The Z2040 A 24db 4-Pole Voltage Controlled Lowpass Filter, an implementation based on the original US patent of the SSM2040 filter chip used in the Prophet 5 Rev2 synthesizer. The Z2040 also adds a lot of extra features on top of the original 4-pole discrete OTA core allowing extra modulation capability, extended flexibility and control over this deep cut-off low pass filtering core. The Z2040 is capable of producing thick, overdriven grit as well as warm, smooth sweeps.