I used a Mayflower O2 and e10k with out only (no amp out). Its been amazing. Low gain mode on O2 can drive to pain if thats how you roll. (Only recommended for the mostly deaf metal head like me). O2 is the way. Don't intentionally add distortion to your music, use solid state amps!!

O2 amps and the k612 are a match. No quesrion. As to what else it works with... from my experience all studio monitor style headphones. Sony mdr 7506. Amazing. Neutral accurate headphones will come alive with this. With O2 you will hear what was in the music. Not what the amp 'adds'.

Well said. My JDS O2 is the last desktop amp I will own. Crystal clear amp. IEM to K612s.

Mayflower o2 amp. 130 bucks. Save yer nickles. Never need another headphone amp again.

More power. Grab an O2 amp. Distortion goes away.

I use line out only on Fiio E10K. No amp out. The amp comes from the JDS O2.

That is the beauty of the O2 amp. You only purchase variants in options. By definition an O2 amp has to sound a specific way. Clean. Buy the O2 model with the additional features as you please. But the sound should be the same. O2 is an open source design that by legal release cant be altered...

O2 amp will be a lifetime long purchase for amps. DAC choices are myriad but so long as it does 16/24 by 96 its all good. Rule of thumb. Warm bassy sound from tube amps. Clarity and clean sound from solid state amps. Its all a matter of choice. I use a Fiio e12k. Using line out to a JDS O2...

Save the money up and grab better cans. This is the only absolute improvement that will make your cans 'better'. But please remember that after a point its diminishing returns on your expendature for quality.

This perfectly defines how these cans behave. Bass never 'opened' up for me but if anything became more accurate and subtly deep. K612pros in a single word. Accurate.

Hey, Sound Blaster Z to my AKG 612k gives great positional sound regardless of SBX being on or off. Preference always being whether you like to scan left to right for sound or trust 3D positional orientation provided.

Hey Head-Fi'rs. Just messing around a bit, gotta say. Loving this site.. its helped me a lot with deciding where to go on my initial lay out.    Just FYI. Found a great pair of cans over a Headphonebar.com in Vancouver BC. Got a demo pair of AKG K612 (For 90 bucks!!) with a Fiio E11K and Its...