Fisher Tube Amp Center Channel question

I have a Fisher X-101-B integrated tube amp, but not the owners manual. The amp sounds great, but not alot of power. There is a center channel output on this unit. Can that be used for a powered subwoofer, or is this not advisable? Using the unit to drive some satellite speakers and a seperate self powered sub seems like a good approach.

Thank you in advance for your input.

If my memory serves me correctly, this center channel is not a line level out and was designed for a center channel for a big console(these are screw terminals and not RCA's, correct?). You would be better off using the right and left out to the speaker level inputs in the sub and let the sub crossover handle this properly.
There is both a Center Channel RCA output on the top side of the chassie, and the screw terminals for the center speaker connection.
I had a Fisher 400 receiver with the center channel output.I hooked-up a M&K powered sub to the output, and it worked just fine.
Looks like you have a 3 channel amp/receiver. I've seen them on other brands. You probably have 6 output tubes also. I would still probably use the r/l channels into a powered sub with a nice crossover. It won't hurt anything to try the center rca to the sub but how they summed the channels back then compared to a nice sub crossover is a huge difference.
It's only a two-channel amp, with the center channel being summed together. I'll hook it up both ways and see what happens.