Oakley midiDAC User Manual - page 18
Connections
How you connect your midiDAC very much depends on where you are going to use the
midiDAC. You may already have an idea of how you are going to connect your midiDAC to
your chosen system. For those building the standard Oakley midiDAC modular panel I will
give the wiring instructions in detail.
The suggested layout uses eight sockets, and wiring them up is straightforward enough. Use
multistrand hook up wire to connect each socket’s signal lug to the relevant pad on the PCB.
Keep your wires short but not too short and use as many different colour wires as you can.
There is no need to use screened cable for such short runs.
If you have used Switchcraft 112 sockets you will see that they have three connections. One is
the earth lug or ground tag. The second is the signal tag which will be connected to the tip of
the jack plug when it is inserted. The third tag is the normalised tag, or NC (normally closed)
lug. The NC lug is internally connected to the signal tag when a jack is not connected. This
connection is automatically broken when you insert a jack. The midiDAC uses only the signal
lugs on each connector. The other two lugs are not used at all in the suggested layout.
The PCB has been laid out to accommodate 0.1” headers for all interconnects. This is very
useful for taking the board in and out for servicing. However, for a panel fitting into a modular
synth, there is no reason why you can’t solder wires directly into the holes.
Socket name
Header
Pin
Pitch
CN1
1
Velocity
CN1
2
Bender
CN2
4
Modulation
CN2
2
Aftertouch
CN2
1
CC
CN2
3
Gate
CN1
3
Slide
CN1
4
The earth lugs of each socket are left floating as a solid ground to the module is already
provided in the form of the power supply ground lead(s). This means that no earth loops will
occur because of inserted patch leads. However, depending on your own system, it may be
necessary to connect each output jack’s ground tag to the AGND on the input power
connector on the PCB. You can connect all the ground lugs together with a piece of
uninsulated wire, and have one piece of insulated wire going back to the AGND pin. But
remember a modular panel will probably be metal, and may well be earthed through the panel
housing. Your best bet is to leave the lugs unconnected at first, and only connect them to
ground if you get problems. My ready made units have the grounding lugs unconnected.
All other Oakley modules have two grounds, one for the chassis and jack screening, the other
for the power supply to the module. The midiDAC couldn’t use this method with just a four
way plug. Here, we have AGND and DGND, both must go back to the power supply
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