i dont see why not, i dont think it will hurt anything.
when i was about 16 we were on the way to a camp site for a week, and i did not have a portable amp. on the way out there we stopped at a local music shop that was out there and i ended up buying a vintage ProCo Rat distortion pedal, i ended up doing just that, and pluged my huge headphones into the output and it worked out great.
On the sansamp original/classic if you push the headphone jack in half way it comes out stereo,this is an intended feature of it. It also sounds great but you have to remember this IS a pre amp pedal not just a distortion or fuzz.
