“DiGiFi” magazine Vol.14

May 2014

JapanHeadphone Amplifier for Balanced Drive
Fascinated by High S/N Ratio and Overwhelming Drive Power
Text by Yoshio Obara
The new Headphone amplifier, just launched by Aurorasound,
has an aluminum chassis encased in a wooden cabinet, which
creates an aura of mid-century-like old-timer. The new model isHEADA.
The most noteworthy characteristic of HEADA is that theamplifier’s circuit is designed with balanced BTL architecture
enabling a powerful drive of even low-impedance headphones.
In order to maximize the benefits of the balanced BTL, it isequipped with balance-type headphone output terminals
accommodating 4-pin XLR or two 3-pin XLRs. The fact that
Aurorasound offers a service of modifying to 4-pin XLR indicates
how serious the company is with this particular feature. (Themodels having exchangeable cables, L & R will become
symmetrical configuration. A list of adoptable models will be announced in the company’s
homepage soon) It should be noted that an output terminal for unbalanced standard
headphones is also provided, therefore, users can fully enjoy superb performance and benefitsof HEADA.
The pre-amplifier stage is of a discrete circuit design with use of transistors and FETs. It has 4“Aurora Amp Module” units . These modules are energized by a power supply with a toroidal
power transformer coupled with low noise/low impedance regulator. There are two inputs, oneof which is balanced/unbalanced. The output is of throughout, therefore, it does not permit touse as a preamplifier. However, it is feasible to use this model with an external pre-mainamplifier.
Functionality is excellent. HEADA’s design philosophy is to accommodate any type ofheadphones by featuring not only an input selector, but also a high/low gain control. HEADA’sprecision design can be recognized by machine-tooled RCA jacks with rhodium-plated, XLR
output terminals manufactured by Neutrik, and solid metal insulators. The design ismeticulously detail oriented.
The first listening evaluation was done by connecting Ultrazone Edition8 to the standard plug.
Output from the CD player was plugged into INPUT-1 (balanced connection) and Gain Control
was set at LOW position. The combination of a large conductive-type potentiometer withaluminum knob transmits a high-quality feeling to users’ fingers when adjusting volume level.

The immediate
impression is that a highS/N and super high drive
give dynamic power.
Information content isextremely high which, nodoubt, will appeal andsatisfy audiophile-level
listeners. With confidence,
I can comfortably say thatHEADA is a rare breed
having well-balanced
pyramid-type energy
distribution, yet offers very
stable performance.
The sound using INPUT-2 had a little bit of boost in the low frequency range, however, just as
INPUT-1, resolution and wide dynamic range were excellent.
A listening evaluation was also conducted using SHURE SRH1840, an open-type headphone,which was modified for 4-pin XLR cable. The impression I got was that the characteristic of thisheadphone was enhanced. More specifically, it was a big surprise to me as the stereo image
widened and sound stage got expanded. I would say that the grade of this headphone waselevated by precision and fulfilling sound. The most impressive was that when I listened toTchaikovsky’s Symphony No.6 (Pathetique), which was performed by Leningrader Orchestra
conducted by Mravinsky. I was able to hear delicate passages with fine details and harmony
together with each instrument’s smooth, yet precision sound out of SACD.
As noted at the beginning, since the cosmetic design is very unique and somewhat classicstyle, it may not blend well with today’s high-tech audio equipment. However, those who arelooking for a headphone amplifier for serious indoor listening, HEADA is an attractive choice.