Bi-amping with no pre-outs


I would like to add an amp to push the woofers in my NHT 2.4�s, but my receiver has no pre-amp outs. What it does have however is a single sub out, which I use for its intended purpose and would like to know if it is possible to split the signal for bi-amping purposes? Possibly to an Adcom GFA...
dcconners
I have seen "Y" split xlr, & single ended cables for sale on audiogon custom made, & terminated just for this purpose.
Not for this. He wants to bi-amp his NHTs and there's no way to get 2 stereo outs for the woofers (not the subwoofer) from a mono source.

The only solution I can think of is to go to an auto/stereo shop and get a pair of speaker-to-line level adapters. But I ain't vouching for the quality of the results.

Kal