Connecting 2 psu's to one power transformer secondary

[JW]

So, let's say you have two boards with a psu on each. In this case, the mnats 1176 rev D's.
The power transformer in this case has a center tap that connects to the boards' circuit ground. With two boards, would I connect this center tap first to chassis where AC ground connects, and then run home run grounds from each individual board's circuit ground to this point? Or should I connect the power transformer secondary's center tap to one board, daisy chain it to the other and then to chassis ground?

And, is it fine to connect the AC power secondaries to the two boards (in series) making sure to keep the same phase?

 

[Matador]

Schematic of what you're trying to do?

 

[CJ]

I would run a wire from each 1176 to a gnd that includes the CT and the filter caps.

 

[RoadrunnerOZ]

Connecting every ground to a single point star ground is the first step - this including the transformer CT.
Second is to keep the AC wiring for the second board away from the first using twisted wires to carry the AC.
Third is to not connect any shield connections from XLR input and output connectors to the audio boards and only shield connect to the chassis at the XLR mount points. This gives a good start point to eliminate any potential ground loops.
Note - if using separate devices into/out of the dual 1176 you may find these introduce their own ground loops, if mains earthed, and you may need to earth lift your XLR cables at one end. There is a hierarchy in studio wiring for having each output device shielding the cable and lifting grounds on shields at all inputs - this is only for installation cabling not for mic cables as they require the ground connection for phantom power (not in this instance however).

 

[JW]

Thanks very much for the replies. Makes it nice and clear.