Krell Industries Stereo Amplifier Evolution One User Manual

EVOLUTION  
EVOLUTION ONE  
MONAURAL POWER AMPLIFIER  
OWNER’S REFERENCE  
 
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  
iii  
1
 
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  
iv  
 
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.  
continued  
1
 
(A Letter from Dan D’Agostino continued)  
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
 
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 KSA100 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.  
continued  
3
 
(SECTION ONE: About Krell continued)  
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.  
4
 
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  
continued  
5
 
(SECTION ONE: About Krell continued)  
(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.  
6
 
Ensuring Maximum Performance  
“My pursuit of excellence in sound reproduction and  
my love of great musical performance has led me  
to the Evolution One Amplifier, and fuels the ongoing  
Evolution design effort at Krell.”  
Dan D’Agostino  
The Krell Evolution One Monaural Power Amplifier, built upon the foundation of  
huge, regulated power supplies and output stages, is designed to drive any  
loudspeaker with complete control. The product of breakthrough Krell technolo-  
gy, this amplifier provides a sound that is supremely dynamic and musical.  
Indeed, it is the sound of the music itself.  
Core Technologies  
Class A, Balanced, Current Mode Gain  
Topologies from Input to Output  
Audio signal voltages are converted to currents at the amplifier input, and the  
audio signal remains in the current domain throughout the entire amplifier until  
the output stages. All signal gain is realized in the current domain using propri-  
etary multiple-output current mirrors with extraordinary open loop linearity. The  
current mirrors in the final gain stages use 36 pairs of high voltage, high speed  
transistors. Originally developed for demanding, high bandwidth video circuits,  
these transistors help yield gain stages with superb accuracy and very low dis-  
tortion. The signal path is fully complementary and fully balanced from input to  
output. The driver and output stages use 28 pairs of 150 Volt, 14 Amp, 50  
megahertz power transistors mounted on Krell-designed high efficiency heat  
sinks.  
All transistors operate in Class A mode. Independent complementary pre-  
driver and driver stages for the positive and negative output transistors make  
the output stages extremely fast and linear. The output stage develops 450  
Watts into an 8 Ohm load, 900 Watts into 4 Ohms, and 1800 Watts into 2  
Ohms. This unique circuit is impervious to low-impedance or reactive loads;  
the Evolution One amplifier simply drives any loudspeaker with absolute confi-  
dence, achieving the very best possible sonic results.  
continued  
7
 
(SECTION ONE: About Krell continued)  
Impedance Advantage  
The output impedance of the final gain stages is one hundredth that of the final gain  
stage in most power amplifiers. This provides extremely wide bandwidth and very  
high current capability. The amplifier does not employ global negative feedback—the  
final gain stages use only 8 dB of local, nested negative feedback. This is one five-  
hundredth the amount used in most solid-state power amplifiers. The result is an  
extraordinarily open, liquid, effortless sound.  
Robust Power Supply Regulation  
For Absolute Voltage Stability  
The rails powering the amplifier’s low level and gain stages are regulated twice  
for total immunity from fluctuations in the AC mains and virtually noise-free out-  
put. All the regulators use current-mode circuitry for wide bandwidth, low output  
impedance, and complete immunity to varying load conditions. The high-current  
regulators powering the amplifier output stages use fully complementary gain  
stages and output drivers. The resulting wide bandwidth and low output imped-  
ance of the Evolution One surpasses even the stringent demands of the amplifier  
output stages.  
The driver and output stages in the high current regulators use 14 pairs of the  
same robust, high performance power transistors used in the amplifier output  
stages. All the regulators are located in the amplifier chassis to provide ultra low  
impedance supply rails for the audio circuitry.  
Evolution Bias Control Systems  
The new Evolution Bias system features 12 individual bias levels for optimum  
performance and efficiency. Evolution Bias constantly compares the audio signal  
at the input stage with impedance at the output stage, and adjusts the bias cur-  
rent accordingly. In addition, a proprietary bias monitor continuously measures  
and adjusts the output stage bias, eliminating the need for future adjustment or  
calibration.  
8
 
