Forte FT 1 as a biamp

Hi all,

I have a Forte FT 1 five channel amp that I would like to use to biamp a set of Usher CP 6371's . The pre amp is an Audio Research SP-9 MK III. The Forte has three channels at 125 w  and two at 55 w . I was planning to use the 125 for bass and mids and the 55 for highs. Is this a workable situation or am I rowing upstream ? I usually use a Manley Stingray on the speakers bi wired. I got the Forte as I am  looking to play around with class A vs tube ? Any thoughts ?