STKStifKarp — STKStifKarp is a plucked stiff string 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:

STKStifKarp is a plucked stiff string instrument. It a simple plucked string algorithm (Karplus Strong) with enhancements, including string stiffness and pluck position controls. The stiffness is modeled with allpass filters.


asignal STKStifKarp ifrequency, iamplitude, [kpos, kv1[, ksus, kv2[, kstretch, kv3]]]


ifrequency -- Frequency of note played, in Hertz.

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


kpos -- controller 4, pickup position. Value range of kv1 is 0-127.

ksus -- controller11, string sustain. Value range of kv2 is 0-127.

kstretch -- controller 1, string stretch. Value range of kv3 is 0-127.

[Note] Note

The code for this opcode is taken directly from the StifKarp 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 STKStifKarp opcode. It uses the file STKStifKarp.csd.

Example 1055. Example of the STKStifKarp 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 STKStifKarp.wav -W ;;; for file output any platform

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

instr 1

ifrq	=	p4
kv1	line	p6, p3, p7				;Pickup Position
kv2	=	p5					;String Sustain

asig	STKStifKarp cpspch(p4), 1, 4, kv1, 11, kv2, 1, 10
	outs asig, asig


i 1 0  2  5.00 0  100 100
i 1 +  40 5.00 127 1  127
i 1 10 32 5.00 127 1  10

See also

STK Opcodes


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

New in Csound version 5.11