[sdiy] Ray Wilson's Sound Lab, first report

[Tim Parkhurst]

 Hmmm, I would have sworn that the Sound Labs VCOs were expo response. The
bit describing the VCO circuit says...

The sound lab uses two voltage controlled ramp oscillators. IC5-B and IC5-A
and associated transistors and components comprise a linear voltage to
logarithmic current convertor. 

Could it just be that its not tracking your other keyboards very well.
Perhaps a v/oct rtimmer could be put in to adjust the tracking, and matching
(and gluing together) the two 2n3904s in the expo converter would help the
tracking and accuracy. Maybe Ray has some other tips.

Tim Servo

-----Original Message-----
From: R. Drake
To: synth-diy at dropmix.xs4all.nl
Sent: 2/22/04 5:57 PM
Subject: [sdiy] Ray Wilson's Sound Lab, first report

All,

Just finished assembling my first Sound Lab Mini-Synth, using the PCB
purchased 
from Ray Wilson.  Info on the project is on his site:
 
www.musicfromouterspace.com/analogsynth/SOUNDLABMINISYNTH/soundlab.html

Basically, it's two VCOs and a white noise source, mixer, LP/BP filter,
and
VCA, with an LFO and Attack/Decay generator as modulation sources.  I
wired
this one up pretty close to Ray's suggested layout, which hardwires the
VCOs->Filter->VCA and has switches to assign the modulators any or all.

The PCB was nicely laid-out, heavy-duty and well-labeled.  It took me an
afternoon to populate 2 boards.  Took me another afternoon to build a
case
and front panel for 1, and then most of a day to wire the panel to the
PCB.
Lots of flying wires, probably the hardest part of the project, I wound
up
w/ 4 separate bundles of wire to try and keep it tidy (w/ only moderate
success).  But it worked on the first try, so I guess my wiring job
wasn't
that bad. 

The end result is a great little knob-twiddler, producing some very nice
individual sounds.  The oscillators are linear, so even tho you can
connect
them to external CVs they won't track (exponential) keyboards.  I'm
planning
on putting the other one together in a patchable layout, and adding a
couple
of joystick controllers, I think this would add a lot of versatility and
make it more "performable".  Ray's been adding some info on a patchable
version to the documentation on the site.

I think this would make a good "stepping stone" project for someone
who's
played w/ some kits, or done some bending.  I'm planning on bringing it
to
the AHMW gathering in March, if anybody's interested in seeing it.

Thanks to Ray for making this project available, as well as all the
other
projects on his site.


regards,
lbd



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