Pros: Power, detailed unit, and neutral
Cons: Size, good build, but durability is a bit off. cost
Burson had great success with their Soloist discrete amplifier. So following this generation's niche. Let's make it smaller! And so here we have the Soloist SL. Which has one less gain, and input option than the Soloist. It is a discrete class amp. No integrated circuits, just good ole FETs and a discrete power supply. I wish to thank Burson for sending the Soloist SL to me for review and for their wonderful aftersales support which was wonderful.
The Soloist SL is pretty much a solid chunk of 2mm thick aluminum. Everything is bonded together nicely and it is smooth. The back and front panel don't have any build issues in terms of weird streaks, cracks or what not. The Soloist is very 'echo y' when you tap it with your hand of course. As with anything encased in aluminum near completely. Dropping it is not recommended. The buttons on the front felt solid enough as did most of the parts. The volume knobs feel when turning it is quite smooth without much resistance, but still offering some of that low end 'stopping' so that it won't turn by itself of course. The headphone output jack however on the unit I got for review does have some problems. It moves a bit and does cut out one of the channels sometimes(the fix is to turn your headphone cable a bit or to do a slight wiggle). The case's and boards are of course built to a tolerance of +- such and such mm for the volume knob to stick out so it can't be too tight fitting or else it may not fit and other issues. An internal hexagonal ring to secure the headphone jack would be nice though. This of course may just be an isolated issue as this unit is on tour and has been shipped across the entire country and to different people already.
The SL works quite well. It has two inputs availble so that you can connect two DAC's or any analog inputs into the back and switch between them with the touch of a button. It's very simple to use, no need to read the manual even(though I did). The cables that come with it are quite thick, long and blue. They aren't speaker home theater long, but are long enough for a headphone setup. I keep my units close to the wall and the cable did have some problems as it was too thick, meaning I had to move my entire audio set forward so that the cable could have enough space to be plugged in not be hitting the wall. Some may also not like the rear mounted on and off switch. Back when I owned an Audio-gd, my audio setup made this a problem for me as the entire unit was a cm below my monitor. This caused me to have to stand up and reach around to turn on/off the unit. In my new setup, this is not an issue, but I can see how this can be a major one for some. So keep that in mind. You do need to reach to the back to turn it on and off. Having the switch on the front would have looked too tacky is what I think Burson was thinking, because the fronts of them are very minimalist.
I am by no means an expert on electrical engineering and the stuff they teach in it like the differences between everything. Which is why I was sent this unit. But I do have some basic knowledge on IC's vs Discrete's. Discrete units separate out the units or parts such as resistors, transistors and what not into the entire PCB while the integrated circuit(IC) has many of these on the chip itself. These individual proponents means the company that makes the unit more or less has to design EVERYTHING on the unit, and can't just choose to pop in a chip made by TI or AD. This does allow for more fancy, and better units. But of course with such a huge allowance of personally designing the unit comes the risk. The engineers are making the design wholy themselves and are not using chips that have all the functions on it. This means that they must be VERY accurate in making the PCB and how the circuits interact with each other. One wrong move, and the whole prototype pcb is fried. IC units don't have these issues and are much easier to make good units as they have already tested and built IC's from other companies. Discrete designs have to be tested, engineered, tuned and have those steps repeated countless times. This creates a much higher R and D cost for discrete companies(if they don't want to copy other successful discrete diagrams that is). But when done right, can produce great sound. This is basically what Audio-gd and Burson do. The usage of a discrete power supply in the SL also allows them to engineer a low noise PSU and what not. Well there is the beginners lesson of discrete-ness. If I am incorrect in any part, let me know(with sources) please. I am by no means an expert.
I do not use many high end parts. I have owned the Audio-gd NFB 12.1 and have been sent review samples of many other units. The whole point of this tour was to give people that don't use $600 amplifiers the chance to do a write up on them and what not. So this will just be my own thoughts and do not reflect an actual professional review where the reviewer would have had a plethora of knowledge and experience with units at this price point.
For this review, I used the AKG Q701 and LCD-3 and Objective 2 Amplifier. The constant DAC was the Cirrus Logic CS4398.
Starting from the lows, I noticed that the Burson had a less noticeable low range as opposed to the O2, the extension was about the same. Whereas the O2's had more preference, the Burson layered it out and smoothed out the whole range more. The mids however were where I found it most interesting. The Burson's mids are like a pyramid where the tip was at the lower vocals and the base of the pyramid was at the upper vocals. What I am saying is that the tenacity, and presence of the vocals were more thinned out at the bottom and mids and had a more upper vocal sparkle. I personally preferred the O2's more thick vocal range as to the Burson Soloists but of course, this differs from person to person. The instruments also were more brighter on the Burson. Which I am relating to be from the upper mid focus on these. The highs are much more smoothed out on the Burson's than the O2's. The O2's were noticeably more choppy (not able to keep the pitch in a sense) when related to the Burson's. They weren't fatiguingly bright or anything which is what I prefer. I would finally say that the Burson's are more transparent than the O2. Transparency as in which makes it sound more 'real', where it sounds like you aren't listening to a unit, but to the music itself. And this would have to go to the Burson's which had a better layering than the O2's. Layering as in the separation of mids from the vocals.
The Burson Soloist SL is a good transparent amp for those that wish to buy it. The upper mid sparkle is not a favorite of mine, but is to many others so that's really it. It is a smooth and transparent amp that many will like.
I'd say that the Burson Soloist SL with the LCD-3 make a good combo in terms of how well the LCD-3 already layers. But there are better amps for the LCD-3 out there.