Question about the Adcom GTP-450 Ext. Processor Output

What comes out of the Ext. Processor output on the back of the Adcom GTP-450 preamplifier? Is it the signal of whatever the preamplifier is playing, such as a phono or CD signal?
And...
Is the signal coming out of the Ext. Processor output on the back of the Adcom GTP-450 preamplifier able to be controlled by the preamplifier volume control, or does it output the preamplifier signal at full volume with no ability to control it?

I ask, because I want to have two separate outputs coming out of the preamplifier that are controlled by the preamp's volume control, so I can run two sets of speakers through two separeate amplifiers.
Thanks!
Joe