Page 2 - IMPORTANT SAFETY INSTRUCTIONS
Evolution 302, 402, 403, 600 and 900 Power Amplifiers Owner’s Reference, v 07.0 Krell Industries, Inc.45 Connair RoadOrange, CT 06477-3650 USA 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. K...
Page 3 - Contents
3 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 Car...
Page 4 - List of Illustrations
4 List of Illustrations Figure 1, page 13 Evolution Amplifier Front Panel Figure 2, page 15 Evolution 302 Back Panel Figure 3, page 16 Evolution 402 Back Panel Figure 4, page 17 Evolution 403 Back Panel Figure 5, page 18 Evolution Monaural Amplifier Back Panel
Page 5 - A Letter from Dan D’Agostino
5 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. These four new models utilize Active Cascode Topology, a unique cir...
Page 6 - ONE; Evolution Amplifier Features and Technology; Features
6 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 five amplifier models in the Evolution Series: the 302 Stereo Power Ampli...
Page 7 - Revolutionary Krell CAST Technology; CAST Basics
7 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...
Page 8 - CAST Cable Construction; Evolution CAST; The Best Musical Performance
8 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 bandwidt...
Page 9 - Definition of Terms; Inputs and Outputs
9 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 profes- sional and sound...
Page 10 - Technology
10 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 topolog...
Page 11 - Unpacking and Placement; Opening the Evolution Amplifier Shipping Carton; TWO
11 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 30. Two people are needed to rem...
Page 12 - Placement; AC Power Guidelines
12 Placement Before you install an Evolution amplifier into your system, please follow the guide- lines 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, ...
Page 13 - THREE; Anatomy of an Evolution Amplifier
13 SECTION THREE Anatomy of an Evolution Amplifier This section describes Evolution amplifier functions. Figure 1 Evolution Amplifier Front Panel (Evolution 402 shown) 1 Power Button2 Power Status Indicator Power continued
Page 14 - Front Panel Description
14 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 ...
Page 19 - Back Panel Description; Outputs
19 Back Panel Description See Figure 2, 3, and 4 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 Bindi...
Page 20 - Remote Connections
20 Remote Connections 7 12 VDC In/Out (12 V Trigger) The 12 V trigger allows you to turn the Evolution amplifier on or off, or to and from 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 ...
Page 21 - FOUR; CAST Connections; Balanced Connections; XLR Pin Configuration; Single-ended Connections
21 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...
Page 22 - Evolution DC Protection Circuitry/Using Tube Preamplifiers; Connection Steps
22 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 ampl...
Page 23 - Evolution Amplifier Operation; Powering Off; FIVE
23 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 preampli...
Page 24 - Troubleshooting System Noise; How to Evaluate Amplifier Operation; SIX
24 Troubleshooting System Noise AC grounding becomes critical when connecting high-performance audio compo- nents. 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 loud- speakers. This often occurs when introdu...
Page 25 - Error Codes
25 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...
Page 26 - Questions and Answers; SEVEN
26 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, us...
Page 27 - Warranty
27 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 andDVD players carry a limited warranty o...
Page 29 - Return Authorization Procedure
Return Authorization Procedure How to Expedite Service If you believe there is a problem with your component, please contact your deal- er, 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 th...
Page 30 - Specifications
Specifications Measurement Evolution 302 Amplifier Evolution 402 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 SIGNAL-TO-NOISE RATIO Wideband, unweighted, referred to fullpower output“A” weighted...
