Krell Industries EVOLUTION TWO MONAURAL PREAMPLIFIER Quick start guide

OWNER’S REFERENCE
EVOLUTION
EVOLUTION TWO
MONAURAL PREAMPLIFIER

Evolution Two Monaural Preamplifier
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 Evolution Two preamplifier must be placed on a firm, level surface where it is not exposed to
dripping or splashing.
The ventilation grids on the top of the Evolution Two preamplifier and the space underneath the
Evolution Two preamplifier must be unobstructed at all times during operation. Do not place flam-
mable material above or beneath the preamplifier.
Before making connections to the Evolution Two 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 quali-
ty, free from frayed ends, short circuits, or cold solder joints.
Do not connect an RS-232 cable to the phono power port. Output from the phono power port can
seriously damage your computer. Do not connect the cable from a Krell KPE phono stage to the
RS-232 port.
THERE ARE NO USER SERVICEABLE PARTS INSIDE AN EVOLUTION TWO MONAURAL
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™ is a trademark of Krell Industries, Inc. and is a Krell technology
based on U.S. Patent No. 5,331,291. CAN Link™, 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 307773

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, Definition of Terms
SECTION TWO: Unpacking and Placement, page 11
Opening the Evolution Two Shipping Carton
SECTION THREE: Quick Start, page 13
Connecting the Evolution to Your System,
Operating the Evolution Two
SECTION FOUR: Anatomy of an Evolution Two, page 15
Front Panel Description, Remote Control Description,
and Back Panel Description
SECTION FIVE: Connecting the Evolution Two to Your System, page 26
Input and Output Connections, Connection Steps,
Connections Using CAN Link
SECTION SIX: Evolution Two Operation, page 29
On/Off and Stand-by Operation, Play and Record,
Operation Using CAN Link
SECTION SEVEN: Customizing the Evolution Two, page 32
Navigation Conventions, Menu Functions
SECTION EIGHT: Questions and Answers, page 49
Troubleshooting System Noise
APPENDIX: CAN Link and Multiple Evolution Two Preamplifiers, page 51
WARRANTY, page 53
RETURN AUTHORIZATION PROCEDURE, page 55
SPECIFICATIONS, page 56

iv
List of Illustrations
Figure 1, page 15
Evolution Two Preamplifier Chassis and
Power Supply Chassis Front Panels
Inset Evolution Two Preamplifier Channel: Front Panel View
Figure 2, page 16
Evolution Two Remote Control
Figure 3, page 22
Evolution Two Preamplifier Chassis and
Power Supply Chassis Back Panels

A Letter from Dan D’Agostino
Dear Audio Enthusiast,
Thank you for your purchase of the Evolution Two preamplifier.
My new Evolution products represent a watershed in my design philosophy and in
my quest for audio components that deliver absolute truth in music reproduction.
The expanse of the Evolution Two monaural design has allowed me to explore
fully the advantages of current mode topologies. The resulting circuit utilizes no
feedback and has a bandwidth of 2 MHz.
I have always been fascinated by the artistry inherent in great musical performanc-
es, and my new Evolution Two preamplifier delivers the these performances in
their entirety, unaltered, to the amplifier. At the same time, the Evolution Two pre-
amplifier provides the flexibility and control necessary for the listener to thoroughly
enjoy a high performance audio system. It is my pleasure to make the Evolution
products available to you.
The preamplifier plays a vital role in audio playback. At no other point in the repro-
duction process is the music so vulnerable to change. The signal level at the pre-
amplifier stage is small, and is particularly susceptible to noise and distortion. In
order to solve this problem, the Evolution Two employs Krell Current Mode gain
stages from input to output, and Current Audio Signal Transmission (CAST)
receivers and transmitters. Unprecedented in Krell design history, these unique
topologies combine in the Evolution Two preamplifier to form a circuit that has no
audible sonic signature.
The Evolution Series represents a new direction for Krell, where breakthrough cir-
cuit topologies also represent the vanguard in convenience and control. Sophisti-
cated communication circuitry allows from two to eight preamplifiers to be linked
to a single master from which all user interface is accomplished. The Evolution
Two Monaural Preamplifier is designed to complement perfectly the Evolution One
Monaural Power Amplifier. Combine the Evolution One and Two with my new
LAT-1000 loudspeakers, and experience the extraordinary capabilities of an
Evolution System.
1continued

