[sdiy] Analog Computational Unit

[Shokwave]

----- Original Message ----- 
From: Ryan Williams

>I thought this might make an interesting module but I'm not quite sure how
to go about using it for audio.  I wonder if anyone has thought of building
something similar? >After looking around I found the MOTM wavewarper which
seems to do exactly this. I wonder if it uses the same chip.

>this IC costs about $35 but I figure if it sounds cool then it'd be worth
it.

Ouch! There's gotta be a cheaper alternative.

I *have* been thinking about something along those lines; I was reading the
appnote for a chip (forget which one right now, it was something fairly
common) that did x*x/y (fudged with other values) etc. I know that this sort
of thing can make some excellent DSP waveshaping algorithms...I was thinking
of deriving squared signal values with it, but was unsure how the squaring
would work. In DSP stuff, I use signals between -1.0 and +1.0; preserve the
sign, and the squared signal never clips. If I squash the signal down to a
max of +-1V, square, then scale back up, will this approach still work? I am
suspicious of this; it can't be that simple.

-Darren