Burson Audio HA-160

No-nonsense purist design that can accommodate a wide range of headphones.
 

[size=large]Introduction[/size]
Burson Audio Melbourne, or Team Burson as they’re affectionately known, don’t seem to like integrated circuits much. As a matter of fact, they’ve published an extensive article on their website as to why integrated circuits suck and are only used by dodgy manufacturers that want to cut down production costs. Surprisingly however, their argument against little bits of silicon doesn’t take the predictable and well-worn track back to the glowing triodes of audiophile antiquity. Enter the HA160, based on the Burson discrete HD opamp and their answer to the travesties of IC-based amplification.

I can make no comment as to the validity of these claims. I’m nowhere near technically savvy enough to be able to tell the difference between good engineering and just good marketing. But having owned an M3 in the past, I can attest to the frustration involved in dealing with those little wafers of six-legged arbitrariness. Want a full, present midrange? Be prepared to give up your frequency extension at each end. Want a linear response across the board? Brace yourself for listener fatigue and sibilance. It quickly becomes a game of picking the lesser evil, and the search for “one opamp to rule them all” ultimately proves too much of a distraction from what’s important, the music.

So when I heard about a Melbourne company producing a new all-discrete headphone amplifier, capable of putting 650mW of class-A goodness through my beloved Sennheisers, I was immediately interested. A few emails to John later, and I had a review sample on its way.

[size=large]Build quality, functionality and usability[/size]
The HA160 arrived in a Burson-branded white cardboard box, inside which was fitted Styrofoam inserts to protect the amplifier from the destructive forces of Australia Post. Also included was a user manual, power cord, plastic covering and the biggest satchel of silica gel I’ve ever seen. I almost pity the moisture that tries to work its way into this box. Stay tuned for my next review where I test the silica as an umbrella replacement under heavy rainfall.

The amplifier itself is a fairly spartan silver box, marked with the Burson Audio logo, a large volume knob and two sets of ¼” headphone jacks on the front panel. Neither jack has any markings to differentiate them, but the manual explains one to be optimised for low impedance (15-150 Ohm) and the other for high (150-500 Ohm). It’s interesting that they only recommend up to 500 Ohms for the high impedance jack, which is bound to raise doubts in the minds of Beyerdynamic owners considering the HA160.

The rear panel features only a single set of RCA inputs, an IEC power inlet, and a display showing what voltage the amplifier has been set to. To all those who like source selector switches, multiple inputs, preamp outputs and other such functionality, prepare to be disappointed. Although the lack of such paraphernalia makes a statement of its own – the HA160 was designed to do one thing, and do it well.

Last but not least, the stepped attenuator. This has been my main cause for contention since receiving the HA160. With the HD800 plugged into the high impedance jack, I have 5 steps of usable volume range. That leaves 19 steps useless, and makes finding the optimal listening volume quite difficult. A further cause for worry is that as one turns the knob, volume increases before the attenuator has actually reached the next step. It “cuts in” somewhere between steps, and occasionally does so only in one channel. Step 7 on my attenuator actually seems to be mono – not that I would listen at that level for any sustained period anyway, but such inconsistencies trouble me when putting an amplifier through its paces.

[size=large]Test setup[/size]
The HA160 was burned in for 100hrs prior to critical listening, and used in the following setup:
Foobar configured for WASAPI bit-perfect output, playing FLAC > HeadAmp Pico DAC > Burson HA160 > Sennheiser HD800 with stock cable.



[size=large]Listening Impressions[/size]
I start the gamut of listening impressions, as all good reviewers should, with Shpongle. The fast paced and complex electronica of Dorset Perception proved to be no challenge for the HA160, coping with layer upon layer of psychadelica with startling finesse. I might or might not have invented a new word there.



One gladiator successfully defeated, the HA160’s next opponent comes in the form of Tool’s Reflection, a test of bass texture and imaging. The HA160 began to show a few weaknesses here, glossing over some of the finer details and resonance in this track. Reverberation from the drums didn’t carry quite as far as it should, adding a slight unrealism to their portrayal. On the flip side, cymbal strikes shimmered spectacularly, creating vivid pinpricks of colour amidst the unrelenting darkness of this track.



