[LAD] simulating analog audio devices

Erik de Castro Lopo mle+la at mega-nerd.com
Fri Jun 1 00:34:46 UTC 2007

Robin Gareus wrote:

> hey LADs.
> For those of you who have not followed the 'fuzztone' thread on LAU. I'd
> like to announce a /cool hack/ to ngSpice that provides soundfile I/O
> capabilities. - it's more a LAD than a LAU issue anyway.

This is a CoolAsAllFsck (tm) hack as far as I am concerned.

> Simple tests sound rather promising; but my fuzztone experiment is not
> really satisfying yet. well, maybe it's just meant to sound *that* weird
> ;)

I used Spice as part of my engineering degree and also in jobs 
later, but my memory of this is definitely hazy.

However, my memories of how spice works is my discretizing the
differential equations that describe the components. I believe
the specification of the time step determines how fine grained
(in time) a grid will be used for operating on the diff 

One thing you might have missed is matching up the samplerate of
the input file with the time grid of the spice calculations. 
You alos want to be *really* careful about how you interpolate
the file data to spice sample rate. Please, please, please, do
not use linear interpolation. Secret Rabbit Code is probably 
the way to go here.

Erik de Castro Lopo
Of the four project development variables - scope, cost, time and
quality - quality isn't really a free variable.  The only possible
values are "excellent" and "insanely excellent", depending on
whether lives are at stake." -- Kent Beck, XP Explained

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