[sdiy] aaron cram? + cem3394 interface questions

[gregory zifcak]

hi,

has anyone heard from aaron cram? his website hasn't been updated for a 
while. i sent him an email but haven't heard from him.

maybe someone else can help me out.

i would like to refer to his cem 3394 interface 
(http://www.ori.org/~aaronc/synth/CEM3394_V2.pdf) in modularizing my simmons 
sds-800, which uses the 3394. i have a conceptual grasp of basic 
electronics, having modified a bunch of my other gear from schematics and 
instructions, but i don't know much about the math. as the cem has such a 
small acceptable voltage range, i want to be sure i have a handle on the 
risks before i dive in. 3394 datasheet and sds-800 schematics are at 
http://userwww.sfsu.edu/%7Egzifcak/sds-800.html

here are the things i am unsure about:

-does the additional circuitry on the interface make the cem safe for use 
with other modulars (+/-15, etc)? does it somehow scale down larger inputs 
to a +/-5v range? or is this just for use with +/-5v voltages?

-why do some of the inputs need the lm324s, but not others (resonance 
input)? what is that op
amp configuration called? are those buffers? any suggestions for where can i 
learn about them?

-the simmons' internal circuits use 100k pots vs the interface's 10k. how 
does this change things? for instance, the mix pot (ext input/internal osc) 
is 100k, through a 470k resistor, followed by a 220k to ground. to add a cv 
input, should i just run a jack through another 470k resistor in parallel? 
how would these changes affect the cv range? should i remove the 220k to 
ground? any explanation of the principles here would be greatly appreciated.

thanks a lot in advance for any help,
greg