Separate Power Supplies Are Quiet and Powerful  
Housed in a separate chassis, the power supply makes use of extensive electri-  
cal and magnetic shielding to keep radiated interference out of critical amplifier  
circuits. Internal high current line conditioning circuitry filters RF noise on the  
AC mains, as well as compensating for asymmetric power waveforms and DC  
on the mains. A dedicated 165 VA toroidal transformer with six independent  
secondary windings powers the amplifier’s low level stages, gain stages, and  
control circuitry. Power for the high current regulators and amplifier output stages  
comes from two massive 2500 VA toroidal transformers. These in turn drive eight  
35-amp bridge rectifiers and 120,000 microfarads of filter capacitance. High relia-  
bility connectors with 56 machined, gold plated, 20-amp contacts transmit these  
tremendous power reserves to the regulators.  
Advanced Microprocessor Control Monitors  
Critical Operational Parameters  
If the DC level at the amplifier inputs exceeds a safe level, the microprocessor  
control automatically switches in DC blocking capacitors to prevent damage to  
the input stages or the loudspeakers. The microprocessor control measures the  
load impedance in real time to optimize the performance of the amplifier and  
power supply or, in the case of a short circuit, to shut the amplifier off. It monitors  
the regulator output voltages, the symmetry between the two halves of the bal-  
anced output stages, and it monitors the operating temperatures of the three  
main heat sinks. If any of the heat sinks become too hot, the microprocessor  
control adjusts the operating parameters of the amplifier and power supply to  
help the circuitry run cooler. If the temperature of any of the heat sinks becomes  
unsafe, the microprocessor control shuts the amplifier off until it cools down.  
In the event of a major protection fault the microprocessor flashes a diagnostic  
code on the power/stand-by LED (4). The RMS output voltage and current sig-  
nals used by the microprocessor are also used by the power meter (6) (7), on the  
amplifier front panel, to display accurate power measurements. For more infor-  
mation on diagnostic codes, see Amplifier Troubleshooting, on page 26.  
continued  
9
 
(SECTION ONE: About Krell continued)  
Definition of Terms  
Following are the definitions of key terms used in your owner’s reference manual.  
Inputs and Outputs  
Balanced  
A symmetrical input or output circuit that has equal impedance from both input ter-  
minals 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 envi-  
ronment.  
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 components to perform  
as if they are all part of a single circuit.  
Operation  
Off  
When the power breaker switch on the back panel of the power supply is in the  
down position, and the power/stand-by LEDs (4), the backlight (5), and the power  
meter scale (6) are not illuminated, the amplifier is off.  
Stand-by  
A low power consumption status that keeps the audio and regulator circuits at idle.  
The power/stand-by LEDs (4) are illuminated in red, when the amplifier is in the  
stand-by mode. Krell recommends leaving the amplifier in the stand-by mode when  
it is not playing music.  
10  
 
(Operation continued)  
Operational Mode  
When the power/stand-by LEDs (4), the backlight (5), and the power meter scale (6)  
are illuminated in blue, the amplifier 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.  
Evolution Bias  
A patented microprocessor control system that maintains Class A bias operation  
regardless of musical demand. Class A bias is the most accurate method used to  
amplify musical signals. Evolution Bias maximizes an amplifier’s efficiency both in  
power consumption and heat generation.  
11  
 
SECTION  
TWO  
Unpacking and Placement  
This section describes the procedures for safely unpacking and placing your  
Evolution One Monaural Power Amplifier. Each Evolution One amplifier channel  
is shipped in 2 cartons: a power supply chassis in 1 carton and an amplifier  
chassis in the other carton.  
Opening the Amplifier Shipping Carton  
Each Evolution One shipping carton measures 27.5 in. (69.9 cm) wide by 12 in.  
(30.5 cm) high by 20.8 in. (52.8 cm) deep and contains 1 amplifier power supply  
chassis or 1 amplifier chassis.  
Power Supply Chassis. The combined weight of the shipping carton and the  
power supply chassis is 110 lbs. (49.8 kg). Each power supply chassis measures  
15.8 in. (40 cm) wide by 6.4 in. (16.1 cm) high by 20.5 in. (52.2 cm) deep and  
weighs 95 lbs. (43 kg).  
Amplifier Chassis. The combined weight of the shipping carton and the  
amplifier chassis is 70 lbs. (31.7 kg). Each amplifier chassis measures 15.8 in.  
(40 cm) wide by 6.2 in. (15.8 cm) high by 21.5 in. (54.7 cm) deep and weighs  
55 lbs. (24.9 kg).  
To Remove the Chassis from the Shipping Carton  
1. Open a shipping carton and remove the top layer of foam. You see these  
items:  
1 Evolution One power supply chassis or amplifier chassis  
1 packet containing the owner’s reference and warranty card  
2. Orient the shipping box so that one person stands at the front of the carton  
and the other person stands at the back of the carton.  
2 people needed  
12  
 
