Can I Use One Channel Of A Stereo Power Amp?

You should check with the manufacturer, but I beleive that you can. We used a Crown amp for many years using just one channel without harming the amp in question. More importantly however, I suggest that you choose an amplifier by listening to it and then deciding how it might work in your particular situation rather than choosing one merely for its "spec power" rating. If the first watt of a particular amplifier sounds bad, why in the world would you want 300 more? Just my 2 cents worth. Happy Listening,

I think you can also. Currently I use a Krell KSA 250 stereo amp for the center channel on one side and the sub-woofer on the other side. Occasionaly I disconnect the sub with no apparent problems for the center channel.

I haven't had any problems doing this a few times over the years...there is no input signal into the extra channel, so no signal to output?

A single mono amp is a better option maybe? How about this:

http://www.audiogon.com/cgi-bin/cls.pl?ampstran&1259865296&/Marantz-700-Mono-Block-Like-ne

Note: Not mine, and I don't know the seller.

I agree on the single mono amp. Another alternative is a lower power amp that is bridgeable to provide 300 watts. Just be aware that many amps are not happy driving loads below 8 ohms when bridged, so make sure that either the amp chosen is capable of driving lower impedance loads, or the speaker impedance does not dip much below 8 ohms.