[sdiy] RFZ gear - negative voltage power supply?

[jure zitnik]

Greetings, list!

I'm sitting here in front of three ancient RFZ console modules, trying
to wrap my head around this.
I want to put them in a single enclosure and power them all from a single PSU.

the modules are:
1x W735/1 (a two channel 7-band EQ)
2x V740/1c (a mono preamp)

I have some vague info on the pinout and it says they take just a
single -24V line for power...

Now how exactly does that work? Can I just take a normal AC-DC 24V
supply, hook the +24V to the module's ground and the supply's ground
to module's -24V input?
Does anybody know these specific modules? I read somewhere they don't
even need regulated voltage... any ideas?

Thanks a bunch,
jure