3. Simultaneously grasp the pair of cardboard handle cutouts at the front and  
back of the carton and lift the chassis straight up out of the carton.  
2 people needed  
4. Place the chassis in a safe location and remove the protective plastic  
wrapping.  
2 people needed  
5. Open the remaining 3 cartons of the Evolution One, using steps 1-4 above  
as a guide.  
2 people needed  
6. Place the power supply chassis where you intend to use the assembled ampli-  
fier channel. Krell recommends that you do not move the amplifier after it is  
assembled.  
2 people needed  
7. Locate the 4 locating pins (23) and the power connector (24) in the top plate of  
the power supply chassis. See Figure 4, on page 18.  
8. Make certain the amplifier chassis feet (13) and the amplifier power connector  
(not shown) align with the 4 power supply locating pins and power supply  
power connector as you lower the amplifier chassis onto the power supply  
chassis. Use the outer edges of the amplifier and power supply chassis as a  
guide. The dimensions of the chassis are identical. When viewed from the top,  
the power supply chassis will disappear beneath the amplifier chassis, indicat-  
ing proper alignment of the feet, pins, and power connectors.  
2 people needed  
9. Visually inspect the union between the amplifier and power supply chassis.  
Verify that the each of the amplifier chassis feet has descended upon the  
power supply chassis locating pins, and that both halves of the power connec-  
tors have mated squarely with one another.  
10. Press firmly on the amplifier chassis to ensure that the connector is properly  
engaged.  
continued  
13  
 
(SECTION TWO: Unpacking and Placement continued)  
Placement  
Before you install an Evolution One amplifier into your system, please follow the  
guidelines in this section to choose its proper location. This will facilitate a clean,  
trouble-free installation.  
Each Evolution One amplifier requires at least two inches (5 cm) of clearance  
on each side and at least eight inches (20 cm) of clearance above the compo-  
nent to provide adequate ventilation. An Evolution One amplifier channel meas-  
ures 15.8 in. (40 cm) wide by 12.5 in. (31.6 cm) high by 21.5 in.(54.7 cm) deep  
and weighs 150 lbs. (67.9 kg).  
Although Evolution Bias circuitry reduces the high heat dissipation and heat out-  
put of traditional Class A circuitry, Evolution One amplifiers still can become hot  
under normal operation. When the front and rear of a cabinet are open, the air  
space between the chassis and shelf must be unobstructed. If you place the  
amplifier in a closed cabinet, you may need to modify shelf spacing or use small  
fans to increase ventilation.  
Place the amplifier as close to the loudspeakers as possible. Although Krell CAST  
technology permits you to use interconnect cables of any length, try to keep the  
cable length to a minimum. All Evolution One amplifiers drive the lowest imped-  
ances with ease. When impedance is added due to long loudspeakers cable  
lengths, amplifier power is wasted in the cable. Long loudspeakers cables reduce  
the maximum power that is delivered in the loudspeakers.  
AC Power Guidelines  
Each Evolution One amplifier channel needs to be operated from a dedicated AC  
circuit rated at a minimum of 20 amps. A 30 amp AC circuit is preferable, but not  
required.  
Use the power cord shipped with the amplifier channel to make the AC connection.  
Operation with a power cord other than the one supplied by Krell may induce  
noise, limit current, or otherwise impair the amplifier’s ability to perform optimally.  
14  
 
