[sdiy] Why dual grounds?

[JH.]

>I can't speak for MOTM, but Paul Shreiber often posts to the list.  As
> the Oakley pdf referenced by Graham indicates the two MOTM connector 
> grounds are joined on the board. I'm guessing Paul would say if your board 
> layout is correct, and your power distribution is good, then you don't 
> need separate clean and dirty grounds back to a star point.

Well yes, that's the *other* method to keep the system clean: keep the dirt 
local.
With clever use of bypass capacitors you can keep the "dirty" currents from 
travelling far across the GND plane, just as you prevent them from 
travelling far across the VCC/VEE net.

JH.