[rlivz]

Rookie here, I own a pair of ATH-M50s and after doing a bit of research I'm leaning towards the Swans for my desktop setup. I realize the Swans are self powered and, from what I understand, the M50s don't stand to gain too much from an amp.
 
Looking around a bit with my limited knowledge I haven't been able to pinpoint an ideal DAC/amp unit or combo to get the most of both the headphones and speakers. Any recommendations for under $500, and ideally under $300? Currently, I only have the onboard  motherboard sound.

 

[StratocasterMan]

I'm using a FiiO E17 as both a DAC-only for my 2.1 desktop speaker rig and also as a DAC and headphone amp for my ATH-M50s. It's under $150. Combined with a FiiO L7 line-out dock which is under $10, you'll have a DAC-only line-out signal for your speakers, and you'll have the DAC and headphone amplifier combination for your headphones. I think it's a very hard combination to beat. The FiiO E17 has plenty of power for the ATH-M50s.

 

[Destroysall]

The FiiO E17, or even the E10 are great recommendations. Another few to consider are Audioengine D1 or even the Matrix Mini-i.
 
Destroysall.