The first time I ever saw a
Negistor was at Christian's old,
original web site
(schematic).
Then, I heard
tell that Zachary Vex had brought up this Negistor idea on Aron's DIY Stompbox
Forum some time ago. Now, apparently ZV is using them in his micro-amp,
little head, thing. To be honest, the theory is a bit over my head, but if you
are curious and yearning for more than I can give you, you might give KeelyNet a
try.
NOTE:
Others who have experimented with the following have
had mixed results. The only advise I can offer to those
who choose to experiment with it and wind up having
difficulty getting the thing to make any noise is to
maybe try using a higher supply voltage like 18VDC instead
of 9VDC.
All I did with this is put
three Negistors in series and tweak some of the component values a little.
Initially, I had some simple switching to select between several different
coupling capacitors. I found that switching the coupling capacitors between the
second and third oscillators sounded a lot more interesting than between the
first and second oscilators. I also found that doing things like jumping a cap
in the first coupling stage to one in the second coupling stage, and connecting
some of these coupling caps to ground (among other things) also made for new
interesting noises. Tri-Negistor Schematic Tri-Negistor PCB Layout Tri-Negistor Wiring Diagram Tri-Negistor PCB Transfer
Every part of this circuit
can be tweaked or changed in some way for different effects. If you decide to
build one, I'd recommend trying some different component values and
wiring/switching schemes on a breadboard until you get something that you like.
On mine, I have a frequency knob for each of the three oscillators, some
momentary push-buttons, and some 3-position (on-off-on) toggle switches. Ended
up with a number of 'do nothing' settings, but that's cool. It'll make a whole
lot of wild freaky noises, too. Try some different stuff and make it your
own.
I did not include an input
for external audio in this build, although it is possible to feed audio into the
base of the first transistor (or maybe somewhere else, like the second or third
one, through a 10pF cap, or something). Anyway, so all the audio clips, above,
are just my Tri-Negistor spazzing out on it's own.






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