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
2
(A Letter from Dan D’Agostino continued)

About Krell
This section describes the Krell Legacy, the innovative features and technology of
the Evolution Two, and defines CAST and other 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 recog-
nized Krell components for standard-setting performance.
From the company’s inception to the present, Krell C.E.O. Dan D’Agostino has
continually “pushed the envelope” of performance in audio. His exploration of new
technologies, driven by his never-ending quest to elevate the standard of excel-
lence, has resulted in breakthrough audio designs. Evolution Two preamplifiers
build on this Krell legacy.
Dan D’Agostino remains committed to the development of new designs and tech-
nologies. And the Krell legacy will continue to evolve with products that deliver
innovative engineering, perfection in build quality, and outstanding audio perform-
ance.
3
SECTION ONE
continued

4
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 characteris-
tics 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 inter-
connects 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 eliminat-
ed. 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 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
(SECTION ONE: About Krell continued)

5
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.
continued

6
Ensuring Maximum Performance
“My pursuit of excellence in sound reproduction and
my love of great musical performance fuels the ongoing
Evolution design effort at Krell.”
Dan D’Agostino
The product of breakthrough Krell technology, the Evolution Two Monaural
Preamplifier works in tandem with the Evolution One Monaural Power Amplifier to
provide a sound that is supremely dynamic and musical. Indeed, it is the sound of
the music itself.
Core Technologies
Zero Feedback Balanced Current Mode Design
The signal path is fully complementary and fully balanced from input to output. All
transistors operate in Class A mode. CAST inputs drive a newly designed current-
mode balanced input stage, which uses a unique topology able to reject com-
mon-mode input noise over an unusually wide bandwidth.
Single-ended and balanced inputs drive a dynamically-cascoded JFET buffer,
which has tremendous open-loop linearity and very high input impedance, to elim-
inate loading effects. The voltage signals are then converted into balanced current
signals, the form in which they remain through the remainder of the signal path.
The audio signal remains in the current domain throughout the entire preamplifier.
Only at the single-ended and voltage outputs is it converted back to the voltage
domain.
All signal gain is realized in the current domain using proprietary multiple-output
current mirrors with nearly 500 times the open loop linearity of other designs.
Negative feedback is not used anywhere in the Evolution Two preamplifier, nor is it
necessary. Open-loop distortion is typically less than 0.005% (50 parts per mil-
lion), and the open loop bandwidth extends to two megahertz. The result is an
extraordinarily wide and deep image, with an open, effortless sound.
The signal switching relays are hermetically sealed and use gold-plated bifurcated
contacts for maximum signal integrity. Where needed multiple relays are connect-
ed in a “T” configuration to virtually eliminate crosstalk from unselected inputs.
The volume setting can be adjusted and displayed either numerically, from 0 to
151, or in dB, from –inf to +12.0 dB.
(SECTION ONE: About Krell continued)

7
Fully Balanced Discrete Volume Control
The volume control is realized with a 16-bit balanced resistor ladder, which uses
low-resistance, high-linearity solid-state switches and discrete precision resistors.
Control signals for the switches are optically coupled for low noise and maximum
signal integrity. The bandwidth and transient response of the preamplifier circuitry
are virtually unaffected by the volume setting. As a result high frequencies sound
especially smooth and extended, and music seems to emerge from “jet black”
silence. The analog and digital signal paths are not interconnected. Where neces-
sary, digital control signals are optically coupled to analog circuits.
The Evolution Two has two buffered tape outputs: one linked to the main signal-
selection bus, and another with its own independent signal-selection bus. This
allows the option of listening to one source while recording another, or the option
of connecting two tape decks having different input signals. Both tape outputs
have single-ended and voltage outputs. Either the fourth single-ended input or the
third balanced input can be user-configured as a tape monitor input, allowing the
opportunity to use home or professional recording equipment.
Separate Power Supply
Housed in a separate chassis, the power supply makes use of extensive electrical
and magnetic shielding to keep radiated interference out of critical preamplifier cir-
cuits. 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 analog stages comes from a large 170 VA toroidal transformer. This
transformer drives four 8-amp bridge rectifiers and 39,600 microfarads of filter
capacitance. Each monaural preamplifier has as much power supply capability as
many stereo power amplifiers.
The main regulators for the analog stages are scaled-down versions of those used
to power the output stages of the Evolution One amplifier. Operating in current
mode, with fully complementary gain stages and output drivers, wide bandwidth,
low output impedance, and high current capability, the main regulators easily
exceed the requirements of the analog stages. The driver and output stages in the
main analog regulators use five pairs of 150 Volt, 8 Amp, 40 megahertz power
transistors.
A dedicated 90 VA toroidal transformer with three independent secondary wind-
ings powers the preamplifier's digital control circuitry. The regulators for the con-
continued

