Rookie Question regarding 3 channel amp.

Moon p-5 pre amp, Vonschwiekert 4 jrs, celeste HT3.

QUESTION: Can i run my 3rd channel as a sub channel by splitting my left and Right outputs into the third channel and running to the Bass units of my speakers
No, don't do that. You need a 4 channel amp...or two stereo amps. You could pick up one two channel amp that matches your three channel amp, and use two of the three channels to go with that (third channel not used)

THats what i thought, but wasnt sure. thanks.