The Burson Audio Soloist Class A Headphone Amplifier/Pre Amplifier

by Henry Wilkenson on August 23, 2014 · 1 comment

in Amplifiers, Headphones, Stars

Attending listening sessions at dealer showrooms are uniquely beneficial because you can experience a wide range of gear that you otherwise would not be able to hear. It was during such a session at Wes Bender Studio NYC that I encountered a couple of Burson Audio products. It wasn’t the headphone amplifier that first caught my eye—rather, it was a pair of bridged power amplifiers. These turned out to be the Burson Timekeeper amps. At first, their diminutive size made me assume that they were class D amps, but in fact they are class A/B 80 watts-per-channel stereo amps, offering 240wpc when bridged. I was quite impressed with the way these tiny amps were able to drive the big Hansen PRINCE E Loudspeakers to wall-shaking levels, with exceptionally deep bass and good overall sound.

On that same day, I also heard the terrific Audeze LCD-2 headphones for the first time, and quickly requested a pair for review. I also mentioned that I would also need a headphone amp. Bender then offered me the loan of the Burson Soloist headphone amp/preamp that is the subject of this review.

Burson Audio may be unfamiliar to some of you, as it was to me just a short while ago. Burson began in the late 90s as a localized hobby group. The business formed in 2006 designing DIY upgrade parts, along with completed products such as a power amp, preamp, and integrated amplifiers. In addition to the Soloist, Burson manufactures the ‘Conductor’ headphone amp/preamp, which also includes a DAC.

Design Philosophy

Many manufacturers use standardized building blocks. These include IC-based op amps, IC-based power regulators, off-the-shelf transformers, etc. The use of such parts makes designing audio components easier, but it is inevitable that the resulting circuitry will not be optimized for the specific application. 

According to Burson Audio, ‘We tailor design our circuitries from the ground up without any reliance upon standardized parts. From our amplification stages, to our power supplies and transformers, including our purposed built enclosures which are tailor designed for their purpose. The less the equipment tampers with the music, the greater the music becomes. This has been the core design philosophy of Burson Audio since 1996. If the equipment is honest and transparent then the proper tempo, dynamics and tone will materialize as a natural expression of the music and it becomes unnecessary to flavor the original sound.’ Burson Audio has been smart to position itself in the headphone and desktop audio markets, given their recent sharp rise in growth.

Setup And Layout

The Soloist comes with a power cord and one pair of interconnects. Setting it up is simplicity itself. From left to right along the back panel are three pairs of RCA inputs, one preamp output, and a voltage selector switch. Also located on the back is an IEC power plug, a fuse holder (3A), and the power switch. On the front panel, from left to right are the power indicator, the headphone jack output, and the volume control. Finally, there are two buttons that control the input selector and a three-level output selector. The three selections for the preamp output are Low, Medium and High, which correspond to a 7.7dB, a 13.7dB and an 18.2dB output. This also corresponds to 0.18W, 0.7W, and 2W for the headphone amplifier.

Rear panel.

Rear panel.

From the outset, I was impressed with the heft of the unit, especially given its small size (7×10x3 inches). Weighing in at just over eleven pounds, it is obvious that this is a serious piece of gear.

The volume control has a weighty knob with a solid feel. The control may first appear to be of the coarsely-graduated, detented variety, but this is due to its 24 stepped array made by Burson Audio especially for this application. The result is a total elimination of any distortion introduced by the volume control. This kind of volume control is typical of the kind found on far more expensive gear. With the ability to set the output level on the front panel, you should have all of the control you need.

The case is made with extruded aluminum panels, the advantage being that the extruded material is much heaver than cast or billet aluminum, with much more finely finished surfaces, not to mention better heat dissipation. Combined with the high-quality RCA connectors on the rear panel, the Soloist has a very high overall build quality.

Performance

The Soloist had more than enough gain to drive the Audeze LCD-2s to far higher levels than those at which I normally listen. Even a few headbangers that I know might give up. The Soloist could not only play loud, but it was very clean at all levels, with no indication of distress. It always performed flawlessly during my review process. 

Given the performance of the Soloist as a headphone amp, I was anxious to give it a turn as a preamp in my main system. I wasn’t disappointed—rather, I was pleasantly surprised. The Burson more than held its own, even against the five-times-more-expensive VAC preamp. At the price point of the Soloist, I expected more than a few sonic shortcomings, especially since this is a transistor unit, but it never exhibited any edge or harshness. Instead, the sound was just ever so slightly on the warm or sweet side, but not objectionably so. I found the tonal balance to be quite pleasant. I attribute that slight warmth or sweetness to its class-A origins. 

