connecting a sub-woofer to a preamp

I recently purchased an Ayre K-5xe MP preamp and would like to connect a sub woofer to my system to augment the bass response of my ET LFT-8 speakers. Previously with a YBA preamp this was just a matter of utilizing one of the additional output jacks.

However with the Ayre this is not the answer.

Does anyone have any suggestions? The Owner's manual is silent in this regard. I've also e-mailed Ayre twice over the past ten with this question and am still waiting for the courtesy of a reply...

Thanks in advance for any advice that you may care to pass along...

Peter