Krell Industries EVOLUTION 202 User Manual
EVOLUTION
THE LEADER IN AUDIO ENGINEERING
OWNER’S REFERENCE
EVOLUTION
EVOLUTION 202
STEREO PREAMPLIFIER
THE LEADER IN AUDIO ENGINEERING
EVOLUTION 202
STEREO PREAMPLIFIER
OWNER’S REFERENCE
Evolution 202 Stereo Preamplifier
Owner’s Reference, v06.0
TEL 203-298-4000
Krell Industries, Inc.
45 Connair Road
Orange, CT 06477-3650 USA
FAX 203-891-2028
E-MAIL sales@krellonline.com
WEBSITE http://www.krellonline.com
This product complies with the EMC directive (89/336/EEC) and the low-voltage directive
(73/23/EEC).
IMPORTANT SAFETY INSTRUCTIONS
1. Read Instructions.
2. Keep these Instructions.
3. Heed all Warnings.
4. Follow all Instructions.
5. Do not use this apparatus near water.
6. Clean only with dry cloth.
7. Do not install near any heat sources such as radiators, heat registers, stoves, or other appa-
ratus (including amplifiers) that produce heat.
8. Unplug this apparatus during lightning storms or when unused for long periods of time.
9. Refer all servicing to qualified service personnel. Servicing is required when the apparatus
has been damaged in any way, such as a power-supply cord or plug is damaged, liquid has
been spilled or objects have fallen into the apparatus, the apparatus has been exposed to
rain or moisture, does not operate normally, or has been dropped.
10. The Evolution 202 preamplifier must be placed on a firm, level surface where it is not exposed
to dripping or splashing.
11. The ventilation grids on the top of the Evolution 202 preamplifier and the space underneath the
Evolution 202 preamplifier must be unobstructed at all times during operation. Do not place
flammable material above or beneath the preamplifier.
12. Before making connections to the Evolution 202 preamplifier, ensure that the power is off and
other components are in mute or stand-by mode. Make sure all cable terminations are of the
highest quality, free from frayed ends, short circuits, or cold solder joints.
13. Do not connect an RS-232 cable to the phono power port. Output from the phono power port
can seriously damage your computer.
14. Do not connect the cable from a Krell KPE phono stage to the RS-232 port.
15. THERE ARE NO USER SERVICEABLE PARTS INSIDE AN EVOLUTION 202 PREAMPLIFIER.
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
based on U.S. Patent No. 5,331,291. CAN Link
Inc. All other trademarks are registered to their respective companies.
© 2006 by Krell Industries, Inc. All rights reserved P/N 309158W
™, CAST™, Evolution CAST™, and Krell Current Mode™ are trademarks of Krell Industries,
™ is a trademark of Krell Industries, Inc. and is a Krell technology
Contents
List of Illustrations, page 4
A Letter from Dan D’Agostino, page 5
SECTION ONE: Evolution 202 Features and Technology, page 6
Features, Revolutionary Krell CAST Technology,
Definition of Terms
SECTION TWO: Unpacking and Placement, page 11
Opening the Evolution 202 Shipping Carton
SECTION THREE: Quick Start, page 13
Connecting the Evolution 202 to Your System,
Operating the Evolution 202
SECTION FOUR: Anatomy of the Evolution 202, page 15
Front Panel Description, Remote Control Description,
Battery Installation, and Back Panel Description
SECTION FIVE: Connecting the Evolution 202 to Your System, page 26
Input and Output Connections, Connection Steps
SECTION SIX: Evolution 202 Operation, page 28
On/Off and Stand-by Operation
SECTION SEVEN: Customizing the Evolution 202, page 29
Navigation Conventions, Menu Functions
SECTION EIGHT: Troubleshooting System Noise, page 43
WARRANTY, page 44
RETURN AUTHORIZATION PROCEDURE, page 46
SPECIFICATIONS, page 47
3
List of Illustrations
Figure 1, page 15
Evolution 202 Preamplifier and Power Supply Front Panels
Inset Preamplifier and Power Supply Stacked View
Figure 2, page 19
Evolution 202 Remote Control
Figure 3, page 22
Evolution 202 Preamplifier and Power Supply Back Panels
4
A Letter from Dan D’Agostino
Dear Audio Enthusiast,
Thank you for your purchase of the Krell Evolution 202 preamplifier.
The preamplifier plays a vital role in audio playback by mediating the line-level out-
put of a wide variety of source components in preparation for the amplifier’s input.
At no other point in the reproduction process is music so vulnerable to change, as
the signal level is small, and susceptible to noise and distortion.
Having always valued the role of the preamplifier in fine audio systems, I take preamplifier design very seriously. I realize that, no matter how impressive an amplifier’s performance; it can be no better than that of the preamplifier driving it.
My new Evolution 202 preamplifier employs a powerful, separate power supply,
Krell Current Mode gain stages from input to output, and Current Audio Signal
Transmission (CAST) receivers and transmitters. Utilizing these powerful technologies, the Evolution 202 conveys the complete range of timbre and dynamics that
comprise the foundation musical performance. Typical of my latest preamplifier
designs, the Evolution 202 preamplifier includes a thoughtful suite of menu
options and can be customized for the greatest ease of operation.
