Other equipment used in this review
Headphones: Audeze LCD-3, HiFiMAN HE-500 and HE-6, Sennheiser HD 800, and Shure SRH 1440 and SRH 1840.
Earphones: Ultimate Ears IERM and PRM
Source components: Oppo BDP-95 universal/Blu-ray player, NuForce-edition Oppo BDP-83 Special Edition universal/Blu-ray player.
Power amplifier: Anthem Statement P5 (left and right channels only)
Speakers: PSB Imagine T2 floorstanding speakers.
The Soloist as headphone amplifier
More so than was the case with the HA-160 amplifier, the Soloist seemed to need a fair amount of run-in and warm-up time in order to reveal its full sonic potential. Straight from the box, the sound is not unpleasant and showed flashes of real brilliance, but tended at first to be a bit warm and opaque. As playing time accumulated, though, the Soloist opened up and became progressively more transparent sounding in a most convincing way.
Heard at its best, the Soloist offers a lively and energetic sound, with excellent control over both macro- and micro-dynamics, plus—thanks to the Soloist’s three-level gain switches—the ability to dial-in power and gain-on-demand sufficient for even the most difficult to drive headphones (the Soloist comfortable drives the HiFiMAN HE-6 without any apparent stress). I found that with most headphones, the best approach was to set volumes at moderate levels and to toggle through the Soloist’s three gain settings until I found the best combination of adequate power and low noise for the headphone at hand. (Your ears will tell you right away when you’ve found the best gain setting for a given headphone, though it’s easy to toggle through settings if you wish to experiment further). One upshot of having a range of three available master gain levels is that the Soloist can work equally well with very sensitive headphones on through to ‘phones that are extremely low in sensitivity and hard to drive. The Soloist is more powerful than, but also more flexible than, the HA-160—two meaningful differentiators prospective buyers may want to consider.
Next, the Soloist sounds highly transparent and detailed, even more so than the already very good HA-160. I noticed these differences all across the audio spectrum, but especially in the very heart of the midrange. I would liken the difference between the Soloist and other good headphone amps near its price to the difference between looking at a beautifully shaped three-dimensional sculptural object vs. looking at a fine, but ultimately flat, two-dimensional photograph of the same object. Both have gorgeous lines, textures, shadows, details, and so forth, but at the end of the day the sculptural object conveys a believable sense of depth, contours, and solidity that even the best of photographs cannot fully match.
So it is with the Burson Soloist. Other fine headphone amps (e.g., the very good though somewhat more expensive Audio Electronics/Cary Audio Nighthawk) may initially seem to provide more crisply drawn leading edges of notes or greater definition, but the longer you listen to the Soloist more aware you become of the almost sculptural shadings and inner details the Australian amp provides, Moreover, it does a great job with the complete envelope of each note—not just with leading edges but with the whole note in its entirety, bringing to each element a great combination of delicacy, finesse, and power. In the end, the superior three-dimensionality, solidity, and whole- -note completeness of the Soloist are what set it apart from, and in my mind place it above, its like-priced competitors.
Voicing: At first the Soloist give the impression of providing tonal balance tipped slightly to the warm side of neutral, owing both to the Soloist’s ample bass output and unexaggerated highs. After a closer listen, I feel the first impression is illusory and that the Soloist is actually quite neutral in its presentation. It’s just that it has robust bass output (and especially mid-bass output), where many other headphone amps tend to sound a little thin, and it also steadfastly refuses to use upturned highs or exaggerated treble transients to create a sense of heightened detail. Once you get acclimated to the Burson’s sound, some competing amps can seem a bit brittle and anemic-sounding by comparison.
The Soloist as stereo preamplifier
The Soloist’s virtues as a preamp run parallel to its strengths as a headphone amplifier, but with this difference: the superiority of the Soloist’s three-dimensionality and soundstaging are, if anything, even more obvious in the context of a full-size hi-fi system. When I tried the Soloist as a preamp, I found that it produced broad, deep soundstages with the greatest of ease and with virtually no tendency for the sound to “cling” to the front baffle surfaces of the speakers. What is more, the placement of instruments within soundstages was remarkably precise and well focused. Overall, the Soloist yielded up a sound that was both more natural and more refined and much more three-dimensional than I’ve heard from other preamps in its price class. While a few products designed as preamps first and as headphone amps second may have more features (as in more inputs and outputs, recording monitor loops, and remote controls), the fact is that the Soloist effortlessly stands tall in their midst in terms of pure sound quality, which is precisely what Burson intended.