Oakley MOTM-820, User Manual

Page 1: ...Oakley Sound Systems Oakley Modular Series OMS 820 issue 2 The MOTM 820 Companion Module User s Guide V2 01 Tony Allgood B Eng Oakley Sound Systems CARLISLE CA4 9QR United Kingdom 1...

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Page 3: ...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 E...

Page 4: ...ules need to come apart at anytime The wires from the connectors are simply soldered to special key locations on the MOTM 820 No component changes are required to the MOTM 820 at all Inserting a jack...

Page 5: ...tput The U1 pins 5 6 7 op amp performs two important jobs Firstly it steps down the 15V swings to a more reasonable 7 5 volts This gives us the peak charging voltage for the MOTM 820 s input This is n...

Page 6: ...positive gate arrives Q9 turns on and pulls its collector down to ground or 0V This inverse version of the applied gate signal is sent to two destinations One is another transistor Q12 This is config...

Page 7: ...de which we have talked about already Also monitoring the BUFFERED voltage is a comparator based around U2 When the voltage exceeds 5V or so the comparator s output goes from 0V to 15V With the AD R s...

Page 8: ...pots have the same pin spacing Not a problem of course if you are not fitting them to the board In the UK Farnell CPC and Rapid Electronics sell the Spectrol pots for a reasonable price For the resis...

Page 9: ...reen for no particular reason other than to look like a traffic light There are five switches on this board The GATE and RESET switches are push switches These are sometimes designated SPNO single pol...

Page 10: ...m orange yellow LED R LD RESET LED 5mm green LED G LD GATE Integrated Circuits 4001 CMOS quad NOR gate U4 TL071 single FET op amp U2 TL072 dual FET op amp U3 U1 Other 4 way 0 156 Molex MTA connector P...

Page 11: ...metimes people like to substitute parts in place of my own recommendations Feel free to do this but remember that there is normally a good reason why I have selected that particular part If you do fin...

Page 12: ...lone Now solder the middle pin first then the other two once the middle one has cooled solid Sometimes transistors come with the middle leg preformed away from the other two This is all right the part...

Page 13: ...f Fit only one nut at this stage to hold the pot to the pot bracket Make sure the pot sits more or less centrally in the pot bracket with legs pointing downwards Tighten the nut up carefully being car...

Page 14: ...t matter which lead goes into which hole of the LED pad if you have used bipolar LEDs since these can go in any way The bicolour LED may go in any way around but I normally try to make sure that posi...

Page 15: ...onnected at the PCB end Use a bit of heatshrink tube to keep the end from fraying The GATE socket s signal lug goes to the pad marked GATE And the RESET socket s signal lug goes to the pad marked RESE...

Page 16: ...try again I like to use as many different colour wires as possible It makes wiring easier and looks great Each wire now needs to be soldered onto key points on the MOTM 820 PCB or sockets Trim back th...

Page 17: ...nd GATED mode Set the UP DN pot to level 7 Now press the GATE button and keep your finger there Does the GATE and SET LEDs light up immediately Does the OUT LED quickly rise in brightness Now let go o...

Page 18: ...d and fixed within one hour The minimum charge is 20GBP plus return postage costs Your comments and questions are important to both Oakley Sound and Oakley Modular In the first instance please use the...