Alright folks, I have spent a good deal of time the past couple of days listening to the Burson.
Reviewing the basics, this is the Conductor, but fed from my Emotiva XDA-1 DAC, not the internal sabre DAC. Using the same cheap cables as fed everybody else. Per experimentation earlier, the amp was set to low gain. I had left it on constantly for a couple of days, just to make sure it was definitely warmed up.
Let me start by saying that I had a hard time establishing a solid SPL on this amp. Set to the 67 dB that was the upper limit on the other amps tested, the Burson sounded too soft for critical listening when playing the Ellington disc. Hmmm. Upped it one notch. Still too soft. Upped it 2 notches. Then a third. The sound finally came alive, but the bass on Satin Doll was a bit boomy. The amp was at 3 notches past 12 o'clock, approximately the 2 o'clock I had been using before I started matching SPLs. But the white noise SPL was now at 80 dBs per my phone app. Whatever. I decided to just use whatever level the amp sounded best at, but I found that the right level varied by recording. This amp has a very narrow sweet spot. Not enough volume and it sounds soft, damnear dead. Too much and you start to hear harshness, at least when using the Emo DAC input. Just right and the bears finally get to eat Goldilocks. Or something like that.
Okay, now to the sound itself. I decided to listen to the Ellington at 2 notches past 12 o'clock, and just concentrate harder, because I didn't like the boom in the bass. That turned out to be the right decision, since on Satin Doll, the bass tightened up. The cymbals were a bit quiet, but sounded right. You could hear stick hitting metal. The piano also sounded right. There was no harshness and the detail was all there, just much more subtle than on the MJ.
Everything sounds distant on the Burson, like you are sitting in the back of the theater, instead of the front, or with some amps, on the stage. Some would say the Burson has a larger sound stage, I say it puts you in the cheap seats. But hey, for those people who don't want to be in the band, pay a premium price to sit up close and see how haggard a 60-year-old rocker really looks, or risk getting hit by flying guitar splinters, the Burson might be perfect. It sort of turns the LCD-3s into the HD800s, without the high-end issues. Not at all bad, depending on what the listener wants from his/her headphones.
The amp does handle the high end extremely well. Cymbals and snares sound absolutely fantastic on this amp, and the higher notes on all of the instruments are clean with no harshness -- assuming you have set the volume level properly (always keep that caveat in mind with this amp, please). Bass is also very clean and tight. Kick drums have great, distinct thump and both acoustic and electric basses sound right. It is easy to pick out the various instruments playing in the lower octaves on pretty much every song.
Instrument separation is extremely good with this amp throughout the audible range. If you want to listen to the drums or clarinet or guitar all the way through a song, the Burson makes it easy, as long as you pay attention, because everything is very subtle, assuming the right volume level.
Sounds like an awesome amp, right? Well, maybe, if you listen to instrumental jazz or classical music. But this is not a very good rock amp. The mid-range is kind of dead, even at the "right" volume. And you don't dare kick it up a notch on your favorite tune, because the "reward" is not just more volume, but very intrusive harshness. And while I'm talking about volume, let me whine about the stepped volume control. I don't like it. For an amp with a very small sweet spot, not having infinite control over the volume is a bad thing. There were times when I really wanted to be in between steps, but that isn't possible. In addition, and this is a minor complaint, there is a static noise in between each step. It isn't doing any harm, but I would prefer silence between steps.
More on the dead mid-range. Voices sound distant and cold, whether the singer is Harry Connick, Paul Simon or the others on Graceland, Mumford and Sons or Dave Matthews. I listened to a lot of Dave Matthews on this amp, because his early recordings tent to be very clear and mid-centric. Not on the Burson. Keeping the amp in the sweet spot meant changing the volume on nearly every song, and even then the mid-range was not alive. Guitars and ukeleles most often sound thin. Horns sounded a bit harsh, probably because I had the volume too high because I wanted the mids to come to life. Even on jazz recordings, my notes indicate that the piano often sounded thin and cold... not awful, not really harsh, yet not smooth. Just not right. Same with vibraphones, trumpets and saxophones on most songs. Not horrible, just not quite right.
I put on my old reference, Sonia Dada's "A Day at the Beach" a very well-recorded album in my view, with a wide mix of voices and instruments. The LCD-3s really love this album... but not so much with the Burson. The sound was distant, not very inviting. When I cranked it a bit, it became more involving, but some warmth was missing in the voices. The drums sounded great, as always with this amp. Bass was fine. Even the piano sounded okay. but the voices were just not well represented.
The verdict: The Burson Soloist is an excellent amp for instrumental jazz, and probably for classical, though I didn't have time or the inclination to listen to any classical music during these sessions. I would guess that small ensembles would sound fantastic, and even full orchestras would sound very good. But opera would probably not play to its strengths. In general, it provides a large sound stage (too large, for my preference, but YMMV), great instrument separation and excellent, though subtle, detail. Highs and lows sound superb. The mids are not anywhere near as good. This amp has the classic U-shaped sound signature, and while I like it better than the Emotiva Mini-X (which, interestingly, has the exact opposite issues -- mids sound better than the lows and highs), or the Mjolnir, it doesn't suit my listening preferences, and thus I won't be buying it. But it is a very fine piece of hardware, and I can understand why lots of people really like this amp.
Next up: I'm gonna use the sabre DAC in the Conductor and see if I like it enough to recommend the combo (for $1850... OUCH), because if it can fix the mid-range problems, it might be a really good setup.