Ground Bus question

[KT]

I'm building a preamp based on Dave Slagle's autoformer volume controls.

The preamp is passive, so there is no provision for power ground. Also, the chassis is plastic, so there is no need for chassis ground.

My question is, if I make a ground bus to connect all the RCA signal input and output grounds, would it be advantageous to make two separate ground rails, one exclusively for the left channel and one for the right channel, or would it be better to have one ground rail on which to connect all grounds?

My thinking is that by having separate ground rails for the left and right channels, that would eliminate one possible ground loop. But I really don't know too much about grounding schemes so any advice would be appreciated.

Thanks,
KT