Krell Industries Evolution Quick start guide

OWNER’S REFERENCE
EVOLUTION ONE
MONAURAL POWER AMPLIFIER
EVOLUTION

Evolution One Monaural Power Amplifier Owner’s Reference, v05.0
Krell Industries, Inc.
45 Connair Road
Orange, CT 06477-3650 USA
TEL [phone]
FAX [phone]
E-MAIL [e-mail]
WEBSITE http://www.krellonline.com
This product complies with the EMC directive (89/336/EEC) and the low-voltage directive
(73/23/EEC).
WARNINGS
The amplifier must be placed on a firm, level surface where it is not exposed to dripping or splash-
ing.
The ventilation grids on the top of the amplifier and the space underneath the amplifier must be
unobstructed at all times during operation. Do not place flammable material above or beneath the
amplifier.
Before making connections to the amplifier, ensure that the back panel power switch is down.
Make sure all cable terminations are of the highest quality, free from frayed ends, short circuits,
or cold solder joints.
The differential circuitry employed with an Evolution One Monaural Power Amplifier requires special
attention when connecting speakers. Do not connect the negative speaker terminals together. Do
not connect the negative speaker terminals to ground.
Do not connect an Evolution One Monaural Power Amplifier to a loudspeaker selector device that
employs a common ground scheme, as it may short-circuit the amplifier output.
THERE ARE NO USER SERVICEABLE PARTS INSIDE AN EVOLUTION ONE MONAURAL POWER
AMPLIFIER.
Please contact Krell if you have questions not addressed in this guide.
This product is manufactured in the United States of America. Krell®is a registered trademark of Krell Industries, Inc., and is restricted for use
by Krell Industries, Inc., its subsidiaries, and authorized agents. Evolution Bias™ is a trademark of Krell Industries, Inc. and is a Krell technology
based on U.S. Patent No. 5,331,291. CAST™, Evolution CAST™, and Krell Current Mode™ are trademarks of Krell Industries, Inc. All other
trademarks are registered to their respective companies.
© 2005 by Krell Industries, Inc. All rights reserved P/N 307772

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iii
Contents
List of Illustrations, page iv
A Letter from Dan D’Agostino, page 1
SECTION ONE: About Krell, page 3
The Krell Legacy, Revolutionary Krell CAST Technology,
Ensuring Maximum Performance, and Definition of Terms
SECTION TWO: Unpacking and Placement, page 12
Opening the Evolution One Shipping Cartons
SECTION THREE: Anatomy of an Amplifier, page 15
Features and Benefits of the Evolution One Design
SECTION FOUR: Connecting an Evolution One Amplifier to Your System, page 19
CAST and Voltage Connections, Connection Steps,
DC Protection Circuitry, and Remote Control Options
SECTION FIVE: Amplifier Operation, page 22
Powering Up, Adjusting Power Meter Modes,
Switching between CAST and Voltage Connections,
Amplifier Care
SECTION SIX: Amplifier Troubleshooting, page 26
WARRANTY, page 28
RETURN AUTHORIZATION PROCEDURE, page 30
SPECIFICATIONS, page 31

iv
List of Illustrations
Figure 1, page 15
Evolution One Amplifier and
Power Supply Chassis Front Panels
Inset Evolution One Amplifier Channel: Front Panel View
Figure 2, page 16
Evolution One Amplifier and
Power Supply Chassis Back Panels
Figure 3, page 17
Evolution One Amplifier Chassis Top
Figure 4, page 18
Evolution One Power Supply Chassis Top

continued
A Letter from Dan D’Agostino
Dear Audio Enthusiast,
Thank you for your purchase of the Evolution One.
The Evolution One Monaural Power Amplifier represents a watershed in my design
philosophy and in my quest for amplifiers that deliver absolute truth in music
reproduction. This new amplifier operates solely in the current domain, with only
one voltage gain stage at its output. I have always been fascinated by the artistry
inherent in great musical performances, and I believe that no component in an
audio system equates more closely to the full range of musical expression than
the power amplifier. The Evolution One reproduces real-life dynamics and trans-
parency in a manner that I have not experienced prior to this design. It is my
pleasure to make it available to you.
Krell amplifiers are best known for their ability to drive any loudspeaker to sound
its best, without regard to impedance or efficiency. The Evolution One amplifier
joins this awesome current capability with a new, ultra-linear circuit topology. It is a
strong belief of mine that linearity, an amplifier’s ability to output an exact dupli-
cate of the input signal, is the ultimate measure of that amplifiers worth. I drive
Krell amplifier designs toward the common goal of linearity; through the rigorous
application of Krell design principles that focus our efforts on four major perform-
ance factors: distortion, bandwidth, output impedance and current capability. The
Evolution One excels in each of these areas, delivering absolute accuracy from
extremely low levels of output, virtually at preamplifier levels, to astounding, awe-
inspiring amounts of power.
As the foundation of my new Evolution Series, the Evolution One Monaural Power
Amplifier is designed to complement the Evolution Two Monaural Power
Preamplifier perfectly. Combine the Evolution One and Two with my new LAT-1000
loudspeakers, and experience the extraordinary capabilities of the Evolution
System.
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I have some exciting news for you. Work on a new source component for the
Evolution Series is ongoing as of this writing. Possessed of the unique Evolution
technologies that power the amplifier and preamplifier, this Evolution source will
expose the real advantages of the latest recording formats while taking compact
disc playback to the next level. I encourage you to audition it as soon as it is
released.
Sincerely,
Daniel D’Agostino
Chief Executive Officer
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(A Letter from Dan D’Agostino continued)