SECTION  
THREE  
Anatomy of an Amplifier  
This section describes Evolution One features and benefits.  
Figure 1 Evolution One Amplifier and Power Supply Chassis Front Panels  
1
5
6
7
8
CAST  
50W  
POWER  
5000W  
4
3
9 10  
11  
12  
2
4
1 Amplifier Chassis  
2 Power Supply Chassis  
3 Power/Stand-by Button  
4 Power/Stand-by LED  
5 Backlight  
Inset  
Evolution One  
Amplifier Channel  
Front Panel View  
6 Power Meter Scale  
7 Power Meter Wand  
8 CAST LED  
13  
9 50 W Scale LED  
10 5000 W Scale LED  
11 Cast/Balanced Button  
12 Meter Range Button  
13 Amplifier Feet  
14  
14 Power Supply Feet  
continued  
15  
 
(SECTION THREE: Anatomy of an Amplifier continued)  
Figure 2 Evolution One Amplifier and Power Supply Chassis Back Panels  
1
BALANCED  
INPUT  
CAST  
INPUT  
IN  
IN  
OUT  
EVOLUTION ONE  
KRELL INDUSTRIES, INC.  
45 CONNAIR ROAD  
ORANGE, CT 06477-3650  
USA  
NO USER SERVICEABLE PARTS INSIDE  
MADE IN USA  
15  
16  
18  
19  
17  
2
50/60 Hz  
EVOLUTTION ONE  
KRELL INDUSTRIES, INC.  
45 CONNAIR ROAD  
ORANGE, CT 06477-3650  
USA  
NO USER SERVICEABLE PARTS INSIDE  
MADE IN USA  
21  
20  
15 Balanced Input  
16 CAST Input  
17 Amplifier Binding Posts  
18 RC-5 Input  
19 12 V Trigger In/Out  
20 IEC Power Cord  
Receptacle  
21 Power Breaker Switch  
16  
 
Figure 3 Evolution One Amplifier Chassis Top  
17  
17 Amplifier Binding Posts  
22 Amplifier Front  
22  
continued  
17  
 
(SECTION THREE: Anatomy of an Amplifier continued)  
Figure 4 Evolution One Power Supply Chassis Top  
23  
24  
23  
23 Locating Pin  
24 Power Connector  
25 Power Supply Front  
25  
18  
 
SECTION  
FOUR  
Connecting the Evolution One  
to Your System  
This section describes Evolution One amplifier connections and outlines remote  
control options. Each Evolution One has a CAST 4-pin connector, a balanced input  
via an XLR connector, a 12 Volt trigger In/Out connection, and an RC-5 input on  
the back panel.  
CAST Connections  
Krell recommends using its proprietary Krell CAST system for unparalleled sonic  
performance for connections between an Evolution One amplifier and other  
CAST-equipped components. Krell CAST uses flexible interconnecting cables that  
can be drawn through tight spaces and concealed.  
Balanced Connections  
Evolution One amplifiers also offer balanced connections. Balanced connections  
not only can minimize sonic loss but also are immune to induced noise, especially  
for installations using long cables.  
Cable Connection Steps  
The following steps describe how to connect cables to an Evolution One  
amplifier:  
1. Turn off all power sources and components before connecting inputs and out-  
puts.  
2. Neatly organize wiring between to and from the amplifier and all components.  
Separate AC wires from audio cables to prevent hum or other unwanted noise  
from being introduced into the system.  
continued  
19  
 
(SECTION FOUR: Connections, continued)  
3. Connect the Krell CAST cables from your CAST-enabled preamplifier or  
source component to the left and right Krell CAST 4-pin bayonet inputs (16)  
on the amplifier (1) back panel. For balanced operation, connect the intercon-  
nect cable from your preamplifier to the balanced XLR input (15) on the ampli-  
fier back panel.  
4. Connect the loudspeaker cables to the amplifier binding posts (17), located on  
the amplifier back panel. Amplifier binding posts accept spade lugs only.  
5. Insert the AC mains power cord plug into the IEC power cord  
receptacle (20), on the back panel of the power supply chassis.  
6. Turn to Amplifier Operation, on page 22.  
Note  
If a CAST and balanced source are connected to the amplifier during the initial installa-  
tion, the Evolution One amplifier defaults to CAST, when it is powered on. If only one  
source is connected, the amplifier will automatically select that source. For more informa-  
tion, see Switching Between CAST and Balanced Inputs, on page 23.  
DC Protection Circuitry / Using a Tube Preamplifier  
The Evolution amplifier has a built-in DC monitor that continuously monitors the  
audio signal at the input. If too high a level of DC is detected, the amplifier auto-  
matically mutes the output and engages DC coupling capacitors at the input  
stage.  
For more information about DC protection circuitry features, see Amplifier  
Troubleshooting, on page 26.  
20  
 
