Keyboard CV

[jorgen.bergfors at idg.se]

Get Barry Klein's book. It will answer all your questions and also has the 
schematics that you need.

/Jorgen





MIME:LMVogue at earthling.net on 98-09-22 07.17.32
To:  synth-diy at mailhost.bpa.nl @ SMTP 
cc:  (bcc: Jorgen Bergfors/IDGSE)
Subject: Keyboard CV 

Warning, newbie approaching...

OK, I've made a few effects, booster and mixer units before, now I plan 
to
start on synths with a very basic, phat analog synth.  I've got 
schematics
for VCOs, VCFs, envelope generators, etc, the problem is (all 
experienced
builders laugh out loud now...):

How the hell do you make a Control Voltage from a keyboard??  I plan to 
use
the basic FatMan VCOs (or some of the alterations I've seen around), if
that comes into the equation.  As I understand it (??) I need to make 
it so
the CV increases(?) as you go up in frequency - is this linear?  If so, 
the
only thing I can think of is to make a series of resistors, but that 
sounds
a bit dodgy ; )
If not, um...?

At the moment I have a spare 1.5octave keyboard assembly lying around 
(was
4octave, but I cut of 2.5octaves to re-wire my Yamaha SHS-10 - yeah, 
laugh
all you want), so the range isn't exactly huge.  The synth I plan to 
make
is just your very basic setup, two VCOs (might make four for extra
phatness?), overlaid with a LFO for modulation / VCF autosweep, through 
the
VCF, add noise, through the envelope genearator, and out - or some
variation of that (same as my dead Korg Poly800, anyway).

Anyone?  I just want something simple, phat, and CHEAP(!!!), with some 
VCF
knobs to tweak, etc.  Probably just square wave, or sqaure and sawtooth.

(oh yeah, I HAVE tried sorting through the archives first, but didn't 
turn
up anything - unless it's hidden somewhere)

cya
LMVogue

_____________________________________________________ 
                 Lee Mulvogue
              LMVogue at earthling.net
            lmulvo10 at chec.scu.edu.au

 http://www.geocities.com/SunsetStrip/Palladium/3297