I hope that you enjoy your new Evolution 202 preamplifier.
Sincerely,
Daniel D’Agostino
Chief Executive Officer
5
SECTION ONE
Evolution 202 Features and Technology
This section describes the innovative features and technology of the Evolution 202
preamplifier, and defines CAST and other key terms used in this reference.
The Evolution 202 Stereo Preamplifier, evolving from the flagship Evolution Two,
works to carefully transmit audio signals without damaging the ephemeral staging
and dimensional components of the music. The Evolution 202 is a two chassis
design with a separate power supply that isolates the critical audio stages for the
lowest possible noise floor. A combination of advanced technologies and inspired
design elevate the Evolution 202 preamplifier’s performance to the reference level.
Features
Preamplifier
The Evolution 202 has a 1 MHz open loop bandwidth in a zero feedback, balanced Krell Current Mode design, terminating in Evolution CAST ™. CAST inputs
and outputs drive a newly designed current mode balanced input stage. Class A,
balanced circuitry is used throughout. Cascoded, current mirror input and output
stages utilize an LED voltage reference to achieve an exceptionally linear state of
operation.
There is no feedback employed anywhere in the design. A digitally controlled, analog volume control is accomplished entirely in the current domain. The bandwidth
and transient response through this circuit is virtually unaffected by the volume
setting. A new, Krell-designed digital control circuit monitors and optimizes the
preamplifier’s operating parameters.
Power Supply
The separate power supply makes extensive use of electrical and magnetic
shielding to keep radiated interference out of critical preamplifier circuits. Internal
line conditioning circuitry filters RF noise on the AC power, and compensates for
asymmetric power waveforms and DC on the mains.
Power for the preamplifier’s analog stages comes from a large 170 VA toroidal
transformer, with four 8-amp bridge rectifiers and 39,600 microfarads of filter
capacitance. A dedicated 90 VA toroidal transformer powers the preamplifier’s
digital control circuitry. The preamplifier has as much power supply capability as
many stereo power amplifiers.
6
In stand-by mode, all the analog circuitry continues to operate at the same bias
current; however, the main analog supply voltages decrease by 30 percent. The
result is a corresponding 30 percent reduction in power consumption and heat
without the need to wait for the electronics to “warm up” before listening.
Revolutionary Krell CAST Technology
Current Audio Signal Transmission, termed CAST, is a revolutionary method of
connecting 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 is 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 loudspeaker.
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 components are eliminated. Cable impedances and their effects on the transmitted signal are non-existent.
How CAST and Krell Current Mode Interact
While CAST is a new method of transferring the musical signal between components, 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,
7
continued
(SECTION ONE: Evolution 202 Features and Technology continued)
Krell Current Mode maintains the integrity of the signal within the component and
CAST preserves the transmitted signal between components. Together, CAST and
Krell Current Mode technologies unify separate Krell components into a
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 typically suffers from phase distortions in voltage circuits.
CAST Cable Construction
A CAST system uses cables manufactured by Krell and other manufacturers specially 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 developed for every CAST cable made.
Evolution CAST
single
By employing radical current mirror circuitry, the Evolution 202 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 expression of technology to date.
8
Definition of Terms
The following are definitions of key terms used in this owner’s reference:
Inputs and Outputs
Balanced
A symmetrical input or output circuit that has equal impedance from both input
terminals to a common ground reference point. The industry standard for professional and sound recording installations, balanced connections have 6 dB more
gain than single-ended connections and allow the use of long interconnect cables.
Balanced connections are completely immune to induced noise from the system
or the environment.
CAST and Evolution CAST
Krell Current Audio Signal Transmission, or CAST, is a proprietary Krell circuit technology for connecting analog components, transmitting the audio waveform
between components in the current domain rather than in the voltage domain. The
speed and bandwidth provided by Krell CAST and its circuitry update, Evolution
CAST, yield accurate, realistic music reproduction, enabling connected components to perform as if they are all part of a single circuit.
Single-ended
A two-wire input or output circuit. Single-ended connections are not recommended for connections requiring long cable runs. Use care when using single-ended
connections, because the ground connection is made last and broken first. Turn
the system off/on prior to making or breaking single-ended connections.
Operation
Off
When the stand-by/power LEDs are not illuminated, the preamplifier is off.
Stand-by
A low-power-consumption status that keeps the audio and regulator circuits at
idle. The stand-by/power LEDs are illuminated in red, when the preamplifier is in
stand-by mode. Krell recommends leaving the preamplifier in stand-by mode when
it is not playing music.
Operation
When the standby/power LEDs are illuminated in blue, the preamplifier is in operational mode and ready to play music.
9
continued
(SECTION ONE: Definition of Terms continued)
Technology
Krell Current Mode
A proprietary Krell circuit topology in which the audio gain stages of a component
operate in the current rather than voltage domain. This unique technology provides
the component with exceptional speed, and a wide bandwidth.
