XPS 15 Headphone quality

I'm looking to upgrade to the XPS 15 and have read a lot of praise for the speakers, but haven't seen anything about the sound that comes through the headphone jacks. I'm a bit more likely to use headphones than speakers most of the time and am wondering if these jacks well-powered, or does the audio from the jacks not compare to the built in speakers? I never realized how anemic my current XPS 1530's audio through the jacks are until I plugged it into my phone (which makes it more sad) and realized how much more powerful everything plays. Can anyone comment on the quality from the XPS 15?
For reference sake, I've been using Sennheiser HD500 (old, I know) headphones.

 

The latest XPS doesn't contain a discrete soundcard, just the onboard Realtek chip (which is quite respectable actually). How beefy the 3.5mm output is, is anyone's guess. If you care about audio quality though, I recommend you invest in a USB Dac with integral headphone amp. Something like this:

NuForce Icon uDAC-2

Hope that helps.

 

Actually, the sound card supports 5.1. First headphone jack = front, second headphone/spdif = sub/center, mic = rear. When I plugged in headphones, the waves software asked me what I wanted to use the jack for (mic or rear or line in for example). The middle jack can act as headphone, front, rear, center/sub or s/pdif out the first headphone jack can act as headphone or front.

The headphone quality is good in both headphone jacks, they sound the same. I wouldn't be able to tell you how well this 5.1 works, cause I don't have 5.1 speakers with me.

 

MaxGhost, would you like to run RMAA and post the results here? 24 bit 44100Hz loopback test (using a cable with 3.5mm jack at both ends) would be great.