Remote Control Options  
The Evolution One amplifier is compatible with the remote controls included with  
the Krell Evolution Two preamplifier, other Krell preamplifiers or preamplifier/  
processors, and it is compatible with the Universal Krell Touch Screen Remote.  
Please contact your authorized Krell dealer, distributor, or Krell, if you wish to pur-  
chase a separate remote control for the Evolution One amplifier.  
The following remote control options are available, for amplifiers installed outside  
of the listening area:  
RC-5 Remote Control  
Each Evolution One amplifier has an RC-5 remote input (18) on the back panel.  
The RC-5 remote input accepts a remote command enabling it to switch  
between stand-by and operational modes and to switch between CAST and bal-  
anced inputs. The RC-5 remote control is used with a third party remote control  
system that provides RC5 (IR) data with the carrier intact, via a wired connection.  
A stereo tip, ring, sleeve 1/8” mini connector is used in the following configura-  
tion: Tip = RC-5 data, Ring = +5 V, Sleeve = GND.  
12 Volt Trigger  
The Evolution One amplifier has a 12 Volt trigger input/output connection (19) that  
sends and receives 12 VDC power on/off (12 V trigger) signals to/from other Krell  
components and other devices that incorporate a 12 Volt trigger. Mono 1/8” mini  
connectors are utilized with the following configuration: Tip = +12 V, Sleeve = GND.  
Notes  
When the Evolution One is in the operational mode, the 12 VDC Out provides  
12 Volts of DC output. When the component is in the stand-by mode or off, the DC output  
is 0 Volts.  
A minimum of 30 mA is required to operate the 12 Volt trigger.  
21  
 
SECTION  
FIVE  
Amplifier Operation  
Evolution One amplifiers are easy to operate. However, it is important to exer-  
cise care during operation due to the enormous power output of each amplifier.  
Switching between active sources (such as a CD player or a recording device)  
without muting the preamplifier output, or bumping or miscuing a source can  
generate large transients at low frequencies. Evolution One amplifiers may gen-  
erate enough power with these transients to damage loudspeakers.  
IMPORTANT  
Always mute or fully attenuate the preamplifier level when switching sources.  
Do not change input connections to the amplifier when the amplifier is on.  
Use care when setting high playback levels. Because of their tremendous  
reserves of clean power, Evolution One amplifiers can safely drive speakers to  
higher sound pressure levels than other amplifiers. Always lower the volume  
level at the first sign of loudspeaker distress.  
Powering On, Powering Down, and Powering Off  
When powering on any system, turn on amplifiers last. When powering down, turn  
off amplifiers first. Krell recommends leaving the Evolution One amplifier pow-  
ered down (in the stand-by mode) between listening sessions. Turn the amplifier  
off using the power breaker switch (21) on the back panel of the power supply  
chassis (2), when the system is not being used for an extended period of time.  
The procedure for amplifier operation follows:  
1. Insert the AC power cord plug into the dedicated wall outlet.  
2. Move the power breaker switch to the up position, to place the amplifier in  
stand-by mode. The power/stand-by LEDs (4) on the amplifier and power sup-  
ply chassis illuminate in red.  
22  
 
3. Press the power button (3), located underneath the far left edge of the amplifier  
chassis front panel. The power/stand-by LEDs (4) on the amplifier and power  
supply chassis illuminate in blue. The backlight (5) and the meter scale (6) on the  
amplifier chassis illuminate in blue.  
You may now switch between CAST and balanced operation. For more infor-  
mation, see Switching between Cast and Balanced Inputs, below.  
4. With the preamplifier muted, or the volume control completely lowered, select  
a source. Increase the volume control to the desired listening level.  
5. To place the amplifier in stand-by mode, press the power button (3) on the  
front panel. It is now safe to turn off the rest of the system.  
Switching Between CAST and Balanced Inputs  
If a CAST and balanced source are connected during the initial installation, see  
Cable Connection Steps, pages 19-20, the Evolution One defaults to CAST and  
the CAST LED illuminates in blue when the amplifier is powered on.  
If only one source is connected, the amplifier automatically selects that source. If  
the amplifier detects a balanced source, there is no illuminated LED.  
To switch between CAST and balanced inputs, press the CAST/Balanced button  
(11), located underneath the far right edge of the amplifier chassis front panel.  
CAST cables must be engaged for this function to be operational.  
continued  
23  
 
