I'm not LQX but I can answer because I went down this path. I had a Fiio desk amp that had a portable that would slot into it that I used with the 650s for a while. Then I stumbled upon Schiit and got the Magni Modi uber stack and was shocked at how much better the 650s sounded. Everything sounded clearer, audio positioning was better, etc. I wanted to upgrade again later on down the line and got a killer deal on a Valhalla 2 tube amp, a multi-bit bifrost and an HD800S. I still use the HD650s now though, and have my Magni and Modi hooked up to my ps4.
The HD650s really are probably the best sub 1000 dollar headphone I've ever used. The really are fucking amazing. Enjoy your purchase. 220 is a fucking STEAL.
Interesting. I'm content with the E10K for now and like the portability with USB power on a laptop, but good to know it can get even better if I want to go down that road with a desktop solution.
Getting that $20 clearance Brookstone DAC/amp with battery and bluetooth in the mail today, so I'm curious how it holds up with the Fiio. Hopefully well, seems to have a little more versatility with ports and being able to bluetooth with some decent headphones to my TV for watching movies on Plex, Netflix, etc.
If not, I'll just keep it around for the bluetooth stuff. $20 is still what an unamped bluetooth receiver unit would cost, so seems like a neat little toy for the price at the very least.
UPDATE: Returning this thing, not even worth the $20. Worse as an amp than the Fiio and worse as a bluetooth unit than this
$30 TROND unit I got (or $20 if you only need
a receiver unit).
Low end starts to sound pretty bad at higher volumes, clicky knob is not great at fine-tuning like the Fiio with low/high gain switch. Everything in a song just sounds way more individual and distinct with the Fiio. Now I understand what this amp stuff is all about, haha.
For bluetooth, the unit fades the audio in and out for silence to avoid any hiss. Found this out when I couldn't hear clicking for timing during an audio lag test, because the unit wasn't responsive enough to fade in and out to hear it. Bizarre choice, and no way to disable it.
Would recommend the TROND bluetooth unit if you're looking for a simple solution for wired headphones. Doesn't get crazy loud with HD6XX, but gets the job done and decent sound quality with aptX bluetooth. Surprisingly small, too.