS20 filter, derived from Miller Puckette ~bob (4th order Runge-Kutta)

ota~: digital model of a classic 4-pole OTA filter,  derived from Miller Puckette ~bob (4th order Runge-Kutta)

ring64~: 64-band zero-delay feedback filterbank

zdsv~: zero-delay feedback state variable filter