(SECTION FIVE: AMPLIFIER OPERATION continued)  
Adjusting Power Meter Modes  
The Evolution One amplifier uses microprocessors to monitor RMS output voltage  
and current signals. This information is output to a custom front panel power  
meter (6) (7), which displays an accurate power measurement for the selected  
meter range on the power meter scale (6). The power meter has 4 modes of opera-  
tion accessed by the meter range button (12): 50 WATT range, 500 WATT range, 5000  
WATT range, and OFF.  
There are two ways to cycles between the operational modes:  
Press the meter range button, located underneath the bottom right edge of the  
amplifier chassis front panel or,  
Press the select key (SEL) on the Evolution Two preamplifier, on another Krell pream-  
plifier, or on the Universal Krell Touch Screen Remote.  
Scale  
Blue Front Panel LED  
50W LED illuminates  
None  
Blue Backlight & Meter Scale Light  
Illuminated  
50 Watt  
500 Watt*  
5000 Watt  
Illuminated  
5000W LED illuminates  
Meter is inactive  
Illuminated  
Off  
Not illuminated  
*Factory default  
Power Meter Range and Power Meter Wand Action  
The power meter (6) (7) enables you to monitor the power output of the Evolution  
One amplifier. The 500 Watt scale is the factory default. The 50 Watt scale range is  
the most sensitive, and displays the smallest changes in power output, with the  
greatest physical movement of the power meter wand (7). Conversely, the 5000  
Watt scale is the least sensitive, and displays the largest changes in power output,  
with the smallest physical movement of the power meter wand.  
Turning Off the Lights on the Amplifier  
Channel Front Panel  
When the meter range button (12) cycled to OFF, the lights on the front panels are  
not illuminated.  
24  
 
Amplifier Care  
An Evolution One amplifier is capable of enormous power output, and it is impor-  
tant to exercise care during system operation. Avoid any action that can generate  
large transient signals. Always mute the preamplifier output before switching  
between active sources or cuing an LP. Do not change inputs to the amplifiers  
while the amplifiers are on.  
Use care when listening at high volume levels. Because of their tremendous reserve  
of clean power, Evolution One amplifiers can drive loudspeakers to much higher  
sound pressure levels than other amplifiers without clipping. Always lower the  
volume level at the first sign of loudspeaker distress.  
Exercise great care when handling an amplifier — especially at the back panel.  
Rings, necklaces, bracelets, and other pieces of metal jewelry can conduct elec-  
tricity. Consider removing them before touching any part of the back panel.  
25  
 
SECTION  
SIX  
Amplifier Troubleshooting  
System Protection  
Each Evolution One amplifier has a built-in DC monitor that continuously moni-  
tors the audio signal at the input, as well as other sophisticated protection cir-  
cuits that monitor other areas of the topology, in order to safeguard the amplifier.  
This circuitry constantly evaluates the operation of the amplifiers and provides  
protection against potentially damaging DC input or output and short circuits.  
Regulator operation is also continuously monitored to ensure constant voltage to  
the output stage. These protective systems are designed to prevent damage to  
Evolution One amplifiers or loudspeakers caused by other defective components,  
faulty wiring, system mishandling, or amplifier failure.  
26  
 
