multiple amps 1 pre amp?

kelton, not meaning to get off the subject, but rather responding to S7hortons stating never seen a three lloutput pre.
the hafler JF200 has three. high/low/full ranges. the high and low have freq changeable chips, high freq output has switching to full range option. nifty unit. kurt

Biamping is when you use two channels of power per speaker. For example, I used a Rotel Preamp that powered two parasound amplifiers. One amp ran the tweeters and one amplifier ran the woofers. (Known as horizontal biamping. Vertical biamping is when one amplifier drives one speaker. ie one channel drives the tweeter and one channel drives the woofer.)

This only works if there are multiple binding posts on your speakers. It helps if there are two line level outputs on your preamp. If not, you can create a "y" that turns one set of outputs into two sets. Thus enabling you to send a signal to more than one amplifier. There are some full range speakers that have the ability to be tri-amplified. I have yet to see a preamp with three line level outputs however. I would not biamp without a preamp that has two sets of outputs. I never liked the sound I got when I tried a "Y". Hope this helps.