Simple grounding question

[J. Larry Hendry]

I am in the middle of re-hab of an old PAiA modular system that came my way
in non-working order.  I am starting from the ground up with the power
supplies.  A complete rewiring of the power supply distribution system is
required.  The old system had a open wire buss across the back of the case
that everything tapped from.  Based on what I have ready on DIY and advice
from John S, I am rewiring the power supply outputs to a star configuration
to reduce noise.

My question concerns the connection (if any) between AC earth and signal
ground.  In this system, earth was not connected at the inputs of the power
supply.  The supplies are connected to 120 VAC via two wire 120V hot and
neutral.  The power supply outputs are mainly +9v, -9v and ground.  I am
connecting these voltages to the modules in a star configuration.  So the
"ground" output of the power supply is connected to each module.  However,
neither the modules or the power supply have any earth connection.

Any suggestions?  Should I isolate the signal grounds to earth?  Should the
ground output at the PS be connected to earth?  Any guidance would be
appreciated.  I am a newbie at this analog low voltage stuff.

Thanks to all for their contributions to synth-diy.  Mostly I lurk and
read.  I am learning a great deal.  And, I would like to publicly thank
John Simonton who sent me some parts including a couple of keys for the
keyboard that were busted in transit.

Larry Hendry