Oakley OMS-820 User Manual

Oakley Sound SystemsOakley Modular SeriesOMS-820 issue 2The MOTM-820 Companion ModuleBuilder’s GuideV2.2.0Tony Allgood B.EngOakley Sound SystemsCARLIS

ComponentsFor general information regarding where to get parts and suggested part numbers please see our useful Parts Guide at the project webpage or

the same range you should get the same brightness from each one. I have used red, orange, and green, for no particular reason other than to look like

Discrete Semiconductors1N4148 or 1N914 signal diode D1-9BC549 or BC550 NPN transistor Q9, Q5, Q8, Q12, Q11, Q10, Q1BC559 or BC560 PNP transistor Q7,

The Front PanelOn the website I have included a 1:1 FPD database of the suggested 1U front panel layout. Actual panels can be obtained from Schaeffer-

The Schaeffer panel database uses 6.3mm diameter holes which are designed for Cliplite LED lenses available from Maplin in the UK. Other LED lenses ma

ConnectionsThe power socket is 0.156” Molex/MTA 4-way header. Friction lock types are recommended. This system is compatible with MOTM and standard Oa

switch that goes to the bottom pad. The middle pin goes to the middle pad, and the bottom pin goes to the top pad.The next switch is the final toggle

TestingSince there are two sections, we will test each one in turn. The easiest and the best to test first is the LFO function. Simply flip the LFO/EG

Final CommentsIf you have any problems with the module, an excellent source of support is the Oakley Sound Forum at Muffwiggler.com. Paul Darlow and I

2

IntroductionThis is the Project Builder's Guide for the issue 2 OMS-820 module from Oakley Sound. This document contains a basic summary of its o

The envelope generator can be triggered by two means, either a gate input as normal ADSRs, or a push button, GATE, on the front of the OMS-820. When i

synthesiser. The PCB has four mounting holes, one in each corner should you require additional support which you probably won’t.The design requires pl

Circuit DescriptionLet us first refresh ourselves with the operation of the MOTM-820. Basically it is a capacitor that can discharged and charged at a

flips state to its high level. The switcher responds and flies to +15V. This is fed back into pin 3 via R13 and forces it higher still. The op-amp is

pin 10 is passed via R16 to the MOTM-820’s input, thus causing the MOTM to start to charge upwards. R16 is chosen to interact with the MOTM’s input im

Each LED is turned on and off by PNP transistors. When the transistor is off, the LED has current going through it and is on. When the transistor is o