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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

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