Model 311C
TM
Quick-Start Guide
Each side of the 311C contains the following:
• Quadrature LFO with sine and cosine
outputs and frequency control pot
(range adjustable from several minutes
cycle to low audio). LFO frequency can
be voltage controlled via header on
back of board (accessable from the
end of the unit), but please note that
even though they will work in the audio
range, these are not intended to be 1V/
Octave oscillators, and may not track a
keyboard.
As this LFO takes multiple cycles to stabilise after power on, at
very low frequencies, and this could take quite a while, there
is a “kick-start” circuit built in which will raise the frequency
temporarily when powered on so that panel settings can be left in
place. Do not be alarmed if the frequency is higher at startup. It will
revert to normal in a few seconds.
• Multi-mode gate with five modes. Three are available at a time;
mode sets can be changed by installing or removing a jumper on
each side. (DIY tip: an external switch coud be wired to these pins
for easy access.)
This gate circuit will make a 10V gate signal out of any CV that is
patched into its input.
• Grant Richter’s original JAG (Joystick Axis Generator) with
unipolar/bipolar switch. (It is important to put the switch in the cor-
rect position for the input signal, eg. when running the JAG from a
bipolar signal, switch to +/- 5 V position, and vice-versa.
The JAG takes two (X and Y) input voltages and maps them to 10
different outputs. Using the Sine/Cosine LFO to control the JAG
allows circular modulation. Using two different frequency LFOs to
control X and Y will create Lissajous modulation.
• Two-mode buffered joystick (joystick outputs will be either bipolar
or unipolar, according to position of JAG polarity switch). This
means that the joystick can be used to control the JAG in both
modes. (Joystick is normalled to JAG inputs, but the raw joystick
outputs can be used simultaneously.)
• Illuminated gate button (shows status when active).
Adjustment Trimmers:
Several side-adjust trimmers are located along the edges of the lower
PCB and are accessable for user adjustment by removing the back
of the unit, if desired. It is recommended to leave these set to factory
settings in most cases, but documentation is provided below for
advanced users:
Dome Height 1/2: Attenuates the Dome signal.
LFO Level 1/2: Sets the LFO level. This is adjusted to an optimum
voltage for JAG operation (about +/- 6V), but can be adjusted to user
preference.
LFO Freq 1/2: Sets the frequency offset for the LFOs. Allows some
customisation of the LFO range available on the front panel control.
Please avoid changing the trimmer labelled “Ref” as this sets an
internal 5V reference voltage.
© 2013-2021 Wessex Analogue. All rights reserved. This version of the quick-start guide applies to the current version of the 311C. Older models may be slightly different — please enquire if you have any questions. http://www.wiard.com
