[Spaceresearcher]

One more important note on the AK120.  Although I haven't heard the new unit yet, I have read that the ability to play with seamless track breaks(continuous play without annoying pauses) is now a reality with the AK120.  The AK100 may have a firmware upgrade available to fix it's issue.
 
In any case this is a really minor issue, the important aspect to these units is the incredible sound playback there capable of producing.  Currently I don't think there's a better portable MP3 player on the planet.
 
It's only other real competitors(please do add more if you know of others fellow Head-fi's) are the Fiio X3 and the Ibasso DX50 and Ibasso DX100(this unit is actually more expensive than the Astell & Kern AK100 but it's competitor the AK120 is markedly more expensive), the only competitors.  The main advantage of choosing one of these three alternative players is the price factor, however all of them have inferior design construction to the Astell & Kern.  Also from reviews I've been checking out on them, none of them can match the Astell & Kern for clarity and crispness(I know a wild word to put to you) of sound.
 
Having said all of this, the important words here are 'quality of sound'.  This in itself is a very personal and debatable topic(one reason I'm always skeptical of reviews that rave about products), the only real way to decide between the players and be 100% sure of your investment, would be to go into a quality audio shop with your favourite headphones you'll be using on the unit you decide upon and try them all out.  The ultimate decider will always be your very own ears.  Your ears are unique to you.  You will interpret sound differently to everyone else.  What one reviewer declares is the next best thing since slice bread, may not be what you imagined it would be or even could be. So when making an investment of this magnitude for a portable piece of HiFi kit, you owe it to yourself to try before you buy where ever possible.  You'll be glad you did.

 

[Spaceresearcher]

One more point on the whole review of audio gear, in this case portable MP3 players with studio quality sound reproduction.
 
Has anyone found a 'decent' audio review site that actually undertakes a serious battery of tests for these units?
 
Most reviews I've come across rave about a few things, give there personal opinions and then quickly draw some conclusions.  Ultimately here's what I believe is a 'decent' review.
 
Instead of just sprouting out opinions and general 'feelings' about the hardware, I always prefer it when there's graphs, figures and actual data on tests carried out to really show the reader in non debatable terms what the hardware is capable of.  Just listing the specs is not really enough, showing a series of definite figures, tables and EQ waveforms applied to the device to highlight strengths and weaknesses is really what is needed.
 
That way you would at the very least have a visual idea of the strengths and weaknesses of the player.  Personally as long as the unit will not fall apart in my hands and is usable I couldn't give a dingoes kidney about the look and feel of the player.  What I'm primarily interested in is what it's capabilities are sound wise.  That's the main reason we all want a sound player right?  So many reviews I read had more rambling about the case and what the reviewer thought of the buttons than factual information about the sound capability of the device.  Then when you get that information it's 'well it sounded really good'.  What does that mean to anyone but that actual reviewer????
 
I'm sure many audiophiles would love to know how the unit performs through 31 bands of EQ for example, is it a treble capable player, is it capable of really good bass note playback or is it more geared towards a uniform mid range playback similar to say studio monitor setups for example.   The reader can formulate there own ideas by being able to see the capabilities of the playback.
 
For this to work the actual played samples for testing would be simple tones and then the output measured.  Perhaps even a sampling device connected to the output.  Then this same equipment would be used with each device to truly give readers some hard core data to make a comparison and perhaps narrow down there listening when they go to try the units out.
 
Once again, the ultimate factor will be your very own ears, however there's no arguing with hard core measurements.
 
The only other possible comparison would be to compare the DAC IC datasheets, however this would not be factoring in the headphone amplifier and connection hardware built into the units which does have an impact on the quality of the sound output.
 
Just a thought that went through my head while being frustrated by lame reviews on these terrific products out there.