The Australian firm Burson Audio may not yet be a household name, but if you’re serious about headphone sound quality you’ll want to make their acquaintance sooner rather than later. Here’s why. The men from Melbourne are passionate (and I mean really passionate) about sound quality and they’ve devoted years and countless hours developing highly specialized, ultra high-quality components whose sole (or should I say, “soul?”) purpose in life is to help high-performance headphones be all that they can be. A perfect case in point would be the gorgeous Burson Audio HA-160 headphone amplifier ($695) that is the subject of this review.
Before we dig deeply into the sound and inner workings of the HA-160, there are a couple of things you first need to understand about Burson. First, it’s important to grasp that these Aussies (bless their hearts) just plain can not and will not allow themselves to settle for circuit designs they consider to be compromised, either in terms of performance or build quality. If you spend any amount of time on the Burson Audio Web site, I guarantee you’ll find the word “uncompromising” used early and often, and once you see the innovative thinking and self-evident build quality that goes into Burson products, you’ll grasp in an instant that these people are serious—not just blowing marketing “smoke.”
Second, the Burson folk care deeply about craftsmanship, not just because they want to build products in which buyers can take pride of ownership (although that factor is no doubt at work), but also because the Burson team sees—and more importantly, hears—a direct connection between superior parts quality and workmanship and the desired end result: namely, great sound. Implicit in the Burson approach, then, is a certain unmistakable willingness to “go the extra mile” where questions of sound quality are involved. Thus, the Burson team tends to reject design and construction “shortcuts,” no matter how well intended they might be, if there is even the slightest possibility that they could limit sound quality in any way. Stated simply, Burson always puts musical enjoyment first.
Finally, and this part seems downright weird (though in a good and refreshing way relative to the norms of the high-end audio industry in the U.S.), Burson is big on value. Their products are essentially handmade and quality control checked to an almost lavish extent, and yet—quite amazingly—they are sensibly priced. While the $695 Burson HA-160 is by no means cheap, I can’t help but think there are plenty of companies out there who would charge more, and I mean a lot more, if they were to offer comparable products. If you listen to the Burson HA-160 for any length of time, you may come to feel, as I do, that it’s a bit like getting a Bentley Continental GT for the price of, say, a heavily-optioned Buick (no disrespect to Buick intended). How cool is that?
Consider this headphone amp if: you want what is arguably a world-class headphone amp (complete with exquisite build-quality to match), for a price that is more than fair. Look to the Burson if you favor an extremely neutral and revealing amp, and one that offers terrific image density and the ability retrieve tons of low-level detail. Finally, consider the Burson if you want an amp that works well with a remarkably wide range of headphones, regardless of the various impedance loads they might present.
Look elsewhere if: you know and love fine tube-type amplifiers, and would therefore prefer a tube-powered design. But be aware that, whether you favor tube or solid-state designs, you’ll likely wind up spending considerably more than the HA-160 costs in order to have any realistic hope of achieving superior sound.
Ratings (compared to similarly-priced headphone amps)
•Tonal Balance: 10
•Flexibility: 10 (offers dual output jacks, each optimized for a different range of headphone impedances)
•Value: 10 (in truth, the Burson is a bargain for the quality on offer)
The Burson HA-160 is one of those products where, as the saying goes, “God is in the details.” We don’t have space to do full justice to the many detail touches incorporated in the HA-160 (for that, you’ll want to visit the Burson Web site), so the following represents a condensed list of highlights:
•HD Opamps: As a signature feature, the HA-160 (along with many other Burson products) uses class A circuitry and what the firm terms HD Opamp modules that are based on hand-picked discrete devices—not on garden-variety integrated circuit chips. Burson adamantly maintains that IC-type opamps are incapable of genuinely high-level sonic performance, and thus offers an alternative. Burson’s HD Opamps feature precision-matched transistors, 1% tolerance resistors, ultra high-quality capacitors, and so on. Many components within the HD Opamp are chosen through an expensive and time-consuming “burn-in-then-match” selection process, which ensures that incredibly tight tolerances are maintained. Burson even assembles its modules using special lead-free solder and a temperature-controlled soldering process, rather than using the sort of generic wave solder bath that is commonly used in construction of mass market electronics.
