WASAPI----->Bitmatched/Perfect transport----->Maverick D1 RCA SS output------>Matrix M-Stage(Stock)----->AKG K-702

I use these with my AKG K702 headphones and there really isn't much to say.  My previous amp had no problem powering these bad boys either but it hissed and popped at the volumes necessary to do so.  With the dip switch on the bottom controlling level of gain you can be assured it will power your most sensitive headphones equally to your power hungry hogs.

The volume knob is solid construction, and its potentiometer is completely linear.  Meaning you can fine tune to the perfect level of volume for detail extraction without killing your ears.  Case construction seems solid, though it does get hot which is probably due to the case  acting as a heat sink since it is after all a class A amp meaning it does get hot.  Nothing to be really worried about though.  I took half a star off for design only because the blue LED is the most blinding LED I have ever laid my eyes upon.  It is powerful enough to make my white shirt glow blue at night.

At higher than normal listening volumes with no music playing there was no noise or hiss on this unit through my headphones(silence).  At listening levels exceeding high and entering headphone damaging/ear damaging levels  there was a slight hiss.  But it is irrelevant considering at that volume you won't have the ears for headphones anyway.

Matching levels to my previous amp there are details that I can hear in some of my songs.  On the m-stage I confused them for static initially because I was not aware of their presence before.  When fine tuning my ears to comprehend was I was hearing it definitely was part of the song and not static.  Details that my other amp could not pickup at its maximum tolerable volume.  It also has a slightly higher level of clarity to every sound than my previous amp.  It is not a huge difference but it exist and is easily audible to the point that it was not placebo. (Previous amp was the HPA of the Maverick D1).

I gave it a 4/5 in Value because soon all in one units while slightly more expensive are able to handle multiple tasks.  Such as being a transport, a DAC and an HPA and doing all three proficiently.  But if you only need a stereo RCA headphone Amp for $250 you are getting something quite special.  It has changeable gain, and two inputs as well.  If can function as a pre-amp in the future as well.

I gave it a 4.5/5 for audio quality because while I feel it sounds perfect as is it is impossible to measure that since I have not owned enough equipment.

I gave it a 5 for overall quality because it performs as an amp should.  It is powerful, silent, and clean.

Overall its worth the $250-$290, definitely not something you will want to upgrade for a long time.  (Balanced inputs/headphone outputs? Ear Speakers?)

Edit: This review would probably make an English teacher cry.  I will come back and fix it up one day, wrote this while tired.

http://www.head-fi.org/forum/thread/475618/matrix-m-stage-amp-review-simple-cheap-and-excellent

That's a link to my full review, which has become a very long thread.

In summary:

The M-Stage is a clone of the Lehmann Audio Black Cube Linear, which is a high end headphone amp selling for around $1k. The M-Stage matches or exceeds the real thing in every aspect. It features a socketed opamp in the output stage so you can upgrade or try different things yourself (the Lehmann does not allow this). It is built like a tank, perhaps not the most pretty thing in your audio setup but it does have a certain utilitarian charm. At this moment I think this is one of the best choices out there for people to experience high end sound at a reasonable price.