Translating Technology

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Translating
Technology Performance and Reliability.
Without the Window Dressing. For more than three decades, designer/engineer Morris Kessler has created audio
products with a simple goal in mind: delivering maximum performance and reliability.
In his products, you will find no gratuitous features or needless ornamentation. But
everywhere you look, you will find design touches that improve sound quality and
increase dependability. Beginning in the 1960s with SAEone of the pioneers in high-quality solid-state
amplificationand extending into the new millennium with Amplifier Technologies, Inc.,
Kessler has always relied on proven designs. Most of his original products, some more
than three decades old, are still hard at work in consumers homes. Through the decades,
he has refined his circuits to near-perfection. And from the first day, he has operated his
own Southern California factoryunlike most audio companies, which subcontract their
vital manufacturing processes to anonymous offshore companies. In the following pages, you will see what makes ATI todays best value in home audio. AT2000 with
rack mount
option shown
actual size An Interview with Morris Kessler,
ATI Founder and Chief Engineer Is there an overall philosophy in the way you design and build products? In all the products Ive designedeven going back 30 years agothe focus is on value and
performance. ATI products arent inexpensive, but you always get your moneys worth.
Youre not buying a boxful of air. Whats filling all that space? Big heat sinks, for one thingwe could save space by using fans, but that creates a lot of
noise. Big transformers, and separate power supplies for each channel. We also ground all
of our amplifiers at a single, central point, instead of grounding them in the transformer.
That improves the grounding and lowers noise, but it means we have to have extra rectifiers in
the power supply. As a result, we create a weight issue, too. Heat sinks and big transformers are
heavy, so you need an extremely sturdy chassis to support them. We could save some cost by,
for example, using cooling fans, but the end product wouldnt be as good as I want it to be. You seem to take your design cues from Henry Fordall of your products come
in whatever color you want, as long as its black. People should get what they pay for. Using a faceplate that costs as much as the rest of the
amp costs doesnt make sense to me. An amps chassis should be sturdy and have a nice
design, and thats it. How do you assure that all of your
products achieve the quality
standards you set? Well, we manufacture or assemble
everything right here in our own factory.
I do have an office in the factory, but my
real office is out on the production line.
I spend a lot of time there making sure
everythings running right. How has ATI evolved over the years? Ive been manufacturing amplifiers for
decades. Around 93, I got interested in
computer-aided design [CAD], and built a
stereo amp just for fun. I got the bug again, and brought the amp to the 1993 Consumer Electronics Show to see if we could drum up
any interest. I ended up getting requests to build amps for other companies, and weve
since built amps for at least a half-dozen companies whose names you would definitely
recognize. In between those jobs, we started building ATI amps. The first ATI amps were
very successful, and weve expanded the line greatly from there. ATI Manufacturing:
No Shortcuts, No Compromises We assemble all ATI products in our 50,000-square-foot Southern California factory.
Everything is built 100 percent to our specifications, and we monitor every aspect of the
quality-control process ourselves. Here are some of the steps we take to make ATI products
the best value in the audio industry. All of these improvements pay off in dependability
and sound quality. Toroidal Transformers An amplifier starts with the power supply,
which starts with the transformerthe
source of an amplifiers power. We wind all
of our own transformers in our own shop, to
assure the highest quality. The transformer
cores in our amplifiers are made from
MOH, with magnetic properties that make
the cores 18 percent more efficient than
standard transformer cores. Each amplifier
channel gets its own set of windings, which
minimizes interaction between channels.
We wind the cores two wires at a time, a
technique called bifilar winding that
ensures perfectly symmetrical transformers that work more efficiently and produce less distortion. Our techniques and
materials combine to create the highest
quality power transformers in existence. Each amplifier channel gets not only its
own set of transformer windings, but its
own rectifier and storage capacitors, thus
giving each channel its own separate
power supply. Even if the left channel is
pushed to the limit by, say, a loud car crash
on a movie soundtrack, it does not affect
the power that the other channels receive. Enclosures We house our products in rugged chassis,
with powder-coated finishes that resist
scratches and prevent corrosion. Our
hardware is equally durable and rustproof, made from Teflon-coated, 18-8 stainless steel.