•Low noise power supply: As with its opamps, Burson eschews IC-based power supply regulators for its power supplies, instead choosing to use discrete devices to create a “sophisticated noise filter and voltage stabilization system."
•High-precision volume control: Rather than use a conventional potentiometer for the HA-160’s volume control, Burson builds its own 24-position stepped attenuator that, again, uses precision-matched resistors. The argument is that a well-made stepped attenuator can do a superior job of preserving sonic details from very low-level audio signals. No remote control is provided, since Burson claims that remote controls almost invariably introduce unwanted noise that muddles the audio signal, at least to some extent.
•Resonance Free Aluminum (RFA) Enclosure: The HA-160 chassis is made up of panels precision-machined from slabs of aluminum, each designed to have a slightly different thickness and thus a different resonant “signature.” The case not only serves to resist mechanically induced noise, but also makes a great heat sink, thus allowing Burson to run higher idle currents in its amplifier modules. Higher idle currents, in turn, are said to help yield “lower distortion, higher output, and better overall dynamics.”
For this review we did much of our listening through four very revealing full-size headphones: the Audeze LCD-2, the HiFiMAN HE-6 and HE-5LE, and the Shure SRH840. I also used several very high-performance custom-fit in-ear monitors, including the Westone ES5 and Ultimate Ears In-Ear Reference Monitors.
Source components included: a Musical Fidelity kW SACD player, an iPod Classic with digital outputs fed through an HRT iStreamer DAC, and an analog system consisting of an Nottingham Analogue System Ace-Space 294 turntable/Ace 294 tonearm fitted with a variety of Shelter moving-coil phono cartridges (the 901 MkII, 9000, and Harmony MC), with cartridge signals fed through a Fosgate Signature tube-type phono stage.
I auditioned the Burson Audio HA-160 both with and without its optional, outboard Burson Audio AB-160 RCA buffer stage*.
* Note: The AB-160 RCA will be the subject of its own Playback mini-review that we hope to publish in the next few weeks.
The Burson serves up a dead neutral, full-bodied, and highly detailed sound that is immediately engaging—deeply so. The unit needs a bit of warm up (about a half hour or so) to sound its best, and in an absolute sense sounds subtly smoother with more fully saturated tonal color after it has been allowed to run-in for a week or more. In fact, I’d follow Burson’s suggestion that you leave the HA-160 powered up all the time, so that it’s always ready to go. But now, let’s take a moment for a closer look at the sonic qualities I’ve sketched out above.
Neutrality: It’s tempting and in many cases easy to describe components in terms of minor ways in which their response curves are skewed, even if only very slightly, away from strict neutrality. But this is not the case with the Burson. The Burson sounds about as perfectly balanced from top to bottom as any audio component I can think of and, significantly, it maintains this balance regardless of the load being driven. Burson flatly rejects the notion that you have to match headphone amps to specific headphone loads, arguing that a well-designed amp can and should be able to handle any reasonable load. In practice, this is one of those things easier said than done, but the HA-160 not only talks the talk, but also walks the walk.
Full-bodied presentation: Some headphone amps sound “happier” or more at ease when facing certain kinds of musical challenges than others. For example, some are great at delicacy (solo female vocalists, solo violin, etc.), yet wilt when the going gets down’n’dirty (e.g., Fender Stratocaster at full song backed by a scorching-hot rhythm section, also at full song)—or vice versa. But again, this is not the case with the Burson. No matter what challenge you give it, the HA-160 consistently responds with equal measures of finesse and with pleasingly rich and properly saturated (but not exaggerated) tonal colors. It always sounds poised and comfortable with itself, as if it’s got additional reserves of power and speed in reserve, should you ever require them.
