moogladder — Moog ladder lowpass filter.


Moogladder is an new digital implementation of the Moog ladder filter based on the work of Antti Huovilainen, described in the paper "Non-Linear Digital Implementation of the Moog Ladder Filter" (Proceedings of DaFX04, Univ of Napoli). This implementation is probably a more accurate digital representation of the original analogue filter.


asig moogladder ain, kcf, kres[, istor]


istor --initial disposition of internal data space. Since filtering incorporates a feedback loop of previous output, the initial status of the storage space used is significant. A zero value will clear the space; a non-zero value will allow previous information to remain. The default value is 0.


asig -- input signal.

kcf -- filter cutoff frequency

kres -- resonance, generally < 1, but not limited to it. Higher than 1 resonance values might cause aliasing, analogue synths generally allow resonances to be above 1.


Example 266. Example

kfe         expseg 500, p3*0.9, 1800, p3*0.1, 3000
kenv        linen  10000, 0.05, p3, 0.05
asig        buzz   kenv, 100, sr/(200), 1
afil        moogladder  asig, kfe, 1
            out afil 


Author: Victor Lazzarini;
January 2005

New plugin in version 5

January 2005.