[PD] Csound opcode Moogladder to Pd?

[Frank Barknecht]

Hallo,
Martin Peach hat gesagt: // Martin Peach wrote:

> Anton H?rnquist wrote:
> 
> >I've used the Csound opcode Moogladder (based on an algorithm by Antti
> >Huovilainen) in Pd using csoundapi~. It uses a lot of cpu cycles but
> >it sounds really good. The csoundapi~ external is useful but it only
> >allows one instance per patch on windows so ideally I would like to
> >have this opcode as a Pd abstraction or external and get rid of the
> >csoundapi~ external.
> >
> >Is it possible to convert the Moogladder opcode to a Pd abstraction?
> >
> >Csound code: http://www.csounds.com/udo/displayOpcode.php?opcode_id=32
> >
> 
> It should be possible to make an external with that. I could give it a go, 
> but there's already an extern [moog~] in ggee of the pd-extended. Is that 
> not the same?

I think [moog~] follows the older Stilson/J.O.Smith model of the moog
filter from 1996, while the moogladder opcode is an implementation of a
later publication from 2004: http://dafx04.na.infn.it/WebProc/Proc/P_061.pdf

I think, it may also be possible to implement it as a pure Pd
abstraction with some stacked [rpole~]s and fine tuning, as from a quick
look it seems to be just a bunch of first order filters with
tanh()-distorted filter coefficients. But quick looks may be 
deceiving ...

Ciao
-- 
Frank