I have a preamp from an older Peavey Max bass system.  This amp was basically a CS-800 with a bass preamp together in a rack from the factory.
The power amp is dead on this and I would like to be able to use the preamp with a more modern power amp.  The problem I have, is that I do not know what this preamp requires in terms of voltage, etc.

The preamp has been apart from the power amp for sometime.  My plan was to measure what was being fed to the pre amp from the original power supply, but the fault in the power amp was preventing me from being able to power things up to take a measurement. 

Any ideas?