Using a dotcom (MU) power connector with Oakley 5U modules

[Synthbuilder]

If you are using the five way Synthesizers.com power header on any Oakley 5U module then you need to fit the MU power header into the PWR location on the PCB. Except in special circumstances (see below) you will also need to link pins 2 and 3 of the location marked PSU on the PCB. Therefore you need to solder a small wire link between the middle two pins of PSU. This joins module ground (or local 0V) with panel ground (panel 0V).

The MOTM/Oakley header PSU has two 0V connections which in any MOTM/Oakley build will, on the fitting of the power connector to the board, automatically connect pins 2 and 3 together via the modular's distribution board. This does not normally happen when you use the MU power connector which is why you need to use an additional wire loop to join the middle solder pads on the module's main board.

On many newer issues of my 5U modules an alternative form of MU power is offered. This uses the normally unused pin 5 of the Synthesizers.com MU power header as a connection only to panel 0V. As with pin 3 on the MOTM connector, pin 5 of PWR connects only to the sockets' sleeve connections and to the front panel metalwork via the sockets' mounting bush. Ordinary MU power harnesses and distribution boards do not have a connection to pin 5 so the modules being used with such harnesses or distribution boards must have pads 2 and 3 of the PSU header location linked on the board. If, however, you are using an issue 2 MU Dizzy board to distribute your power and have made a non standard five way connector to connect your module to the MU Dizzy, then you do not need to fit the wire link connecting pins 2 and 3 of PSU on the board. This additional 0V connection doubles the amount of ground wires to your module and may reduce the chance of intermodule crosstalk and other problems. All Oakley boards that have this capability state so in the PSU section of the Connections part of the builder's guide.

Tony