correct. you can not use it for just the sub. the zen takes the place of the amp so all the connectors need to plug into itStupid but maybe not a stupid question. Can you effectively utilize a Zen to grab signal for your sub at least for the time being until you build out the rest of the system later? Yes it’s initially 500 bucks or so to grab a pure signal for the subs to start. Not the most logical way to do it. But again a start.
But I have a feeling you will need to completely unplug from the B&O amp to feed the Zen?