[linux-audio-dev] Diode wave shaper (LADSPA plugin)?

[Erik de Castro Lopo]

On Mon, 16 Aug 2004 10:54:04 +0200
Stanley Jaddoe <linux-audio-dev at terabytemusic.cjb.net> wrote:

> Hi,
> 
> I'm trying to convert an existing analog (hardware) synth to an open source 
> softsynth.
> One of the components of the analog synth is a diode wave shaper. The 
> schematic is included (diode.jpg). The Inputs 2, 3, ... n and its resistors 
> are optional.
> 
> I'd like to know if there's a LADSPA plugin 

Possibly, but I'm not too familiar with what is available in LADSPA.

> (or even better: a DSP IIR recurrence relation) 

Nope, not possible with a linear recurrence relationship.

> which emulates the included schematic as close as 
> possible. Unfortunately, I don't have the EE background required to do this 
> myself.

Its actually rather simple (first year EE):

    static inline double
    diode_clip (double input, double clip_level /* should be positive */)
    {   if (input > clip_level)
            return clip_level ;
        if (input < -clip_level)
            return clip_level ;
        return input ;
    }


Erik
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