Hey hey, I just released a couple of Csound User Defined Opcodes (UDOs), including a controllable formant filter optimised for use with MIDI, as well as three voice processing modules, a vocoder, a pitch correction plugin and an auto-tune like opcode that sets a new pitch based on a played MIDI note. Additionally there is a frequency inverter, which mirrors frequencies around a supplied centre frequency and the latest addition the Risset filter. This is a multi-bandpass filter, whose frequencies are controlled by a Risset glissando. You can specify the centre frequency, q-value or bandwidth, number of octaves, direction of the glissando and the modulation rate or tempo. http://juliencoder.de/sound Share and enjoy, <3 Jeanette -------- When you need someone, you just turn around and I will be there <3