STKTubeBell — STKTubeBell is a tubular bell (orchestral chime) FM synthesis instrument.


Plugin opcode in stkopd. This opcode is part of the plugin repository and has to be installed separately. The plugin repository can be found here:

STKTubeBell is a tubular bell (orchestral chime) FM synthesis instrument. It uses two simple FM Pairs summed together, also referred to as algorithm 5 of the TX81Z.


asignal STKTubeBell ifrequency, iamplitude, [kmod, kv1[, kcross, kv2[, klfo, kv3[, klfodepth, kv4[, kadsr, kv5]]]]]


ifrequency -- Frequency of note played, in Hertz.

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


kmod -- controller 2, modulator index 1. Value range of kv1 is 0-127.

kcross -- controller 4, crossfade of outputs. Value range of kv2 is 0-127.

klfo -- controller 11, speed of low-frequency oscillator. Value range of kv3 is 0-127.

klfodepth -- controller 1, depth of low-frequency oscillator. Value range of kv4 is 0-127.

kadsr -- controller 128, ADSR 2 and 4 target. Value range of kv5 is 0-127.

[Note] Note

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

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). Both the controller numbers and the controller values are krate variables. However, during a performance, normally the controller numbers stay fixed while the corresponding controller values may change at any time. The order of the controller pair is arbitrary, as long as they are after iamplitude. Also, it is not needed that all controller pairs are used.


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

Example 1056. Example of the STKTubeBell opcode.

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

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

instr 1

ifrq	=	p4
kv2	line	p6, p3, p7				;Crossfade of Outputs
kv1	=	p5					;(FM) Modulator Index One

asig	STKTubeBell cpspch(p4), 1, 2, kv1, 4, kv2, 11, 10, 1, 70, 128,50
	outs asig, asig


i 1 0 2 7.05   0 100 100
i 1 + 4 9.00  127 127 30
i 1 + 1 10.00 127 12 30
i 1 + 3 6.08 127 1 100

See also

STK Opcodes


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

New in Csound version 5.11