[LAD] [IDEA] Amp and effects modeling software for guitar

[Darren Landrum]

almbfsek at turk.net wrote:
> Few days ago I came up with an idea about an open source guitar
> modeling software. But because of my lack of knowledge on both
> electronics and audio engineering I couldn't decide if it worths
> something. Here it is directly quoted from linuxmusicians.com
> tinfo/linux-audio-dev 

... snipped for brevity...

I've been researching putting together my own guitar amp sim (among many 
other things). Of course, this is amongst many other things, as my mind 
tends to scatter while working on several projects simultaneously and 
incrementally, but that's a whole other issue.

I've found a few papers here and there on wave digital filters (WDFs) 
and "lumped modeling", which appears to be the closest you can get to 
modeling circuits (including non-linear behavior) right in a computer 
and have it be reasonably efficient, too. These techniques are also used 
for modeling physical systems within a computer (piano hammers are a 
common example).

I was going to try to create a WDF library for Faust (a functional DSP 
programming language that compiles to efficient C++) so I could play 
around with a few ideas. I can't guarantee when I'll be done, though, as 
I have a malfunctioning sound card that I can't replace for a while.

Here's a link to a paper about modeling a guitar amp using WDFs:
http://lib.tkk.fi/Diss/2008/isbn9789512292431/article4.pdf

And here are some sound file examples:
http://www.acoustics.hut.fi/publications/papers/icassp-wdftube/

As for how to implement WDFs and connect them together, I'm still trying 
to figure that out myself. The definitive paper on the subject costs $30 
from AES.

If you'd like to compare notes and ideas, please feel free to contact me 
off-list.

-- Darren