rezzy

rezzy --  A resonant low-pass filter.

Description

A resonant low-pass filter.

Syntax

ar rezzy asig, xfco, xres [, imode]

Initialization

imode (optional, default=0) -- high-pass or low-pass mode. If zero, rezzy is low-pass. If not zero, rezzy is high-pass. Default value is 0. (New in Csound version 3.50)

Performance

asig -- input signal

xfco -- filter cut-off frequency in Hz. As of version 3.50, may i-,k-, or a-rate.

xres -- amount of resonance. Values of 1 to 100 are typical. Resonance should be one or greater. As of version 3.50, may a-rate, i-rate, or k-rate.

rezzy is a resonant low-pass filter created empirically by Hans Mikelson.

Examples

Here is an example of the rezzy opcode. It uses the files rezzy.orc and rezzy.sco.

Example 1. Example of the rezzy opcode.

/* rezzy.orc */
/* Written by Kevin Conder */
; Initialize the global variables.
sr = 44100
kr = 4410
ksmps = 10
nchnls = 1

; Instrument #1.
instr 1
  ; Use a nice sawtooth waveform.
  asig vco 32000, 220, 1

  ; Vary the filter-cutoff frequency from .2 to 2 KHz.
  kfco line 200, p3, 2000

  ; Set the resonance amount.
  kres init 25

  a1 rezzy asig, kfco, kres

  out a1
endin
/* rezzy.orc */
        
/* rezzy.sco */
/* Written by Kevin Conder */
; Table #1, a sine wave for the vco opcode.
f 1 0 16384 10 1

; Play Instrument #1 for three seconds.
i 1 0 3
e
/* rezzy.sco */
        

See Also

biquad, moogvcf

Credits

Author: Hans Mikelson
October 1998

New in Csound version 3.49