Headphone Amp Comparison (XM5 vs Total AirHead)

Everyone is probably wondering what the heck is a XM5 ?  The XM5 is a headphone amp.   Headphones have portable amps.  They  really improve the sound of any good pair of headphones. This is second headphone amp  I purchased.   The first  amp I  owned was the Total AirHead.  by HeadRoom.  It should be noted these gizmos can get very expensive.

The XM5 cost me $300 US  The Total Air Head wad about $175 US.

Here is the review:

Amps: XM5 and the  Total AirHead
Player: 4G Nano iPod
Headphones: Beyerdynamic Dt 770 PR0  80 OHM
First my ipod is on full as was XM5. The XM5 in the experiment is on cross feed too.
So I will compare different music.

Rock Music
Jimi Hendrix: Axis Bold As Love:EXP                                                                  Jefferson Starship: Blow Against the Empire : Hiijack
At full blast XM5  0 distortion, it could be a bit louder
Jazz
Miles Runs the Voodo Down
On XM5 at full blast, some distortion. At 50% bass strong volume acceptable
Ambient
Mystical Sun
2012
On the  XM5 at full blast some distortion is apparent. At 50%, bass and treble are very good as well as the volume is acceptable.

Pure
On XM5 at full blast- little distortion. At 50% strong bass and good treble at an acceptable volume.
Classical
Mars- The Planets - Conductor Simon Rattle
On the XM5 at full blast I found it wanting.Pushing in the 10+ gain made it better .
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AirHead Results
Classical
Mars-The Planets-Conductor  Simon Rattle
On the AirHead, I found the volume wanting at full blast
Ambient
Same CD ''s  for the  XM5  test
I found on the Air Head  volume on full -wanting... It was more like a 6 or 7.
Jazz.
Miles  Run  the Voodo  Down
I found the volume wanting.   Though  the bass is strong.
Rock
Same  CD's as the  XM5 test.
Strange  enough   the results are  similar to the XM5.
Conclusion
I  would say  the XM5  is better amp than the Air Head.