8
(Separate Power Supply continued)
trol circuitry team ultra-stable voltage reference chips with the same discrete high-
current driver and output transistors used in the main analog regulators. These
ample power reserves are brought to the Evolution Two via high reliability 12-pin
connectors with machined, gold plated, three-amp contacts.
Secondary voltage regulators for each analog stage in the Evolution Two provide
ultra-quiet, rock-solid supply rails, as well as complete isolation between all the
analog stages.
When the Evolution Two is placed in stand-by, 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.
Advanced Microprocessor Control
and Custom Software
A user menu allows extensive customization of the preamplifier operation, includ-
ing (but not limited to) input names, input-specific gain trims, Theater Through-
put™, display brightness, and 12-volt triggers. Integration is supported via RS-
232,12 Volt trigger, and RC-5 inputs, as well as an IR transmitter for programming
a learning remote control.
A built-in digital network allows multiple preamplifiers to be linked together, blend-
ing the convenience of a single-chassis stereo preamplifier with the sonic perform-
ance obtainable only from individual monaural preamplifiers. Six or more preampli-
fier channels can be “daisy-chained” together and controlled simultaneously for
multi-zone or home theater applications. The digital link allows the user settings in
one preamplifier channel to be conveniently “cloned” to other linked preamplifier
channels. Similarly, upgraded software in one preamplifier channel can be installed
in other preamplifier channels using the digital link.
In the event that the DC level at any of the preamplifier channel outputs exceeds a
nominal level, sophisticated protection circuitry safely mutes the outputs, traces
the source of the excess DC, and displays a diagnostic message on the main dis-
play. On power-up, the microprocessor verifies that all the circuit boards in the
preamplifier channel are properly connected and are compatible with the version
of software installed.
(SECTION ONE: About Krell continued)

Definition of Terms
Following are the definitions of key terms used in this owner’s reference.
Configurations
CAN Link
The communication system that links multiple Evolution Two preamplifier channels
is a sophisticated system called a controller area network (CAN).
Linked Mode
In linked mode, functions including power, volume, balance, phase, record, mute,
and input selections are instantaneously transmitted between linked preamplifier
channels. Evolution Two preamplifiers use CAN Link to operate in linked mode.
Clone
A method of transmitting custom configurations between linked preamplifier chan-
nels.
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 profes-
sional 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 tech-
nology 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 compo-
nents 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 recommend-
ed 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.
9continued

Preamplifier
Channel
Also termed preamplifier or preamplifier channel. A channel is one Evolution Two,
comprised of one preamplifier chassis and one power supply chassis.
Right-terminated channel
Any right preamplifier channel that is last in a chain of linked Evolution preampli-
fiers is referred to as right-terminated. There is only one RG-45 link cable connect-
ed to a right-terminated channel.
Transmitter
Also termed transmitter preamplifier. The transmitter is a right-terminated preampli-
fier channel that sends IR, RC-5, and RS-232 data to the other linked preamplifier
channel(s), or receiver(s).
Receiver
Also termed receiver preamplifier. Receivers are linked preamplifier channels that
receive IR, RC 5, and RS-232 data from a right terminated preamplifier channel, or
transmitter.
Operation
Off
When the stand-by/power LEDs and the backlight grid are not illuminated, the pre-
amplifier 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 chan-
nel is in the stand-by mode. Krell recommends leaving the preamplifier in the
stand-by mode when it is not playing music.
Operation
When the backlight is illuminated in blue, the preamplifier is in the operational
mode and ready to play music.
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
(SECTION ONE: About Krell continued)

