[sdiy] anyone have some creative mods/addons for a 303? Devilfish style?

[Danjel van Tijn]

HI,

A group at MIT reverse enegineered a Roland TB-303 and sourced most of the 
original transitors and components. They also added MIDI and USB 
functionality and some other features. AT it's root is is still a 303, the 
schematic even uses the same designations as the original 303 (e.g. R110 of 
x0xb0x = R110 of TB303).

On the site are a few simple mods such as adding a pot to adjust slide time, 
changing enevelop depths and increasing resonance...all of these are failry 
basic.
I have been interested to add some mods that will really allow me to "mess" 
up sounds. I think the Devilfish Mod for the 303 had some great ideas such 
as using the VCA output to modulate filter cutoff.
How would I implement that? I know I would probably be connecting the VCA 
output via a 100K resistor and then a 0.47uF cap (so that only audio 
frequencies are passed to the filter). Where would I connect it? (I have 
included links to the schematic below). I would also want to use a pot to 
control FM amount.

Also, what are some other cool mods I could do? I was thinking of having the 
VCO output feedback into it's CV input (like operator feedback in FM 
synthesis) so that I could get a noise source. Again I would control that 
feedback with a pot. 

Another idea I had was to put a small ring mod board in there and have an 
external audio input be the modulator or perhaps put a small LFO inside.

Any other ideas? I am new to this so the mroe details the better!


http://web.media.mit.edu/~ladyada/make/x0xb0x/files/mainboard_beta.png

http://web.media.mit.edu/~ladyada/make/x0xb0x/index.html


thanks!


Danjel
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