Highly-detailed: Exquisite detailing, folks, is the quality that really defines the Burson. Depending on which headphone amps you’ve heard in the past, you may well be floored by the sheer density of low-level sonic information that the HA-160 can pull from what you thought were familiar recordings. It’s an impressive and intensely rewarding thing to hear. Interestingly, though, all of this extra information does not carry with it any sort of hidden sonic price in terms of upper midrange/treble edginess or stridency. On the contrary, the Burson is unfailingly smooth. I won’t tell you the Burson is the most detailed or revealing headphone amp I’ve ever heard, but I will say that those few I’ve heard that can equal or perhaps surpass the Burson invariably seem to cost more—often quite a lot more.
One further point I should mention is that the Burson is powerful—enough so that it can even drive the extremely power-hungry HiFiMAN HE-6 planar magnetic headphones. Apart from electrostatic headphones, which typically must be driven by purpose-built amps, the HA-160 can drive pretty much anything you’d care to throw at it.
One disk that shows the deft manner in which the HA-160 navigates texturally challenging material is the eponymous jazz recording from Floratone (Floratone, Blue Note/EMI)—a band in which eclectic guitarist Bill Frisell and his cohorts figure prominently. Many of the tracks on Floratone serve up what I’ve described in the past as “angular otherworldly melodies” that are supported by a broad variety of both acoustic and electronic instrumental embellishments—some of them dark and hypnotic, other lighter and more evanescent. The result is a densely layered sound that is beautiful and intoxicatingly complex when properly reproduced, but that runs the risk of becoming—through some amplifiers—a compressed, formless mish-mosh of sounds. But with the HA-160, no such problems arise.
I used the Burson in working on my recent Playback reviews of the HRT iStreamer DAC and of the Ultimate Ears In-Ear Reference Monitors, playing the tracks from Floratone through both products with great results. Here’s what I wrote about the sounds the Burson helped the HRT and Ultimate Ears components to achieve:
“…on the track ‘Swamped’ from Floratone … you’ll immediately hear the round, sweet, and somewhat chime-like signature sound of Frisell’s guitar take up the melody, supplemented by the deep, earthy growl of a syncopated acoustic bass line and a clear, simple rhythmic pattern played predominantly on the percussionist’s high-hats and snare drum. What’s so pleasing about the … presentation on this track is that each instrument is given its due, so that each sounds full, complete, and three-dimensional—independent of what the other instruments are doing. Nothing is compressed or exaggerated, so the music simply unfolds naturally without any need for embellishment.”
“Later, on ‘Lousiana Lowboat’, a different set of challenges arises, as we again hear Frisell’s guitar accompanied by drum kit and bass, but this time with the output of the guitar and bass channeled, in part, through electronics effects boxes. Thus, we hear the natural sound of the guitar and bass overlaid with effects that extend but also fundamentally alter the instruments’ natural voices. The inherent accuracy and clarity of (the system) makes it easy to tell exactly where natural instrumental timbres leave off and the effects-driven voicings begin. But there is also one further sonic challenge, as the bass drum and tom-toms on this track are very low pitched and tricky to reproduce well (indeed, the voice of the lowest drum is positively subterranean). Here, the (system) really shines as it wades right in and delivers shuddering, ultra low-frequency bass drum thwacks without skipping a beat, and while effortlessly capturing the skin sounds of both the bass and tom-tom drum heads.”
Now obviously these comments are partly a testimonial to the quality of the associated source and playback components I was using, but they are also very much a reflection of the absolute, bedrock solidity of the Burson HA-160. It’s a very powerful tool for anyone reviewing headphones or desktop audio equipment, because it has an almost uncanny ability to help ancillary equipment give of its best.
