The Superlux HD-669 Headphones are amazing. It's rated at 100 ohms and would require quite a bit of power from your external amp to get a decent frequency range from. I use this with a Topping VX-1 which isn't ideal for Headphones but it does get the job done. At first it may sound like utter garbage with high sibilance, but give it some time for the drivers to expand. Its recommended you switch the existing earpads with Brainwavz HM5, it does wonders to the listening experience.

I however ...

worth every paisa...i wanna buy another extra pair, just in case current one should die..because as far as i know this set of headphones are very hard to find..i also own hd 668b, impressed by that sound i bought this closed back one, and it sings..668b for CS-GO, 669 for music, movies..and if you care for comfort buy brainwavz round pu-leather pads.

First time i got defferent product.. Second time got real one.. Outside packing was good.. But Product packing was not sealed package.. But inside everything was neat and un touched.. Product is nice. Good LOW frequency response.. Awesome bass and quality for sound.. Good sound stages.. Good for studio reference

Excellent Closed back headphones for recording vocal purpose. Excellent noise isolation. I use it for vocal monitoring+recording, in conjunction with he Samson SR850 (which I use for final mixing). This is very similar to the Samson SR950 (as reported in Youtube, both the Superlux and Samson headphones are supposedly made by the same Chinese manufactured). Anyways its an excellent option.