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This is the 21st in a series of reviews dedicated to the concept of 32Ohm Audio as embodied by the store of that name in downtown Portland/Oregon and described here - Ed.


Contributor: Trinanjan Bhanja
Source:  Cambridge Audio Azur 640C 2.0 CD player
Interconnect: DiMarzio High-Definition RCA interconnects
Headphone Amplifier: Burson Audio HA-160
Headphones: AKG K702


Burson Audio is an emerging Australian company, which designs and manufactures high-end audio gear. In a thoroughly competitive market where there is no dearth of choice when it comes to audio components, Burson's designers claim to build their offerings using innovative technologies. A classic example is their Headphone Amp 160 or HA-160.


Built upon a fully discrete design, the HA-160 is entirely devoid of integrated circuits. Burson says that IC chips are poor building blocks for audio amplifiers. However, most headphone amplifiers contain operational amplifiers or ICs. So, does this discrete design translate to any added sonic goodness? I shall investigate by pairing the HA-160 with my AKG K702 headphones.

Burn-in: The Burson is fairly fresh in my stable. A lot of audiophiles suggest that one should cook or burn in components to improve their performance. However, the Indian summer is one hell of a cooker and running a Class A amplifier 24/7 is sure to trigger thermal meltdown. I prefer to burn in the Burson and AKG duo on my head as I listen to music, a few hours at a time.


About the AKG K702: I am not new to my K702 phones. Previously I used to drive them with a Headroom Ultra Micro. That was a supposedly evil design based on IC chips. But, the Headroom was far from bad. It was certainly a very good amplifier in its own right and powered the K702 fairly well. However, I observed a few shortcomings in the AKG and Ultra Micro pairing. The Burson fails to obliterate those flaws entirely. But it does lessen them which makes the overall sound more enjoyable than before.


This brings me to certain sonic traits of the AKG headphones.The K702 is a nice headphone, having a fairly large soundstage, excellent bass control, spot-on timing and bags of resolution. However, it also has a slight emphasis in the upper midrange relative to the midrange. This means that female vocals sound very nice but woodwinds at times less so. The Burson helps the K702 in this area and makes the midrange a bit more prominent yet falls short of eliminating the problem entirely. I shall discuss this at length later. Let us focus on the positive aspects of the HA-160 first and highlight the areas where it trounces the Ultra Micro.
Dynamics - The Burson advantage: The first thing you notice is that the Burson has more effortless dynamics than the Headroom. In Kyung Wha Chung’s rendition of Max Bruch’s Violin Concerto N°. 1, things get really loud in the interval from 05:10 to 06:30 in the opening "Allegro" and during 06:00 to 06:20 in the following "Adagio". Here my Ultra Micro had always sounded a bit strained and congested. The little Headroom seemed to overload with information and struggled to organize and render all instruments distinctly and coherently. During those frenzied orchestral peaks, the various instrumental layers would run into each other and the louder bits would yell with harrowed voices. I would turn it up in an attempt to enhance clarity but it would simply get louder, not clearer. Luckily the Burson sounds relatively effortless. Dynamic peaks are unstrained and musical and there is no sign of the amplifier overloading with musical information. The rendition is simply more organized and has better stereo imaging. Instruments are better separated and it is easier to hear everything at a lower volume. My ears feel blessed. Thank you Burson!


Timing: Another forté of the Australian and Austrian pairing is timing. Music just abounds with spirited rhythm and drive. In Anne Sophie Mutter’s rendition of Beethoven’s Spring Sonata, the "Scherzo" is portrayed with cheerful rhythm, my toes tapping in approval. The start and stop of every piano note are delivered with precision and inner detail and timbre carefully preserved. The AKG is simply a master at rendering the piano. I have listened to several high-end systems but seldom heard the variable damping of piano notes portrayed so convincingly.
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