Oakley OMS-820 - Manual (Page 3)

Introduction
This is the Project Builder's Guide for the issue 2 OMS-820 module from Oakley Sound.
This document contains a basic summary of its operation, a how it works section, a full parts
list for the components needed to populate the board and some basic testing methods.
For general information regarding where to get parts and suggested part numbers please see
our useful Parts Guide at the project webpage or http://www.oakleysound.com/parts.pdf.
For general information on how to build our modules, including circuit board population,
mounting front panel components and making up board interconnects please see our
Construction Guide at the project webpage or http://www.oakleysound.com/construct.pdf.
The OMS-820
The OMS-820 is a companion module to the MOTM-820 voltage controlled lag processor. It
adds powerful new features to the superb Synthesis Technology module. No component
changes are needed to the MOTM module, and the two modules are connected together by
just one removable connector hidden behind the front panels.
The module is designed to fit into a 1U MOTM style panel. It requires the standard MOTM or
Oakley power supply.
With this module you can make the MOTM-820 into a voltage controlled LFO with variable
waveshape. Or you use it to make a powerful voltage controlled envelope generator, with
manual set and preset modes. You will be amazed by the uses you can find for this module.
1. LFO
When the mode switch is turned to LFO, the output(s) of the MOTM module will oscillate
between +5V and -5V. The rise time of the waveform will be set by the UP control and the fall
time will set by the DOWN control. The frequency will change according to the settings of
both UP and DOWN. You can also change the rise and fall time together with the UP/DOWN
control on the MOTM. You can easily make saw, reverse saw, and triangle type waveforms.
The LIN/LOG pot on the MOTM will alter the shape of the waveform by introducing the
usual non-linearites of the exponential rise and decay.
Top frequency is 1KHz or so, whilst the lowest frequency is so low I got bored waiting for
one cycle.
2. EG mode
When the mode switch is turned to EG (envelope generator), you get a voltage controlled
AD/AR generator and more besides. This section has four sub-modes. These are selected by
two switches: AD/AR and Gated/Resetable.
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