250 with Sub and headphones?

[maxijazz]

I'm running out of connections with my 250. I have the Atohm GTSE1 speakers and I'd like to try the matching v38s sub rather than SAM to get a bit more low end since moving to a flat with a larger high ceiling lounge (the  bottom end has got lost and SAM seems to make no difference). I don't want to change the Atohms, as they are otherwise great and I don't want big floor standers in the room (or shell out ££).

Config is
Phono- Rega P3
Line 1 - CD Rega Planet
Digital - Headphone amp line out
Ethernet - Air3 Mac Mini

Is there a way to run the sub out and headphones????
Thanks
Brendan

Run sub as "Pre-amplified output mono" and buy a decent headphone DAC (Chord Hugo?), then connect it to "Digital Output (SPDIF). Despite of added cost for DAC/headphone amp I think you will benefit from headphone's sound quality improvement. 

I have my own question to one more knowledgable, though. Is it possible to connect DAC/headphone amp to Devialet's USB?  Would USB work as output? I know it is possible to use it as such, when digitalizing vinyls, but will it work as "USB output" continuously when other inputs are selected?