Ok, after I got one clear answer from SgtMattBaker here http://www.head-fi.org/t/691115/hd600-driven-by-denon-pma-920-class-a-stereo-amp-what-am-i-to-expect, I had to think it all over:
Which of the following should give me the best results with my HD600:
- SHIIT Magni + Modi
- JDS Labs O2 + ODAC
- Xonar Essence STX or Sound Blaster ZxR (with Magni, O2 or integrated headphone amp)
Thank you in advance for any help with this.