Preamp: -0.5db
Filter 1: ON PK Fc 55 Hz Gain 2.5 dB Q 0.9
Filter 2: ON PK Fc 200 Hz Gain -8 dB Q 0.45
Filter 3: ON PK Fc 1000 Hz Gain -3.5 dB Q 0.7
Filter 4: ON PK Fc 8500 Hz Gain -3 dB Q 2
Filter 5: ON HS Fc 9000 Hz Gain -4 dB Q 0.71

I hope the unit variation doesn't prevent this from doing what it should do on your set. You may need to make adjustments for your unit and preferences. This is flagship, endgame stuff, here. The realism is just honestly perfect. The 660S2 has all the technical ability in the world. It just needed some tuning to get some over-emphasized regions out of the way, and put the image into 4D coherence. The detail, image, and stage are all just perfect.

This on a Fiio K7 is a $677 endgame setup for me. There's nowhere to go up from here, in terms of realism.

Load up the EQ, use green mod if that's your preference, play Bon Jovi's "Living On A Prayer" and be amazed at the enormity of the stage, and the huge variety of individual instruments resolved in exquisite detail. It's breath-taking.