To Make a Planar Magnetic Headphone Shine

I purchased a HiFiMan HE-400S over-ear full-size planar magnetic headphone recently. So far, I can't tell its sound quality is much better than the Monoprice Premium Hi-Fi DJ Style Over-the-Ear Pro Headphone # 8323, which is its 1/15 price, after plugging it into either a PC or Denon D-M5S. I can't hear a type of sound space I have heard with a headphone at a headphone demo station in a Costco store. I am wondering whether the reason is a low quality of sound source or an inadequate audio hardware. I have tried the headphone with high-resolution sound files downloaded from the net and I can't tell much difference between a higher resolution and a lower resolution of a same piece of music. I am wondering whether I need to invest on a DAC such as Chord Mojo to let the HiFiMan headphone shine or not.

 

Take the headphones to Costco and see if you are able to reproduce the sound you like. If you can, look at buying the kit that does it. It might be useful to know how many hours you have put on the 400's and finally a PC isn't a great sound source so I wouldn't take that as a guide to the actual headphones.