to feed the AR Generator and LFO
outputs to the CV inputs of the VCOs.
When on, you will hear the obvious
effect as you advance the LFO and/or
AR Gen output adjustments.
S9 causes Oscillator 2 to sync to
the frequency of Oscillator 1. This
provides some very cool timbres that
you will hear if you turn on Sync and
then tune Oscillator 1 lower than
Oscillator 2 and sweep Oscillator 1
upward in frequency.
NOTE: If you don’t plan to use
the external CV (Control Voltage)
capability of the device, you can
eliminate the following components:
R62 and R63.
■ FIGURE 7. Sound Lab Mini-Synth
Front Panel Wiring.
I highly suggest that you build
the Sound Lab Mini-Synth on a PC
board, but you can wire wrap it,
breadboard it, or plain-old kludge it
if you want to. Building the Sound
Lab into an unusual case — perhaps
involving some Plexiglas — can be
an interesting project, but the front
panel should be conductive (
aluminum or steel). You can see the PC
board layout and Parts legend for
the Sound Lab Mini-Synth on the
Nuts & Volts website ( www.nuts
I can’t stress enough how smart it
is to use IC sockets. De-soldering ICs
is never any fun and, as a matter of
fact, it’s a royal pain. If you ever have
to de-solder an IC, here is the correct
method: First, cut all of the legs so
that the body of the IC comes away
from the board. Then, de-solder and
remove each leg individually (unless
you have one of those cool chip
de-soldering tips for your soldering
iron). Doing it this way — though
tedious — will lessen the chance of
PC board damage.
Once you decide on a case, drill
all of the holes to accommodate the
switches and pots that you bought.
Figure 6 shows a useful layout, but
feel free to be creative. Mount all
of the switches and pots and then
tighten the mounting nuts for every-
Mount a couple of terminal strips and solder the junctions
of the wires and the resistors to them for support. Be careful
not to short the resistor leads to the pot bodies.
Triple-check your wiring!
Ground +9V -9V
To Battery Connectors
Panel Wiring Diagram
R88 & C13