Following on the theme of bassy and atmospheric, next up is Enigma’s Gravity of Love. This track features a deep, subterranean rumble that the HA160 rendered faithfully, juxtaposed against the crystalline tinkling of a triangle above. Again though, there seems to be less sense of space in this track than normal, as if the decay of notes is being cut prematurely short. Not by much, mind, but with such a clear window into the music as the HD800 on your noggin, any compression of airiness is difficult to miss.



Now it’s time to mix it up a bit, with Michael Jackson’s Don’t Stop Till You Get Enough. The HA160 breathed an almost audible sigh of relief, and then proceeded to inundate my ear canals with fast-paced pop. It seems that dynamic attack-oriented music is where the HA160 is most comfortable, and it certainly had no troubles whatsoever with the rendition of this track.



No aussie review, of aussie equipment, would be complete without some aussie music. Introducing Mr Bruce Mathiske’s 23 Hours In Geneva, a slowly building acoustic guitar instrumental. Having had the pleasure of hearing Bruce perform this track live in the past, all I can say of the HA160 > HD800 combo was that it recreated that experience. I can close my eyes and be back in my seat in the theatre, about 4 rows up from Bruce, as he tells a story with that one instrument.



Last but not least, we have Loreena McKennitt in Dante’s Prayer, as a test of female vocals. This is one of those musical experiences where no matter what you were doing before, as soon as Loreena begins singing all distractions fall away before the glory of her voice. This track seems to have been recorded in a church or cathedral, and it shows as Loreena’s voice reaches for the sky and finds no barriers. None imposed by the recording venue, nor by the amp’s limitations. The lovely shimmering of cymbals noted in previous tracks seemed to be hinting at something that Loreena has now revealed clearly – the HA160 excels at treble extension and sparkle.



[size=large]Conclusion[/size]
“Burson sounds good, like a solid state should!”
The Burson marketing slogan is, if anything, an understatement. The HA160 conveys a startling level of conviction for an amp at its price point, the overall impression being one of authority. Compared to truly world-class solid state amps like the Beta22, the HA160 keeps up in most ways. It portrays vocals, and particularly female vocals with palpable vividness, and handles complex passages of music admirably.

It only begins to struggle with tracks requiring a large sense of space and atmospheric reverberation, sounding comparatively closed in. The stepped attenuator is a worry as well, both in terms of minor glitches and lack of usable range. But all in all, I have no qualms recommending the HA160 as an incredible sounding amplifier in the sub-$1k price bracket.

[size=large]Recent Updates[/size]
Since posting this review I've sent the demo HA160 back to Burson, and they have identified a mechanical fault with the stepped attenuator that was causing the issues at step 7, as well as the distortion/imbalances as the knob was being turned. They've assured me they'll be tightening their QC processes and packing methods to eliminate this problem in the future.

I've also bought my own brand new HA160, which as I hoped exhibits none of the issues with the stepped attenuator that the demo unit did. Additionally, an error in Burson's user manual has come to my attention - the manual has the two headphone outputs reversed, and what I thought to be the low impedance jack was actually the high, and vice versa.

Which dispels my initial concerns that low impedance, efficient headphones would simply be unusable with the HA160. I tried a JVC DX1000 through what I thought was the low impedance jack on the demo unit and only got 2 steps of range, but I now know this to be because I had the jacks reversed. The DX1000, which is 64 Ohm and quite efficient at 102dB/mW now gets 5 steps of range, which is enough to be usable.

Burson have assured me I can use the low impedance jack for headphones higher than 150 Ohm with no loss of SQ as well, which is a good thing considering that the high impedance jack has far too much gain for Sennheisers. Maybe 600 Ohm beyers will suit that jack better. But regardless, my issues concerning the attenuator are largely resolved with the arrival of my new unit.

Advanced and quality build.