EVOLUTION EVOLUTION 400, AMPLIFIERS 302 AND 403 THREE-CHANNEL 600, 402 AND OWNER’S STEREO 900 MONAURAL REFERENCE
Evolution 302, 402, 403, 400, 600 and 900 Power Amplifiers Owner’s Reference, v08.0 Krell Industries, Inc. 45 Connair Road Orange, CT 06477-3650 USA TEL 203-298-4000 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.
Contents List of Illustrations, page 4 A Letter from Dan D’Agostino, page 5 SECTION ONE: Evolution Amplifier Features and Technology, page 6 Features, Revolutionary Krell CAST Technology, Definition of Terms SECTION TWO: Unpacking and Placement, page 11 Opening the Evolution Amplifier Shipping Carton SECTION THREE: Anatomy of the Evolution Amplifier, page 13 Front Panel Description, and Back Panel Description SECTION FOUR: Connecting an Evolution Amplifier to Your System, page 22 CAST Connections, Balanced
List of Illustrations Figure 1, page 13 Evolution Amplifier Front Panel Figure 2, page 15 Evolution 302 Stereo Back Panel Figure 3, page 16 Evolution 402 Stereo Amplifier Back Panel Figure 4, page 17 Evolution 403 Three-channel Amplifier Back Panel Figure 5, page 18 Evolution 400 Monaural Amplifier Back Panel Figure 5, page 19 Evolution Monaural Amplifier Back Panel 4
A Letter from Dan D’Agostino Dear Audio Enthusiast, Thank you for your purchase of a Krell Evolution Series amplifier. Evolution Series amplifiers continue my quest for amplifiers that deliver absolute truth in music reproduction. Active Cascode Topology is a unique circuit technique that minimizes distortion by applying from 2 to 3 times more active devices to each gain stage. The attributes of this topology is shared throughout the Evolution Series amplifiers.
SECTION ONE Evolution Amplifier Features and Technology This section describes the innovative features and technology of the Evolution Series amplifiers, and defines CAST and other key terms used in this reference. There are six amplifier models in the Evolution Series: the 302 Stereo Power Amplifier, the 402 Stereo Power Amplifier, the 403 Three-channel Power Amplifier, the 400 Monaural Power Amplifier, the 600 Monaural Power Amplifier, and the 900 Monaural Power Amplifier.
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.
(SECTION ONE: Evolution Amplifier 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 single global circuit. Krell Current Mode technology enjoys bandwidth increases up to an order of magnitude greater than their voltage based counterparts.
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.
(SECTION ONE: Definition of Terms continued) Technology Active Cascode Topology A unique circuit technique that minimizes distortion by applying from 2 to 3 times more active devices to each gain stage thereby reducing the load on individual devices and improving circuit-wide linearity. Krell Current Mode A proprietary Krell circuit topology in which the audio gain stages of a component operate in the current domain rather than the voltage domain.
TWO SECTION Unpacking and Placement This section describes the procedures for safely unpacking and placing your Evolution amplifier. The amplifier and accessories are shipped in 1 carton. The dimensions of the amplifier are shown in the specifications section starting on page 31. Two people are needed to remove the Evolution amplifier from its shipping box safely and easily. Opening the Evolution Amplifier Shipping Carton 1. Open the shipping carton and remove the top layer of foam.
(SECTION TWO: Unpacking and Placement continued) Placement Before you install an Evolution amplifier into your system, please follow the guidelines in this section to select a location for your component. This will facilitate a clean, trouble-free installation. Place the amplifier on a firm, level surface, away from excessive heat, humidity, or moisture.
SECTION THREE Anatomy of an Evolution Amplifier This section describes Evolution amplifier functions.
(SECTION THREE: Anatomy of an Evolution Amplifier continued) Front Panel Description See Figure 1 on the previous page Evolution amplifier front panel functions are described below: Power 1 Power Button Press this button to place the Evolution amplifier in operational mode. 2 Power Status Indicator The power status indicator is illuminated in red when the amplifier is in standby mode. The indicator illuminates in blue when the amplifier is in operational mode.
