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...
You cannot split the mono out into stereo.
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.

Your receiver has a signal like a preamp output, which is the input to its power amp. For someone with electronic repair skills, it would probably be a minor job to bring this signal out on a pair of rca jacks, and to provide rca jacks for the signal going in to the power amp. If you were not biamping, you would simply use a short jumper between the output and the input, and many recievers have been built with this configuration. The signal may have a relatively high impedance (because it is not intended to drive a lot of wire) but if you use an electronic crossover close to the receiver it will work fine.
Receivers that have configured to use jumpers between pre-out and amp-in usually run with amp disconnected thus cannot be used in bi-amplification.
The skillfull tech should just connect a pair of RCA without disconnecting an input to the amplifier i.e. in-parallel.
Thanks for the ideas, and I am actually wanting to push the subs (should have been clearer), so it sounds like a possibility. I guess my question now is how degraded would the signal become, if at all?
Marakanetz...I don't know what you mean by the power amp being "disconnected". Of course it is until you feed a signal back in.

Dcconners...If you just want a full range signal to feed into a subwoofer amp that has its own low pass filter, a tap of the signal (without disconnecting it from the power amp) would be even easier that what I suggested. However, this would leave the receiver's power amp, and associated speakers, running full range, which doesn't really gain the full benefit of biamping. Also, most subwoofer "plate" amps have provision to input a speaker level signal. If you went that way no changes would be needed to the receiver.
Just put a "Y" cable on the sub out and send the signal to the left and right amp inputs then connect the subs. You will be using the crossover in the receiver.
Maybe I'm missing something. If he wants to bi amp why not use a Y cable on the pre out to split the signal to the second amp. Assuming he is drivng the top or bottom of a full range speaker this is a no brainer. If however he wants to drive a second sub then just put the Y on the sub out. In any event get a good Y cable or jumber. I biamp my home theater coming out of a lexicon with no degradation. Hope this helps.

09-30-04: Walkelin: "Maybe I'm missing something. If he wants to bi amp why not use a Y cable on the pre out to split the signal to the second amp."

You missed: "but my receiver has no pre-amp outs."