Bill and Will's Synth
Oakley Sound Systems
Analogue Overdrive and Distortion Module


January 2011 -

This month we want to build a couple quick modules - relatively inexpensive ones that will give us some cool sounds - and Gino Wong sent us a couple PCBs he had lying around... the CGS Real Ring Modulator thingy and this, the OMS Analog Overdrive and Distortion Module.

We got our Panels from Bridechamber.

Table of Contents

This page has become really long, so here's a table of contents that we hope will make it easier to traverse:

Background - presents an explanation and Ken Stone's initial description of the Module with his photos

Modifications - presents the minor physical modifications we made to th 3U PVB to use in our 5U implementation

Parts - presents a Bill of Materials and notes about it

Panel - presents the MOTM format panel

PCB Mounting Bracket - presents our design for a PCB mounting bracket - the one we used

Construction Phase 1 - Resistors, Capacitors, IC Sockets, Power Plugs, MTA headers

Construction Phase 2 - Trimmers, Tube, Panel connetcions

Set up / Testing

Use notes


The Oakley Sound Systems Page describes the Module:

"This is a simple but very effective waveform modifier module. It has two basic modes selected by a switch. Hard clipping is a hard edged distortion type effect useful for grunging up your signal. Soft clipping is a more subtle effect and produces a clean sounding overdriven amp sound.

"Three front panel pots control the sound. Gain controls the overall gain of the 'pre-amplifier' stage and essentially determines the level of overdrive or distortion. The Tone control is an effective EQ control that affects the frequency response of the effected output. The Balance pot is essentially a wet/dry mix control that allows you to add only as much of the effect as you want.

"Voltage control is determined not within this unit, but as part of the signal chain placed before this module. Using a VCA to control the signal level that is fed into this unit will determine the strength of the overdrive or distortion. Using a VCF to alter the timbre of the signal fed to this module will control the overall harmonic level far more than using a filter alone. In fact, hard sync type sounds can be easily obtained by simply sweeping the filter's cut-off frequency."

Click here to get to the Oakley EFG page.

Click here to view the User's Manual .pdf file.

This photo from the Oakley site shows the 5U implementation of the module.  It shows the PCB designed especially for it:

But Gino sent us the Eurorack style PCB so our build will be an adaption, drilling holes for mounting screws and mounting the PCBs on a bracket:



So - the 3U PCB has no holes to mount it on a bracket - which we needed to do.  We drilled some.  It looked to us like we could rather easily fit them in these approximate locations:


Will and I have developed a parts-list / bill-of-materials in the form of an XL spreadsheet based on the parts list from Oakley.

In the BOM, the left-most column is the "part."  The parts we've ordered have a green background.  These parts we have a high (but not perfect) level of confidence that we've specified correctly - we caught a mistake or two in part numbers / prices as we were ordering.  please double-check us and let us know of mistakes you find.

Corrections to BOM:

None yet -


None yet -

Click here to download the spreadsheet (apx. 48K). 


We got ours from Bridechamber.

PCB Mounting Bracket

After drilling holes in the PCB, we could modify a bracket to use with it.

Construction Phase 1

All the stuff in Phase 1 gets soldered using "Organic" Solder.  At every break in the action, we wash the board off to get rid of the flux.

Construction Phase 2

All the stuff in Phase 2 gets soldered using "No-Clean" Solder and the PCB doesn't get washed off from here on.

Set up / Testing

Use Notes


Bill and Will's Synth Main Page
Send eMail to Dragonfly Alley

The fine Print:
Use this site at your own risk.
We are self-proclaimed idiots and any use of this site and any materials presented herein should be taken with a grain of Kosher salt. If the info is useful - more's the better.  Bill and Will

2005-2011 all frilling rights reserved