Nope.

The O2 is basically noiseless.   Max out the digital volume to 100% and then carefully use the volume knob on the O2.

If high-res was actually hi-res instead of an idiotic waste of space then this would be cool. . . but it's not.

I am listening to LCD Soundsystem on my LCD-2's.   

The HD 650's have more upper mid-range/lower treble than anything else so that can explain why they can be perceived as having a lack in bass or upper treble.

EQ:     cable:   http://www.ebay.com/itm/261579921982?_trksid=p2060778.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT

All you really need to know is that DAC's and amp's designed in a sane way can be completely transparent unlike headphones.   Power requirements are also pretty straightforward.

If you think all headphones sound the same in terms of distortion that is just sad.

There is an obvious difference between headphones with 1% distortion and 0.1% distortion. That's like the difference between what audiophiles call "low-fi" and hi-fi" right there.

Yes, research HE WHO SHALL NOT BE NAMED because no facts allowed.

This is noiseless.   https://www.mayflowerelectronics.com/shop/digital-to-analog-converters/objective2-with-odac/

  I agree with all of this. :)

HD 558.

HD 558.

I really cannot get over how good these sound after a couple of weeks I am still amazed. . . they sound very nearly real.

  Everyone should know that the HD 650's are more musical sounding.

  Nonsense. The HD 650's have a very distinctive smooth sound signature that has nothing to do with the FR.

The HD 650's have a much more natural sound signature. The FR is irrelevant because you can easily EQ them.

The HD 650's are far more natural sounding, the HD 600's sound sterile in comparison.

Use the HD 580/600's obviously, forget Beyerdynamics. :|

I am still playing TF2 because nothing better has come out since that game. It's more than game. It's a hat/conga/whatever simulator.

Here are my thoughts.   Objectively: Sennheiser and Audeze headphones measure better than anything else according to the data sheets at inner fidelity. The LCD-2's have better measured performance than any dynamic headphone including the HD 800.   Subjectively: These are also the top brands...

Ridiculously inaccurate FR's are not uncommon even among supposedly high fidelity headphones so this should not be surprising.    The FOTM HJE900's come to mind.

THD is THD.   The mid range is in fact where distortion is the most audible.   Any distortion in the mid range exceeding 0.01% is in fact audible and this proves that transducers sound different.   Listen to the LCD-2's and you will hear what minimal distortion in the bass sounds like.