Figure 2 Evolution 302 Stereo Amplifier Back Panel Outputs Inputs Remote Power 3 4 5 6 7 8 9 10 Loudspeaker Binding Posts CAST Inputs Single-ended Inputs Balanced Inputs 12 VDC Out/In (12 V Trigger) Backlight Control IEC Power Cord Receptacle Power Breaker Switch 15 continued
Figure 3 Evolution 402 Stereo Amplifier Back Panel Outputs Inputs Remote Power 3 4 5 6 7 8 9 10 Loudspeaker Binding Posts CAST Inputs Single-ended Inputs Balanced Inputs 12 VDC Out/In (12 V Trigger) Backlight Control IEC Power Cord Receptacle Power Breaker Switch 16
(SECTION THREE: Anatomy of an Evolution Amplifier continued) Figure 4 Evolution 403 Multi-channel Amplifier Back Panel Outputs Inputs Remote Power 3 4 5 6 7 8 9 10 Loudspeaker Binding Posts CAST Inputs Single-ended Inputs Balanced Inputs 12 VDC Out/In (12 V Trigger) Backlight Control IEC Power Cord Receptacle Power Breaker Switch 17 continued
Figure 5 Evolution 400 Monaural Amplifier Back Panel Outputs Remote Power 3 4 5 6 7 8 9 10 Loudspeaker Binding Posts CAST Input Single-ended Input Balanced Input 12 VDC Out/In (12 V Trigger) Backlight Control IEC Power Cord Receptacle Power Breaker Switch 18
Figure 6 Evolution Monaural Amplifier Back Panel (Evolution 600 shown) Outputs Inputs Remote Power 3 4 5 6 7 8 9 10 Loudspeaker Binding Posts CAST Input Single-ended Input Balanced Input 12 VDC Out/In (12 V Trigger) Backlight Control IEC Power Cord Receptacle Power Breaker Switch 19
(SECTION THREE: Anatomy of an Evolution Amplifier continued) Back Panel Description See Figures 2, 3, 4, 5, and 6 on the previous pages The amplifier back panel provides access to the input and output connections, 12 V trigger inputs and outputs, and the AC power connection and switch. Back panel features and their descriptions follow: Outputs 3 Loudspeaker Binding Posts (one pair per channel) Each channel has one positive and one negative binding post. They accept spade lugs only.
Remote Connections 7 12 VDC In/Out (12 V Trigger) The 12 V trigger allows you to turn the Evolution amplifier on or to stand-by from other components. Out. The output sends 12 VDC (12 V trigger) power on/off signals to other Krell components and other devices that incorporate a 12 V trigger, allowing whole systems or parts of systems to be easily controlled remotely. Mono 3.5 mm connectors are used in the following configuration: Tip = +12 V, Sleeve = GND.
SECTION FOUR Connecting an Evolution Amplifier to Your System This section describes Evolution amplifier connections. Each Evolution amplifier channel has a CAST 4-pin connector, a balanced input via an XLR connector, a single-ended RCA connector, and a pair of loudspeaker binding posts. The rear panel also has 12 VDC trigger input and outputs, and a backlight remote trigger input. All inputs and outputs are located on the Evolution amplifier back panel.
Evolution DC Protection Circuitry/Using Tube Preamplifiers The high DC output of tube preamplifiers may exceed the active DC protection circuitry of the Evolution amplifiers. Excessive DC level in a signal can damage amplifiers, loudspeakers, or both. The single-ended inputs of the Evolution amplifiers are capacitor-coupled and DC does not pass through. Therefore, if connecting a tube preamplifier, use the single-ended inputs only.
SECTION FIVE Evolution Amplifier Operation The Evolution amplifiers are easy to operate. IMPORTANT When powering up any system, turn the amplifier on last. When powering down, turn it off first. This will prevent any turn-on and turn-off thumps in your loudspeakers. Always mute or fully attenuate the preamplifier level when switching sources. Do not change input connections to the amplifier when the amplifier is on.