11
Unpacking and Placement
This section describes the procedures for safely unpacking and placing your
Evolution Two Monaural Preamplifier. Each Evolution Two preamplifier channel is
shipped in 1 carton consisting of 2 chassis: 1 power supply chassis and 1 pream-
plifier chassis.
Opening the Evolution Two Shipping Carton
Each Evolution Two 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. Each preamplifier chassis measures 17.3 in. (43.8 cm) wide
by 3.7 in. (9.5 cm) high by 18.5 in. (47 cm) deep, and weighs 21 lbs. (9.5 kg).
Power Supply Chassis. Each power supply chassis measures 17.3 in. (43.8 cm)
wide by 3.7 in. (9.5 cm) high by 17.3 in. (43.8 cm) deep, and weighs 31 lbs.
(14 kg).
Left/Right Channel Orientation
Evolution Two preamplifier channels are assembled as left or right channels.
Preamplifier RCA connectors (31, 36, 38, 40) are color coded. Left preamplifier
channels are assembled with white RCA connectors, and right preamplifier chan-
nels are assembled with red RCA connectors.
To Remove the Preamplifier Channel
from the Shipping Carton
1. Open a shipping carton and remove the top layer of foam. You see these
items:
1 Evolution Two preamplifier chassis
1 Evolution Two power supply chassis
1 AC Power cord
1 12-pin DC cable
1 RJ-45 control cable
1 remote control
2 AAA-size 1.5 Volt batteries for the remote
1 T-10 Torx wrench for the remote control
1 packet containing the owner’s reference and warranty card
SECTION TWO
continued

12
(To Remove the Preamplifier from the Shipping Box continued)
2. Carefully remove the preamplifier chassis, power supply chassis, and acces-
sories from the box.
3. Place the the preamplifier chassis and power supply chassis in a safe location
and remove the protective plastic wrapping.
4. Place the power supply chassis where you intend to use the assembled pre-
amplifier.
Krell recommends that you place the preamplifier chassis on top of the power
supply chassis. You can make 2 identical preamplifier/power supply stacks, as
individual left and right channels, or one 4-chassis stack, with both channels
combined in one stack.
5. Repeat Steps 1-5 for the remaining preamplifier channel(s).
Placement
Before you install an Evolution Two preamplifier into your system, please follow the
guidelines in this section to select a location for your component. This will facili-
tate a clean, trouble-free installation.
The Evolution Two preamplifier does not require a special rack or cabinet for
installation. Each preamplifier channel measures 17.3 in (43.8 cm) wide by 7.3 in.
(18.5 cm) high by 18.5 in. (47 cm) deep.
The Evolution Two preamplifier requires at least 2 inches of clearance on each side
and at least two inches of clearance above the component to provide adequate
ventilation. Installation inside cabinetry may require additional ventilation.
AC Power Guidelines
The Evolution Two preamplifier has superb regulation and does not require a dedi-
cated AC circuit. Avoid connections through extension cords or multiple AC
adapters. High quality 15 amp AC strips are acceptable. The use of AC line condi-
tioning devices is not recommended. The features provided by these devices are
already on board the Evolution Two. For more information, see Separate Power
Supply, on page 7.
(SECTION TWO: Unpacking and Placement continued)

continued
13
SECTION THREE
Quick Start
To access the full array of available functions for the Evolution Two Monaural
Preamplifier, please read the entire owner’s reference manual. The abbreviated
routine in this Quick Start section will allow you to connect and operate the
Evolution Two quickly and enjoy its basic functions.
Evolution Two preamplifier channels may be operated independently, or they may
be operated in linked mode, using CAN Link.
Connecting the Evolution Two to Your System
Position each power supply and preamplifier chassis where you intend to use
connected channels. Do 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 DC power connectors (47) on the back panels
(1-2).
IMPORTANT
Never connect two power supplies together.
2. In order to operate the Evolution Two preamplifier in linked mode, connect the
preamplifier channels together with the supplied RJ-45 control cable. In linked
mode, functions including power, volume, balance, phase, record, mute, and
input selections are instantaneously transmitted between linked preamplifier
channels.
When a system with linked preamplifier channels is powered on, left/right ori-
entation is established immediately, with no user intervention. For more infor-
mation on linked preamplifiers, see Appendix: CAN Link and Multiple
Evolution Two Preamplifiers, on page 51.
3. Neatly arrange and organize wiring to and from the Evolution Two preamplifier
and all components. Separate AC wires from audio cables to prevent hum or
other unwanted noise from being introduced into the system.
4. Connect the outputs of your source equipment to the appropriate CAST (34),
balanced (30), single-ended (31), or tape inputs (32, 33) on the Evolution Two.
5. Connect the appropriate main outputs (35-41) on the Evolution Two to your
amplifier.

