STKFMVoices — STKFMVoices is a singing FM synthesis instrument.


STKFMVoices is a singing FM synthesis instrument. It has 3 carriers and a common modulator, also referred to as algorithm 6 of the TX81Z.


asignal STKFMVoices ifrequency, iamplitude, [kc1, kv1[, kc2, kv2[, kc3, kv3[, kc4, kv4[, kc5, kv5]]]]]


ifrequency -- Frequency of note played, in Hertz.

iamplitude -- Amplitude of note played (range 0-1).


kc1, kv1, kc2, kv2, kc3, kv3, kc4, kv4, kc5, kv5, kc6, kv6, kc7, kv7, kc8, kv8 -- Up to 8 optional k-rate controller pairs for the STK opcodes. Each controller pair consists of a controller number (kc) followed by a controller value (kv). The 5 controller numbers and values that work for STKFMVoices are:

  • kc, kv -- 2, vowel.

  • kc, kv -- 4, spectral tilt.

  • kc, kv -- 11, speed of low-frequency oscillator.

  • kc, kv -- 1, depth of low-frequency oscillator.

  • kc, kv -- 128, ADSR 2 and 4 Target.

[Note] Note

The code for this opcode is taken directly from the FMVoices class in the Synthesis Toolkit in C++ by Perry R. Cook and Gary P. Scavone. More on the STK classes can be found here:


Here is an example of the STKFMVoices opcode. It uses the file STKFMVoices.csd.

Example 746. Example of the STKFMVoices opcode.

; Select audio/midi flags here according to platform
-odac     ;;;RT audio out
;-iadc    ;;;uncomment -iadc if RT audio input is needed too
; For Non-realtime ouput leave only the line below:
; -o STKFMVoices.wav -W ;;; for file output any platform

sr = 44100
ksmps = 32
nchnls = 2
0dbfs = 1

instr 1

ifrq	=	p4
kjet	line	p5, p3, p6			;vowel
ktlt	line	p7, p3, p8			;specral tilt

asig	STKFMVoices cpspch(ifrq), 1, 2, kjet, 4, ktlt, 11, 10, 1, 10, 128, 50
asig	=	asig * 4		;amplify
	outs asig, asig


i 1 0 5 5.00 10 120 0 0 
i 1 + 2 8.00 80 82 127 0

See Also



Author: Michael Gogins (after Perry Cook)
Irreducible Productions
New York, NY

New in Csound version 5.11