SECTION SIX Troubleshooting System Noise AC grounding becomes critical when connecting high-performance audio components. When you mix and match high-performance audio components, each with its own ground potential, a low frequency hum may occur in one or both loudspeakers. This often occurs when introducing a new component into a system. If this happens when you place the Evolution amplifier into your system, follow these simple troubleshooting steps.
(SECTION SIX: Troubleshooting continued) Error Codes In the event of a problem, the power status indicator (2) will flash error code(s) in red. Errors are identified by a sequence of 3, 4, or 5 flashes. There is a pause between codes, and in the case where there is only one error code, the same code is repeated. Diagnostic Code Possible Condition Course of Action 3 flashes Excessive current draw Check loudspeaker and cables for short circuits.
SECTION SEVEN Questions and Answers Q. Should I leave my Evolution amplifier on at all times? A. For maximum amplifier performance, leave the back panel power breaker switch on at all times. This places the amplifier in stand-by mode. Evolution amplifiers are designed to be powered on and off from stand-by, using the front panel power button. This eliminates “cold start” degradation. The amplifier will operate at full performance within minutes. Q.
Warranty Krell products have a limited warranty. Amplifiers, preamplifiers, preamp/processors, and receivers carry a limited warranty of five years for parts and labor on circuitry. Loudspeakers carry a limited warranty of five years for parts and labor. CD and DVD players carry a limited warranty of five years for parts and labor on circuitry, and three years for parts and labor on mechanical parts.
If the product 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. Krell will pay return freight to the U.S.A.
Return Authorization Procedure How to Expedite Service 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: http://www.krellonline.
Specifications Measurement Evolution 302 Stereo Amplifier Evolution 402 Stereo Amplifier FREQUENCY RESPONSE 20 Hz to 20 kHz +0, –0.10 dB <0.5 Hz to 180 kHz +0, –3 dB 20 Hz to 20 kHz +0, –0.18 dB <0.5 Hz to 120 kHz +0, –3 dB Wideband, unweighted, referred to full power output “A” weighted >107 dB >106 dB >117 dB >116 dB GAIN 25.5 dB 25.4 dB TOTAL HARMONIC DISTORTION <0.02% at 1 kHz, at 300 W, 8 Ohms <0.02% at 1 kHz, at 400 W, 8 Ohms <0.15% at 20 kHz, at 300 W, 8 Ohms <0.
(Specifications continued) Measurement Evolution 403 3-channel Amplifier FREQUENCY RESPONSE 20 Hz to 20 kHz +0, –0.18 dB <0.5 Hz to 120 kHz +0, –3 dB Evolution 400 Monaural Amplifier SIGNAL-TO-NOISE RATIO Wideband, unweighted, referred to full power output “A” weighted >106 dB GAIN 25.4 dB TOTAL HARMONIC DISTORTION <0.02% at 1 kHz, at 400 W, 8 Ohms <0.
(Specifications continued) Measurement Evolution 600 Monaural Amplifier Evolution 900 Monaural Amplifier FREQUENCY RESPONSE 20 Hz to 20 kHz +0, –0.18 dB <0.5 Hz to 120 kHz +0, –3 dB 20 Hz to 20 kHz +0, –0.18 dB <0.5 Hz to 120 kHz +0, –3 dB Wideband, unweighted, referred to full power output “A” weighted >110 dB >113 dB >119 dB >122 dB GAIN 25.4 dB 25.4 dB TOTAL HARMONIC DISTORTION <0.02% at 1 kHz, at 600 W, 8 Ohms <0.02% at 1 kHz, at 900 W, 8 Ohms <0.15% at 20 kHz, at 600 W, 8 Ohms <0.
EVOLUTION 400, AMPLIFIERS 302 AND 403 THREE-CHANNEL 600, 402 AND OWNER’S STEREO 900 MONAURAL REFERENCE V08.0 KRELL 45 INDUSTRIES, CONNAIR ORANGE, TELL: CT 06477-3650 203-298-4000 E-MAIL: INC. ROAD • FA X : USA 203-891-2028 sales@krellonline.com h t t p : / / w w w. k r e l l o n l i n e .