14
(Connecting the Evolution Two To Your System continued)
6. On each preamplifier channel, connect the supplied AC power cord to the IEC
power cord receptacle (48).
7. On each preamplifier channel, plug the AC power cord into AC power. The
front panel display (15) scrolls through EVOLUTION 2 SOFTWARE VERSION, and the
red stand-by LEDs illuminate (4), indicating that the Evolution Two preamplifier
is in stand-by mode. The scrolling stops when the Evolution Two is ready to be
powered on.
Note
Use only the power cord provided with the preamplifier channel to make the connec-
tion 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 chan-
nel to perform optimally.
Operating the Evolution Two (Linked Mode)
After the Evolution Two is connected to your system and to AC power, and the
front panel display (15) has stopped scrolling, begin operation:
1. Press the power button on either preamplifier chassis front panel or the pwr
key (3) on the remote control. The blue backlights illuminate, the red stand-by
LEDs (4) turn off, and the front panel displays read INITIALIZING. The front panel
displays show the factory default input: S-1, and level: -INF. The Evolution Two
is now in the operational mode.
2. With the Evolution Two preamplifier output muted or the volume fully attenuat-
ed, select a source manually using the front panel input select buttons or the
input select keys on the remote control (8, 9, 10, 11). Start playing the source.
Use the level control knob or level keys (16) to set the volume to a comfortable
listening level.
3. To return the Evolution Two preamplifier to the stand-by mode, press the
power button or pwr key.
Krell recommends leaving the Evolution Two in the stand-by mode when it is
not playing music.
(SECTION THREE: Quick Start)

15
SECTION FOUR
Anatomy of an Evolution Two
This section describes Evolution Two Monaural Preamplifier functions.
Figure 1 Evolution Two Preamplifier Chassis and Power Supply Chassis Front Panels
1 Preamplifier Chassis
2 Power Supply Chassis
3Power Button
4 Stand-by LED
5 Power Backlight
6 IR Sensor
7 Infrared Transmitter LED
8 Single-ended Input
Selection Buttons
9Balanced Input
Selection Buttons
10 CAST Input Selection Buttons
11 Tape Button and LED
12 Mute Button and LED
13 Record Button and LED
14 Phase Button and LED
15 Front Panel Display
16 Level Control Knob
17 Menu Button
18 Enter Button
19 Preamplifier Chassis Feet
20 Power Supply Chassis Feet
Inset Evolution Two Preamplifier
Channel: Front Panel View
1
34 58910 11 12 13 14 1667
1817
2
4
15
POWER MENU ENTER
TAP E
PHASE
RECORD
MUTE
19
20
Chassis
Power
Remote
Functions
Preamplifier
Functions
Display
Level
Navigate/
Customize
continued

Figure 2 Evolution Two Remote Control
16
3 Power Key
8Single-ended Input
Selection Keys
9Balanced Input
Selection Keys
10 CAST Input
Selection Keys
11 Tape Key
12 Mute Key
13 Record Key
14 Phase Key
21 Main Bus Key
22 Balance Key
16 Level Keys
17 Menu Key
18 Enter Key
23 Pause Key
24 Play Key
25 Stop Key
26 Track Forward
and Back Key
27 Search Forward
and Back Key
28 Amplifier Power Key
29 Meter Select Key
18 17
28
29
8
3
12 13
14 21
11
26 27
16
23 24
9
10
22
25
(SECTION FOUR: Anatomy of an Evolution Two continued)
Power
Preamplifier
Functions
Level
Navigate/
Customize
CD
Functions
Amplifier
Functions