There are adaptors by Russound, Antique Sound Labs and others that will allow you to do this with headphones for about $100. This way, you can use any headphones.
The other option, if your pre-amp has enough output voltage, is to buy coax to 1/4" or 1/8" adaptors at radio shack so you can hook up your headphones directly to the pre-amp outputs and skip the amp altogether. Beware, some headphones are much easier to drive than others.
The other option, if your pre-amp has enough output voltage, is to buy coax to 1/4" or 1/8" adaptors at radio shack so you can hook up your headphones directly to the pre-amp outputs and skip the amp altogether. Beware, some headphones are much easier to drive than others.