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

[harrybissell]

as a rule... one 2SC1583 is better than two (2N3904s)

If it will fit, I'd use these trannies in expo converters instead of
selecting and gluing 2N3904s together.  They have performance
'almost' equal to the high-priced $pread (like the MAT-02 etc)

H^) harry

Tim Parkhurst wrote:

>  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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