Since the first run has officially started shipping I figured I would split off the discussion of the production version from the Levi.

I really tried to hold back until I had listened for longer but I couldn't help myself from writing down my first impressions.  I have about 5 hours of listening time since I picked the x4 up yesterday evening.  My system is Anedio D2-->2A3x4 w/ Sovtek 2A3s --> HD800 (anax mod 2.0)

To start off this thing is massive and really heavy. Most of that weight comes from the back end, which I am assuming is due to the output transformers.  All told the shipping weight was 60 pounds!  It came nice and tightly packed after the cross continent journey.  I gave it the once over as per Craig's instructions and everything seemed in good order.  After attempting to let it warm up to room temperature after the frigid journey for as long as I could I fired it up and started listening.

I was kind of expecting the clouds to part and the angels to sing when I first hit play.  It wasn't immediately impressive to me compared to my previous amp (Schiit Vali).  I was always surprised that people didn't go nuts for it at the meets that it went to and I now understand why.  The beauty of this amplifier are in the details that would be missed by a casual listen.  About a minute into the first song I did a double take..holy sh1t there was a snare drum in that song that I had never heard before.  I know it sounds cliche but it is true. Since that point I just kept noticing a bunch of little things that have really blown me away.

Anyway here are the things that I have noticed so far:
1.  Dynamics.  Damn this thing hits hard.  The dynamics of the music are better than anything else I have heard so far.  I actually had to turn the volume down a little compared to what I am used to because the peaks have such a strong impact to them.  This may have also had something to do with the overall character of the Sabre DAC coming through.  I also noticed a better gradation of volume between instruments.  When an instrument had a solo I found the spotlight really shines on that instrument.
2.  Soundstage and imaging.  The thing that was the most easily apparent to me was how the snare drum sounds like it is below the cymbals.  That was my aha moment as described above.  Each piece of the drum set had a distinct position.  This was consistent through the tunes I have listened to so far.  This is also the first time I have truly experienced depth in the sound.  There was no doubt the drums were at the back of the recording studio and the other instruments are were at the front.
3. Tonal accuracy and resolution.  I am going to lump these together because I think they both play a role in how natural an instrument sounds.  This is the first time I have heard a realistic piano sound.  Given that I was never happy with the sound of piano I think it is one of the hardest things to capture correctly.  There is a distinct percussive thunk/thwack/resonance on each key strike followed by a natural sounding decay of the note.  This is by far the thing I have been most impressed with.  It is extremely realistic to my ears.  My other test instrument for this is cymbals.  I am not quite sure it is completely there but is certainly not bad.  Just a slight splashiness.   I think this is more likely a DAC or tube problem than a limitation of the amplifier.

That is all for now.  I am excited to hear how it progresses.  The biggest thing for me so far is that the 2A3x4 has shown me so much more from the old 50s and 60s jazz recordings that I love and had kind of written of as just having to deal with less than optimal recordings.  Everything together has really taken them to another level in terms of overall sound quality .  This is both an exciting and scary prospect for me because it means I can use equipment to get better sound and I will eventually feel it is necessary to upgrade everything else in my chain 

Here is my disclaimer about my impressions and the lack of comparisons...I have not heard a lot of high end setups other than the 007 and 009 from a couple of different Stax amps which I didn't really like very much.  Oh and sorry for no pictures but Anax's shot from the Levi thread is excellent and I only have my crummy phone.  This thing is really beautifully made.  I am partial to Craig's industrial DIY design style though.

One last thing.  I have a very slight hum in the right channel.  I am 99% convinced based on a couple of tests I have done that it has something to do with my power bar as I was able to basically get rid of it by unplugging everything else. Probably a ground loop problem.  The other possibility is something came slightly lose in shipping or one of the tubes has gone funky.  Either way I am not concerned because it will be a fairly easy fix.  Since it is not noticeable during the music it doesn't bother me.  I only thought it worth mentioning to solicit some advice from the experienced pirates on how to fix it.

Edit:  Hum was from having the PS too close to the amp.  After moving them apart it is black as night.


UPDATE ON HUM FIX (added by purrin): http://www.changstar.com/index.php/topic,1431.msg37637.html#msg37637