We use inserts instead of threading metal parts resulting in a stronger unitized chassis. 4 Bifilar transformer winding process Transformers produced in ATI factory We assure the quality behind the name Heat Sinks Because we design our amplifiers for the
home as well as the rigorous demands of
commercial applications, we use substantial
heat sinks for each channel. This results in
amplifiers that run absolutely quietly and
as coolly as possible. The result; there is no
noise to mar your listening experience and
your amplifier operates more efficiently
for a longer life. These over-size heat sinks
eliminate the need for fans that add noise
and introduce dust into the amplifier. Circuit Boards We use double-sided FR-4 glass epoxy circuit boards in all of our products. Not only does a double-sided board handle twice the
electrical current that a single-sided board does, it produces much more solid connections
to the components on the board. The solder joints that secure the components to the
board cover both surfaces of the board, plus the inside of the hole into which the
component leads are inserted. As a result, our circuit boards are practically perfect,
with nearly zero failures due to bad connections and cold solder joints. The components we use on our circuit boards also add to the quality of ATI products. All
of the gain stages in our products employ high-quality metal-film resistors with 1-percent
tolerances, to ensure that each and every circuit board functions exactly like the last. Wiring Open most multichannel power
amplifiers and you will see a rats
nestdozens of wires running
haphazardly through the chassis.
Open up an ATI amplifier, though,
and you will see a clean layout,
with wires wrapped neatly in a
fiberglass cloth tubing originally
developed for the aerospace
industry. The tubing protects the
wire from both heat and
accidental damage. Chassis-Mounted RCA Jacks The gold-plated RCA input jacks on our
amplifiers are mounted directly to the rear
panel, instead of to a circuit board. While
this technique complicates assembly, it
results in a more robust connection, and
the jack cannot be accidentally broken off
by the tight-gripping RCA plugs used on
many audiophile interconnect cables.
In addition, our AT2000 and AT3000 Series
power amplifiers use XLR-type connectors
to make connections with the balanced
audio output from a preamplifier such as
our ATP8500.1 with balanced audio outputs. Trouble-Free Circuit Breakers Our higher power multi-channel amplifiers use magnetic circuit breakers to protect against
AC overloads. If the breaker trips, its a simple matter to reset it. Most amplifiers, however,
use fuses for overload protection; if a fuse blows, you must have the proper one available
to restore power to your amplifier. Protection Circuits ATI amplifiers employ lightning-fast optically-coupled protection circuits that are
completely removed from the signal path so they cannot affect the sound quality. These
protection circuits are designed to detect electrical shorts in speakers or speaker wires
and to sense electrical
spikes. If triggered, the
circuit will disengage the
output. The protection circuit
will sample the affected
circuit every 10 seconds
and will restore output
automatically when safe to
do so. This special feature
minimizes the chance of
your amplifier going out of
service just when youve
filled your home theater
with expectant guests. 5 AT2000 circuit board with heat sink Fiberglass cloth tubing protects wires Rear panel chassis-mount RCA jacks Amplifiers on the assembly line Engineers, reviewers, and home theater enthusiasts
may often disagree, but when it comes to amplifiers, there is one fact on which they all find common ground: The best possible design is the fully differential balanced amplifier. A fully differential amplifier is basically two separate amplification circuits per channel. One circuit amplifies the positive half of the audio signal, while the other amplifies the negative half. The benefits of this design are tremendous. It automatically rejects any noise coming in from external sources, such as radio-frequency and electromagnetic interference. It eliminates hum and reduces distortion. It also doubles the slew rate (speed) of the amplifier, for better reproduction of high frequencies, and better transient performance. We call this technology Pure Balance

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