The treble performance was closer to what I typically hear from far more expensive gear. I listened to an excellent recording of Sonny Clark’s, Dial “S” for Sonny (Blue Note TOCJ 6480, Japanese import) that, while mono, is very good. With the Soloist in the system, Louis Hayes’ drumming was outstanding, but particularly noteworthy were the cymbals. Their shimmer, decay, and realism was impressive. Female voice was also surprisingly accurate. Whether it was Cassandra Wilson’s smoky, textured voice or the smooth delicacy of Clair Martin (Old Boyfriends, Honest HonCD5028), female voices were reproduced with considerable realism.

Large scale choral works were handled with aplomb. On John Rutter’s Requiem (Reference Recordings RR-57CD), I could hear the fullness and detail that gave me a clear sense of the size of the Dallas Symphony Center. The massed voices had strong presence. During loud passages, the voices swelled and receded, but never became harsh or hard, fault that I am particularly sensitive to. I especially enjoyed the soloist from on “Pie Jesu.” The purity and delicacy of her voice was truly breathtaking. I have heard this recording many times, and here again, the Burson held its own.   

Another recording that allowed the Soloist to strut its stuff was Wynton Marsallis’ Live at the Village Vanguard (Columbia CXK 69876), a seven-disc box set recorded over seven nights in 1999. There was no mistaking that this was a live recording, as the Soloist allowed all of the room cues to be heard. That this preamp is good at instrumental timbres was witnessed by the brassiness of Wynton’s horn. The same is true for Wycliff Gordon’s trombone, a very difficult instrument to reproduce. It is an instrument that in the past would often make my cartridge mistrack. Once again, I found that the Soloist got out of the way and let the music happen.

The Soloist is also quite capable at presenting a believable sound stage. The stage was quite wide and deep as dictated by the recording. The images within the stage had a more rounded quality as opposed to the overly sharp cardboard cutout quality that some gear will present. The Soloist’s images were much closer to what I hear at live performances is this area.

Bass performance seems to be a Burson specialty. I was impressed with the power amps’ performance in this area, and the Soloist followed suit. Bela Fleck and The Flecktones’ Flight of the Cosmic Hippo (Warner Bros. 9-26562-2) is a great low-frequency test. The astounding bass performance of the Alta Audio FRM-2 loudspeakers allowed me to hear the full power and depth of the bass in this recording. Once again, the Soloist allowed the music to flow into the room and, to some degree, shake the walls. Acoustic bass was also full and tuneful, with all of the overtones presented with coherence and detail. 

The Soloist does get a little more that moderately warm during operation (Class A), but the exceptionally well-designed case is so adapt at dissipating heat that the unit never gets hot. I’m sure that this quality will contribute to the longevity of the amp.

Conclusion

The Burson Soloist is a stellar performer. It wasn’t overly warm or romantic but as I said, it has that Class A touch of sweetness that I liked. Given that the majority of my listening was through the extraordinarily revealing, exceptionally full range Alta Audio FRM-2 Loudspeakers, it was virtually impossible for any upstream component to hide any misbehavior from these speakers.

Is the Soloist the very last word in extension or transparency? No. If that is very high on your sonic checklist, be prepared to spend many times the price of the Burson Soloist to get it. I am at a loss to understand how the Soloist can be built to such high quality, and sell for its more than reasonable price. The folks at Burson are not talking on this point. Given the forgoing, I not only have no problem calling the Soloist an audio bargain and giving it my highest recommendation.

[It is with great pleasure that we award the Audiophilia Star Component Award to the Burson Audio Soloist Class A Headphone Amplifier/Pre Amplifier. Congratulations! - Ed]

MSRP $995.00
Source: Dealer

Reference System

VPI Classic 1 Turntable
VAC Standard LE Preamp w/phono stage
Virtue Audio & Sony 777ES CD players
Gilmore Audio Raptor Power Amps
Dyneaudio Contour 3.3
Alta Audio FRM-2 Speakers
Kaplan Cable Speaker Cables
Acoustic Zen and Siltech interconnects
PS Audio Power Plant Line Conditioner
Echo Busters Acoustic Panels

The Burson Audio Soloist Class A Headphone Amplifier/Pre Amplifier

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Photography by Wes Bender Studio

{ 1 comment… read it below or add one }

admin 08.18.14 at 8:03 am

Great review, Henry. I remember the very first prototypes the Burson boys sent me over ten years ago. They’ve come a long way. Good for them. The kit looks amazing.

Cheers, a

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