I also used the Burson quite extensively in working on my review for the exceedingly revealing (and extremely power-hungry) HiFiMAN HE-6 planar magnetic headphones. Let me refer back to some of the comments I made in the HiFiMAN review, which also serve to highlight particular strengths of the Burson amp. I wrote:
“I’ve spoken, above, about the (system’s) superior bass extension and pitch definition, and of (its) terrific transparency and finesse. To experience all of these qualities in play within one gorgeous track, listen to the Jim Brock Ensemble perform “O Vazio” from the Reference Recording’s Jazz Kaleidoscope [HDCD]. The track opens with a variety of percussion sounds produced by various sizes of gongs, chimes and drums--some high-pitched and quite delicate, others low-pitched and capable of abrupt, sharp-edged transient attacks. Finally, as the track unfolds, an enormous, ultra low-pitched drum is struck, filling the whole soundstage with deep, shuddering columns of air.
“The (system navigated) this demanding material with surprising ease and grace, making the chimes and higher-pitched gongs jump and shimmer with the wonderfully realistic sound of metallic instruments being struck and left to resonate in open space, while also capturing the depth, power, and weight of the low frequency instruments. In particular, the (system) captured the fast-rising pressure waves of the bass percussion instruments, so that I could actually feel the pressure gradient change within and around my ears…”
“There are also qualities of effortless suppleness and fluidity in the (system’s) presentation… To appreciate what I mean, let’s look at the track “Nothin’ To Do Blues” as recorded by the Mike Garson Quartet [again from Jazz Kaleidoscope]. The track opens with a bouncy, syncopated piano line played by Garson—a line that is quickly taken up by master bassist Brian Bromberg, who keeps pace with Garson note-for-note. In the background, you can hear percussionist Billy Mintz softly keeping time, gently working his brushes on the surface of his snare drum head. Even further in the background you can hear fellow band members start to groove on the lines Garson and Bromberg are crafting, urging the players onward with murmured words of appreciation and encouragement. As the song develops, Garson shifts gears to take an extended solo where the entire tone and tenor of his piano shifts, taking on a faster paced, smoother and more exploratory quality, almost like the sound of water rushing over the twists and turns of a stream bed. Later, Garson pulls back to give Bromberg a turn and he responds with a brilliantly agile, angular bass solo that probes the upper registers of the instrument.”
“At moments like these in great jazz recordings, where creative energy is on the boil, some (systems) try but fail to keep pace with the musicians and the sheer, delicious complexity of the sounds they are producing… Because (the Burson-powered system had) ample reserves of transient speed and timbral control to draw upon, (it was) able to track with the music, measure-for-measure, note-for-note, and nuance-for-nuance.”
The point I hope to convey, here, is that the Burson HA-160 is a very special amplifier, one whose excellence and fundamental musical honesty I have come to trust and rely upon.
Burson’s Audio’s HA-160 is a superb-sounding and incredibly well made headphone amplifier that is more than reasonably priced at $695. For headphone enthusiasts serious about pursuing top-tier sound, the search can begin right here—and for many, I suspect, it will also end here (because the Burson offers such terrific value for money that searching for something better is apt to become a very expensive proposition). Highly recommended.
SPECS & PRICING
Burson Audio HA-160 Solid-State Headphone Amplifier
Frequency Response: 5Hz (-0.3db) -35 kHz (- 1dB)
THD: <0.001% @ 6mW/300 Ohms
Analog Inputs: one stereo analog (via gold-plated RCA jacks with Teflon insulators)
Analog Outputs: two ¼” phone jacks (one “headphone out” optimized for lower impedance loads, one “line out” for higher impedance loads)
Input Impedance: 47 kOhm
Output Impedance: “headphone out,” 5 Ohms:“line out,” 60 Ohms
Headphone Power Output: 650mW @ 300 Ohms, 800mW @ 60 Ohms
Dimensions (H x W x D): 1.7” x 4.3” x 11”
Weight: 13.2 lbs.