Quick PSU query.

[bikerhifinut]

Heres a thing.
I am roughing out an experimental circuit. I have a nice toroid that has 6.3V, 240V and a useful 9V secondary at low current but would support a remote control circuit and a handful of op amps if I needed it for a hybrid circuit.

So this is the question, I have a few good quality 5 pin with separate metal earth outers plugs and sockets for the Umbilicals.
Obviously the heaters take 2 pins, with their elevated reference done at the PSU. That leaves 3 pins.
As signal earth/0V is common is there any reason why I shouldn't have a single common return to the PSU and have the HT and Low voltage DC 0V commoned at the PSU and use the 2 remaining pins for the positive supplies?

It saves a pair of plugs and sockets and a bit of rear panel space. or the expense of a 6 pin plug and socket before anyone jumps in with the bleedin' obvious........

Andy.