continued
SECTION ONE
About Krell
This section describes the Krell Legacy, innovative Krell amplifier design and technol-
ogy, and defines key terms used in this reference.
The Krell Legacy
“I design every Krell component to set the standard
for workmanship, style, and performance.”
Dan D’Agostino
High-end audio is a demanding pursuit—an ongoing quest for excellence in
music reproduction that drives equipment manufacturers to strive for the absolute
in design and performance. With a keen understanding of this passionate drive,
Krell Industries, Inc., was founded in 1980.
Over the past 2-1/2 decades, Krell has earned a distinguished reputation for engi-
neering innovation and product excellence. The company’s history is replete with
product introductions that have deeply impacted the high-end audio industry.
The most discriminating audiophiles and product reviewers have consistently
recognized Krell components for standard-setting performance.
The Evolution One amplifier brings Krell design to a new level, setting a standard for
performance that will not soon be matched. The shear breadth of this amplifier’s
dynamic range capabilities conveys a startling realism that transcends previous
designs. Seemingly unlimited frequency response, combined with unerring accu-
racy and fortitude, extend a tradition that began with the first Krell amplifier — the
KSA-100.
The KSA–100 was the first high-power, high-current, true Class A biased stereo
power amplifier available to audiophiles. It was the first Krell product, and its
resounding success established Krell as an important new technological contrib-
utor to high-end audio.
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From the KSA–100 to the present, Krell C.E.O. Dan D’Agostino has continually
“pushed the envelope” of performance in his search for greater amplifier power.
His exploration of new technologies, driven by his never-ending quest to elevate
the standard of excellence, has resulted in breakthrough audio designs. Over the
years, the Krell line of power amplifiers, including benchmark products such as the
KRS–100, KRS–200, and the Audio Standard models, has established a legacy of
unparalleled sonic performance.
The Krell product line has diversified, but Dan’s fundamental research into amplifier
design and performance remains at the core of the company’s achievements. Every
Krell component upholds the legacy, incorporating unique technologies that are the
direct result of Dan’s discoveries in audio amplification.
The Evolution One amplifiers build on the Krell legacy. They provide unprecedent-
ed linearity with the control and accuracy that only comes from superior current
capability. The sound is lively and unconstrained, in a manner that evokes live per-
formance and the true sound of instruments.
Dan D’Agostino remains committed to the development of new designs and
technologies. And the Krell legacy will continue to evolve with products that deliver
innovative engineering, perfection in build quality, and outstanding audio performance.
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(SECTION ONE: About Krell continued)

continued
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Revolutionary Krell CAST Technology
Current Audio Signal Transmission, termed CAST, is a revolutionary method of con-
necting analog audio components for unparalleled sonic performance. Innovative
engineering combines the new Krell CAST circuitry with existing Krell Current Mode
technology to create entire CAST systems that reproduce music with incredible range,
tonality, and precision.
The Voltage Signal Transmission
and the Traditional Audio System
Traditionally, signal is transmitted in the voltage domain between two components.
In an audio system, each component is a discrete entity with unique characteristics
that act upon the musical signal independently. Each component is unaware of the
other components in the system. The cables that connect the components also
have their own electrical characteristics, which affect the sonic presentation of the
entire system. CAST transmission unifies individual components and interconnects
into an electrically linked whole. The original signal remains unaltered from source to
speaker.
CAST Basics
Here’s how a CAST audio system works. Internally, each CAST source transfers,
or amplifies, current using Krell Current Mode circuitry. This current signal is
then output using CAST circuitry. When the signal is received by a CAST input,
Krell Current Mode circuitry again takes over until the signal reaches the loud-
speaker. By maintaining the musical signal in the current domain from beginning
to end, an entire CAST system behaves as if it is one component. With CAST,
circuit board properties and signal transmission aberrations between compo-
nents are eliminated. Cable impedances and their effects on the transmitted sig-
nal are non-existent.
How CAST and Krell Current Mode Interact
While CAST is a new method of transferring the musical signal between compo-
nents, its origin stems from Krell Current Mode, the technology developed to
transfer the musical signal within a component. CAST combined with Krell Current
Mode takes circuitry signal transmission to the next evolutionary level. In essence,
Krell Current Mode maintains the integrity of the signal within the component and

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(How CAST and Krell Current Mode Interact continued)
CAST preserves the transmitted signal between components. Together, CAST and
Krell Current Mode technologies unify separate Krell components into a single
global circuit. Krell Current Mode technology enjoys bandwidth increases up to an
order of magnitude greater than their voltage based counterparts. This dramatic
increase in circuit bandwidth delivers near perfection in the audible band that typi-
cally suffers from phase distortions in voltage circuits.
CAST Cable Construction
A CAST system uses cables manufactured by Krell and other manufacturers spe-
cially licensed by Krell. Thin and flexible CAST cables are constructed with the
same build quality as other Krell components and are aesthetically matched to the
components that Krell manufactures. An all-metal body and locking connectors
with gold contacts are part of the standard no-compromise specification devel-
oped for every CAST cable made.
Evolution CAST
By employing radical current mirror circuitry, the Evolution components elevate the
CAST technology to another level. This advanced use of the technology increases
the linearity, transient speed, and bandwidth of the Evolution components while
reducing the distortion by an order of magnitude.
The Best Musical Performance
When you operate a CAST system, you will hear significant improvements in every
performance area: speed, precision, dynamic range, depth and width of the sound
stage, transient impact, tonal balance, harmonic distortion, and more. The goal for
CAST is the same company goal used for all Krell products. Krell strives for the
delivery of the best performance of a musical event for you, using the full expres-
sion of technology to date.
(SECTION ONE: About Krell continued)