Subject: Re: [linux-audio-dev] Diode wave shaper (LADSPA plugin)?
From: Alfons Adriaensen (fons.adriaensen_AT_alcatel.be)
Date: Mon Aug 16 2004 - 18:13:07 EEST
On Mon, Aug 16, 2004 at 04:49:47PM +0200, Stanley Jaddoe wrote:
> The 12k resistor is just an example, it would be nice if it would be treated
> as a variable.
The actual value doesn't matter, you'll get almost the same transfer shape
for any reasonable resistor value. Just make the input level variable, that will
determine how much effect you get.
> How can I incorporate the 1N4148 diode characteristics in the final equation?
All normal silicon diodes (and the 1N4148 is a very normal one) have the same
exponential voltage to current relationship. It is the combined effect of this
and the resistor that is approximated by the two formulae I posted earlier.
It's really not worth the trouble to try and emulate this circuit with any
precision. For example, a change in temperature of 9 degrees (Celcius)
will have the same (minimal) effect as halving or doubling the resistor value.
-- FA
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