Acurus A2002 - Page 18

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A 2 0 0 0 - S E R I E S A M P L I F I E R U S E R G U I D E
©2012 Indy Audio Labs, LLC all rights reserved / Revision20120420
Document No. 1000571
design notes
The Acurus A2000 series was designed by engineers
at Indy Audio Labs to deliver audio experiences un-
matched by any other products in their category.
While not an easy task, here’s how we do it.
To achieve such a high level of perfection in a high-
performance audio amplier, a reliable, fast, efcient
amplier topology is required. The Acurus A2000 series
uses high-bandwidth, matched On Semiconductor®
output transistors in a fully-discrete class A/B design,
input-to-output. Unlike many other discrete topologies
in this class of amplier, our design remains symmetric
from the very rst current-mirror input stage on through
to the output. No op-amps are used in the signal path
- only precision, low-noise semiconductors. The result
is an audio output that nearly perfectly mirrors the input
signal characteristics and dynamics. Soundstage is dis-
tinct, broad and detailed. High-frequency transients are
crisp and clean. Bandwidth is beyond wide, spanning
from less than 10Hz on the low end to more than 70 kHz
at the top, well beyond the range of most sources, let
alone human hearing. Low-frequencies are reproduced
authoritatively due in no small part to the big power
supply which features a massive toroidal transformer
and 46,000 microfarads of power supply capacity even
in the basic A2002. The 5 and 7-channel models more
than double that capacitance. In fact, all A2000 series
ampliers are capable of delivering current peaks to a
speaker load exceeding 18 Amps!
However, we don’t feel it’s not enough for engineers to
build a unit which measures well on the test bench. To
make every one of these ampliers sound as good in
your home as the very rst ones we hand-built in the
lab, we have the circuit boards stuffed and inspected by
both hand and machine and nal assemble each here
in the USA in our factory in southern Indiana. We take
advantage of a manufacturing environment designed
to make not only high-performance audio products, but
also precision devices for demanding medical, military
and communications customers. Within our products,
carefully inspected printed circuit boards feature thick
copper layers and are populated with tight-tolerance
(1%) resistors and lm capacitors throughout the signal
path. Internal wiring is done by hand using high-tem-
perature and Teon-coated materials. Transformers are
custom-wound to our specications and made in North
America with virgin materials.
The solid look of these ampliers should come as no
surprise. The Acurus A2000 series metalwork is done
right in Indiana at some of the same precision metal
suppliers building certied componentry for IRL (Indy
Racing League) cars. Thick-gauge steel forms the
framework for the Acurus-standard anodized Aluminum
alloy faceplate, top cover and side heat sinks. The frame
is powder-coated white to protect it, to make assembly
easier and to make the rear panel easier to read during
installation in the typical dimly-lit home AV equipment
rack. Unlike most of our competitors, externally mounted
heat sinks on all models draw heat away from the interior
of the chassis using natural convection most effectively,
especially in a rack mount scenario. Custom rack ears
make system-integration smooth. Mechanical details
are important to us - down to the laser-etched logo and
model information on the custom-tooled front panel.
Even the power switch was designed from the ground-
up by Acurus engineers for long-life, good illumination
and a solid feel.
When an Acurus amp initially “comes to life” on the as-
sembly line, we make sure it’s rst days are its most dif-
cult. Once an amplier is fully-assembled and quality-
checked, it is tuned on the assembly line for optimal
performance prior to burn-in, tested and then re-tested
once again. Our tough burn-in tests not only prepare the
amplier for rst use but also expose it to worst-case op-
erational loads, exceeding the most challenging home
environments we can imagine. Our goal is to make sure
each amplier we build lasts as long as legacy Acurus
amps built more than a decade ago.
While we’re proud of what we achieved with the Acurus
A2000 series, we recognize our own human bias can
easily get in the way of objectivity and fair comparisons.
That’s why we chose to engage the assistance of THX to
certify our Acurus A2000 series to their stringent Ultra2
requirements. THX Ultra2 is designed for home audio
enthusiasts that demand peak performance. It offers