10
SECTIONTWO
Unpacking and Placement
This section describes the procedures for safely unpacking and placing your
Evolution 202 Preamplifier. The Evolution 202 preamplifier is shipped in 1 carton
consisting of 2 chassis: 1 power supply chassis and 1 preamplifier chassis.
Opening the Evolution 202 Shipping Carton
The Evolution 202 shipping carton measures 22.3 in. (56.6 cm) wide by 23.5 in.
(59.7 cm) high by 16.2 in. (41.1 cm) deep.
Preamplifier Chassis. This measures 17.3 in. (43.8 cm) wide by 3.8 in. (9.7 cm)
high by 18.3 in. (46.4 cm) deep, and weighs 18 lbs. (8.1 kg).
Power Supply Chassis. This measures 17.3 in. (43.8 cm) wide, by 3.8 in. (9.7 cm)
high, by 17.7 in. (44.8 cm) deep, and weighs 28 lbs. (12.7 kg).
To Remove the Preamplifier from the Shipping Carton
1. Open the shipping carton and remove the top layer of foam. The carton con-
tains these items:
1 Preamplifier chassis
1 Power supply chassis
1 IEC Connector (AC Power) cord
1 12-pin DC cable
1 Remote control
2 AAA-size 1.5 Volt batteries for the remote
1 T-10 Torx wrench for the remote control
1 Owner’s Reference
2. Carefully remove the preamplifier, power supply, and accessories from the box.
3. Place the preamplifier and power supply in a safe location, and remove the
protective plastic wrapping.
4. Place the power supply chassis where you intend to use the preamplifier.
Krell recommends that you place the preamplifier chassis on top of the power
supply chassis.
11
continued
SECTION THREE
Quick Start
To access the full array of available functions for the Evolution 202, please read
this entire owner’s reference manual. The abbreviated routine in this Quick Start
section will allow you to connect and operate the Evolution 202 quickly and enjoy
its basic functions.
The front and rear panels are shown in the diagrams on pages 15 and 22. Each
button or feature is labeled with a callout number, and these numbers are shown
in brackets in the sections below. (In the following instructions, the word “button”
refers to a front panel operation, and “key” refers to a remote control operation.)
Connecting the Evolution 202 to Your System
Position the preamplifier and power supply where you intend to use them in
your system. Do not move the chassis after they are connected.
1. Connect the power supply chassis and the preamplifier chassis with the 12-pin
DC cable provided, using the back panel DC power connectors (24).
2. Neatly arrange and organize wiring to and from the preamplifier and all compo-
nents. Separate the AC wires from any audio cables to prevent hum or other
unwanted noise from being introduced into the system.
3. Connect the outputs of your source equipment to the appropriate CAST (18),
balanced (15), single-ended (16), or tape inputs (17) on the Evolution 202.
4. Connect the main outputs (20) on the Evolution 202 to your amplifier’s inputs.
5. Connect the supplied AC power cord to the IEC power cord receptacle (27) of
the power supply unit.
6. Plug the other end of the AC power cord into AC power. The display (3) scrolls
through
minate red, indicating that the Evolution 202 is in stand-by mode. When the
scrolling stops, the Evolution 202 is ready to be powered on.
Note
Use only the power cord provided with the preamplifier to make the connection to AC
power. Operation with a power cord other than the one supplied by Krell could induce
noise, limit current, or otherwise impair the ability of the preamplifier to perform optimally.
EVOLUTION 202 SOFTWARE VERSION, and the stand-by/power LEDs (7) illu-
13
continued
(SECTION THREE: Quick Start)
Operating the Evolution 202
After the Evolution 202 is connected to your system and to AC power, and the
front panel display has stopped scrolling, begin operation:
1. Press the power button (1) on the front panel, or the remote control power key.
The standby/power LED turns blue. The display shows the factory default
S-1, and level: -INF. The Evolution 202 is now in the operational mode.
input:
2. With the preamplifier output muted, or the volume fully attenuated, select a
source manually using the front panel input select buttons (8, 9, or 10) or the
remote input select keys. Start playing the source. Use the level control knob
(14) or the remote level keys to set the volume to a comfortable level.
3. To return the preamplifier to the stand-by mode, press the power button (1) or
remote power key.
Krell recommends leaving the Evolution 202 in the stand-by mode when it is
not playing music.
14
SECTION FOUR
Anatomy of the Evolution 202
This section describes the Evolution 202 Preamplifier functions.
Figure 1 Evolution 202 Preamplifier and Power Supply Front Panels
1 Power Button
7 Stand-by/Power LED
2 Infrared Emitter
4 Infrared Sensor
3 Front Panel Display
5 Menu Button
6 Enter Button
8 Single-ended Input
Selection Buttons
9 Balanced Input
Selection Buttons
10 CAST Input Selection Buttons
11 Tape Button and LED
12 Mute Button and LED
13 Phase Button and LED
14 Level Control Knob
Inset Preamplifier and Power Supply:
Stacked View
15
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