Evolution One amplifiers report operational issues by flashing the power/stand-by  
LEDs (4) in red, in a specific sequence, or by tripping the rear panel breaker (21),  
as follows:  
Diagnostic Codes  
Possible Condition  
Course of Action  
1 flash, pause, 2 flashes,  
repeat; then the amplifier  
reverts to stand-by mode  
Amplifier is over  
temperature  
Allow the amplifier  
to cool. When the LEDs  
stop flashing, the ampli-  
fier has cooled down.  
flash, pause, 5 flashes,  
repeat; then the amplifier  
reverts to stand-by mode  
Short circuit  
on output  
Check all connections  
at the amplifier and loud-  
speaker binding posts.  
Cycle the power breaker  
switch (21) on the power  
supply and attempt to  
power on the amplifier.  
Call the factory if the  
problem persists.  
1 flash, pause, 7 flashes,  
repeat; then the amplifier  
reverts to stand-by mode  
Line frequency error:  
The amplifier is set for  
60 Hz, but is attempt-  
ing to operate via a  
50Hz system.  
Contact your local  
authorized Krell  
dealer or distributor.  
Output mutes while music  
is playing, and then sound  
resumes.  
DC detected at input  
during playback.  
Check source and  
preamplifier for  
Input capacitors are  
automatically engaged.  
excessive DC output.  
Once DC has been elimi-  
nated, cycle the power  
breaker switch (21) to  
disengage the input  
capacitors.  
The power breaker switch  
(21) trips; then the amplifier  
powers off. The amplifier  
repeats this action when  
powered on.  
Possible component  
failure.  
Contact your local  
authorized Krell  
dealer or distributor, or  
the Krell Service  
Department.  
27  
 
Warranty  
Each Evolution Series amplifier has a limited warranty of five years for parts and  
labor on circuitry. Should this product fail to perform at any time during the warran-  
ty, Krell will repair it at no cost to the owner, except as set forth in this warranty.  
This warranty does not apply to damage caused by acts of God or nature.  
The warranty described on this page shall be in lieu of any other warranty, expressed  
or implied, including, but not limited to, any implied warranty of merchantability or  
fitness for a particular purpose. There are no warranties which exceed beyond  
those described in this document. If this product does not perform as warranted  
herein, the owner’s sole remedy shall be repair. In no event will Krell be liable for  
incidental or consequential damages arising from purchase, use, or inability to use  
this product, even if Krell has been advised of the possibility of such damages.  
Proof of purchase in the form of a bill of sale or receipted invoice substantiating  
that the unit is within the warranty period must be presented to obtain warranty  
service. The warranty begins on the date of the original retail purchase, as noted  
on the bill of sale or receipted invoice from an authorized Krell dealer or distribu-  
tor. Previously owned equipment, when re-purchased from an authorized Krell  
dealer or distributor, has the balance of the original warranty, based on the origi-  
nal date of manufacture.  
The warranty for Krell products is valid only in the country to which they were  
originally shipped, through the authorized Krell distributor for that country, and at  
the factory. There may be restrictions on or changes to Krell’s warranty because  
of regulations within a specific country. Please check with your distributor for a  
complete understanding of the warranty in your country.  
If a unit is serviced by a distributor who did not import the unit, there may be a  
charge for service, even if the product is within the warranty period.  
Freight to the factory is your responsibility. Return freight within the United States  
(U.S.A.) is included in the warranty. If you have purchased your Krell product outside  
the U.S.A. and wish to have it serviced at the factory, all freight and associated  
charges to the factory are your responsibility.  
28  
 
Krell will pay return freight to the U.S.A.-based freight forwarder of your choice.  
Freight and other charges to ship the unit from the freight forwarder to you are also  
your responsibility.  
Krell is not responsible for any damage incurred in transit. Krell will file claims  
for damages as necessary for units damaged in transit to the factory. You are  
responsible for filing claims for shipping damages during the return shipment.  
Krell does not supply replacement parts and/or products to the owner of the unit.  
Replacement parts and/or products will be furnished only to the distributor perform-  
ing service on this unit on an exchange basis only; any parts and/or products  
returned to Krell for exchange become the property of Krell.  
No expressed or implied warranty is made for any Krell product damaged by  
accident, abuse, misuse, natural or personal disaster, or unauthorized modification.  
Any unauthorized voltage conversion, disassembly, component replacement,  
perforation of chassis, updates, or modifications performed to the unit will  
void the warranty.  
In the event that Krell receives a product for warranty service that has been modified  
in any way without Krell authorization, all warranties on that product will be void.  
The product will be returned to original factory layout specifications at the owner’s  
expense before it is repaired. All repairs required after the product has been returned  
to original factory specifications will be charged to the customer, at current parts  
and labor rates.  
All operational features, functions, specifications, and policies are subject to change  
without notification.  
To register your product for warranty benefits, please complete and  
return the Warranty Registration Card enclosed in the shipping box within  
15 days of purchase. Thank you.  
29  
 
Return Authorization Procedure  
If you believe there is a problem with your component, please contact your dealer,  
distributor, or the Krell factory to discuss the problem before you return the component  
for repair. To expedite service, you may wish to complete and e-mail the Service  
Request Form in the Service Section of our website at:  
To contact the Krell Service Department  
TEL  
203-799-9954, Monday-Friday  
9:00 AM to 5:00 PM EST  
203-799-9796  
FAX  
E-MAIL  
Evolution One  
PRODUCT  
MODEL NUMBER  
SERIAL NUMBER  
To return a product to Krell, please follow this procedure  
so that we may serve you better:  
1. Obtain a Return Authorization Number (R/A number) and shipping address from  
the Krell Service Department.  
2. Insure and accept all liability for loss or damage to the product during shipment  
to the Krell factory and ensure all freight (shipping) charges are prepaid.  
The product may also be hand delivered if arrangements with the Service Department  
have been made in advance. Proof of purchase will be required for warranty validation  
at the time of hand delivery.  
IMPORTANT  
Use the original packaging to ensure the safe transit of the product to the factory, dealer,  
or distributor. Krell may, at its discretion, return a product in new packaging and bill the  
owner for such packaging if the product received by Krell was boxed in nonstandard pack-  
aging or if the original packaging was so damaged that it was unusable. If Krell deter-  
mines that new packaging is required, the owner will be notified before the product is  
returned.  
To purchase additional packaging, please contact your authorized Krell dealer,  
distributor, or the Krell Service Department for assistance.  
30  
 
Specifications  
Frequency response  
Inputs  
20 Hz to 20 kHz 0.05 dB  
0.6 Hz to 220 kHz +0, –3 dB  
1 balanced via XLR connector  
1 CAST via 4-pin bayonet connector  
Signal-to-noise ratio  
118 dB, “A”-weighted  
Outputs  
1 pair Krell binding posts  
Gain  
25.8 dB  
Dimensions  
Amplifier chassis:  
15.8 in. W x 6.2 in. H x 21.5 in. D  
40 cm W x 15.8 cm H x 54.7 cm D  
Total harmonic distortion  
<0.01% at 1 kHz, at 450 W, 8 Ohms  
<0.1% at 20 kHz, at 450 W, 8 Ohms  
Power supply chassis:  
15.8 in. W x 6.4 in. H x 20.5 in. D  
40 cm W x 16.1 cm H x 52.2 cm D  
Input impedance  
Balanced: 100 kHz  
CAST: 50 Hz  
Amplifier channel:  
15.8 in. W x 12.5 in. H x 21.5 in. D  
40 cm W x 31.6 cm H x 54.7 cm D  
Input sensitivity  
Balanced: 3.08 V RMS  
CAST: 3.08 mA RMS  
Weight  
Amplifier chassis:  
Shipped: 70 lbs., 31.7 kg  
Unit Only: 55 lbs., 24.9 kg  
Output power  
450 W RMS at 8 Ohms  
900 W RMS at 4 Ohms  
1800 W RMS at 2 Ohms  
Power supply chassis:  
Shipped: 110 lbs., 49.8 kg  
Unit Only: 95 lbs., 43 kg  
Output voltage  
170 V peak-to-peak  
60 V RMS  
Output current  
57 A peak  
Slew rate  
100 V/us  
Power consumption  
Standby: 225 W  
Idle: 300 W  
Maximum: 3600 W  
31  
 

Lathem Clock DDC2 User Manual
Lennox Hearth Indoor Fireplace SOLANA BK User Manual
Lennox Hearth Stove MPD35ST NM User Manual
Lennox International Inc Heat Pump 67M41 User Manual
Lenovo Tablet 3093AC6 User Manual
LG Electronics Blu ray Player GBC H20L User Manual
LG Electronics Cell Phone 3350232 User Manual
LG Electronics Refrigerator LSC 21943ST User Manual
Mamp;S Systems Stereo System XDM4600 User Manual
Meyer Sound Model Vehicle MG 3D M User Manual