Krell Industries FBI User Manual

Instructions for Use

FBI

Fully Balanced

Integrated Amplifier

Owner’s Reference

FBI
Fully Balanced Integrated Amplifier
Instructions for Use

06.0

v

CONTACT
INFORMATION

This product complies with the
EMC directive (89/336/EEC)
and the low-voltage directive
(73/23/EEC).

Krell Industries, Inc.
45 Connair Road
Orange, CT 06477-3650 USA
TEL [phone]
FAX [phone]
E-MAIL [e-mail]
WEBSITE http://www.krellonline.com

IMPORTANT SAFETY INSTRUCTIONS

1. Read Instructions.

2. Keep these Instructions.

3. Heed all Warnings.

4. Follow all Instructions.

5. Do not use this apparatus near water.

6. Clean only with dry cloth.

7. Do not install near any heat sources such as radiators, heat registers,

stoves, or other apparatus (including amplifiers) that produce heat.

8. Unplug this apparatus during lightning storms or when unused for long

periods of time.

9. Refer all servicing to qualified service personnel. Servicing is required

when the apparatus has been damaged in any way, such as a power­supply cord or plug is damaged, liquid has been spilled or objects have
fallen into the apparatus, the apparatus has been exposed to rain or
moisture, does not operate normally, or has been dropped.

10. The FBI must be placed on a fir

to dripping or splashing.

11. The ventilation grids on the top and bottom of the FBI must be unob-

structed at all times during operation. Do not place flammable material
above or beneath the pr

eamplifier

12. Before making connections to the FBI , ensur e that the power is off and

other components are in mute or stand-by mode. Make sure all cable ter­minations are of the highest quality, free from frayed ends, short circuits, or
cold solder joints.

13. THERE ARE NO USER SER

ANCED INTEGRA

TED AMPLIFIER.

m, level surface where it is not exposed

.

VICEABLE PARTS INSIDE A FULLY BAL-

© 2006 by Kr

Please contact Krell if you have questions not addressed in this guide.

This pr
Industries, Inc., and is r
CAST™, Evolution CAST™, and Theater Thr
trademarks and trade names ar

ell Industries, Inc. All rights r

®

oduct is manufactur

ved P/N 309094-W

eser

ed in the United States of America. Kr

estricted for use by Kr

egister

e r

ell Industries, Inc., its subsidiaries, and authorized agents.

oughput™ ar

ed to their r

espective companies.

ell

is a r

e trademarks of Kr

ed trademark of Kr

egister

ell Industries, Inc. All other

ell

Contents

Page

INTRODUCTION 5
REVOLUTIONARY KRELL CAST TECHNOLOGY 6
DEFINITION OF TERMS 8
UNPACKING 10
PLACEMENT 11

AC Power Guidelines
FRONT PANEL / REMOTE CONTROL DESCRIPTION 13
REMOTE CONTROL ONLY 15

Battery Installation and Removal

Remote Control Only Functions
BACK PANEL DESCRIPTION 18
CONNECTING THE FBI TO YOUR SYSTEM 20

Connection Steps
OPERATING YOUR

Amplifier Operation

Tape Input and Output
OPTIONAL CONFIGURATIONS

Configuring the FBI

Preamplifier Output
HOW TO TROUBLESHOOT SYSTEM NOISE 25
QUESTIONS AND ANSWERS 26

ARRANTY

W
RETURN AUTHORIZATION PROCEDURE 29
SPECIFICA

TIONS Back Cover

FBI

for Theater Thr

oughput

21

23

27

Krell FBI

3

Illustrations

Page

FIGURE 1 The FBI Front Panel 12
FIGURE 2 The FBI Remote Control 12
FIGURE 3 The FBI Back Panel 17

4 Krell FBI

Introduction

Thank you for your purchase of the Krell FBI Remote Control Inte­grated Amplifier. This fully integrated amplifier and preamplifier has
a fully balanced signal path from input to output and employs a
wide bandwidth design with low negative feedback for sonic accu­racy throughout the frequency spectrum. All circuits, including the
amplifier output stage, operate in pure Class A mode.

The Fully Balanced Integrated Amplifier is a large-format integrat­ed, and as such offers all the power and control afforded by big
Krell amplifiers in a convenient, integrated package that is simple
to operate. The remote control accesses all functions, while a 12 V
trigger connection allows the Fully Balanced Integrated Amplifier to
interface easily with other components. The Theater Throughput
feature provides easy integration into a home theater system.

This owner’s reference manual contains important information on
the placement, installation, and operation of the Fully Balanced
Integrated Amplifier. Please read this information carefully. A thor­ough understanding of these details will help ensure satisfactory
operation and long life for your Fully Balanced Integrated Amplifier
and related system components.

Krell FBI

5

Revolutionary Krell CAST Technology

Current Audio Signal Transmission, termed CAST, is a revolutionary
method of connecting analog audio components for unparalleled sonic
performance. Innovative engineering combines the new Krell CAST cir­cuitry with existing Krell Current Mode technology to create entire
CAST systems that reproduce music with incredible range, tonality,
and precision.

The Voltage Signal Transmission
and the Traditional Audio System

Traditionally, signal is transmitted in the voltage domain between two
components. In an audio system, each component is a discrete entity
with unique characteristics that act upon the musical signal independ­ently. Each component is unaware of the other components in the sys­tem. The cables that connect the components also have their own
electrical characteristics, which affect the sonic presentation of the
entire system. CAST transmission unifies individual components and
interconnects into an electrically-linked whole. The original signal
remains unaltered from source to speaker.

CAST Basics

Here is how a CAST audio system works. Internally
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. W
properties and signal transmission aberrations between components
are eliminated. Cable impedances and their effects on the transmitted
signal are non-existent.

, each CAST source

ith CAST, circuit board

How CAST and Krell Current Mode Interact

While CAST is a new method of transferring the musical signal be­tween components, its origin stems from Krell Current Mode, the tech­nology developed to transfer the musical signal within a component.
CAST combined with Krell Current Mode takes circuitry signal trans­mission to the next evolutionary level. In essence, Krell Current Mode

6 Krell FBI

evolutionary Krell CAST Technology,

R

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
width increases up to an order of magnitude greater than their voltage
based counterparts. This dramatic increase in circuit bandwidth deliv­ers near perfection in the audible band that typically suffers from phase
distortions in voltage circuits.

CAST Cable Construction

A CAST system uses cables manufactured by Krell and other manu­facturers specially licensed by Krell. Thin and flexible CAST cables are
constructed with the same build quality as other Krell components and
are aesthetically matched to the components that Krell manufactures.
An all-metal body and locking connectors with gold contacts are part
of the standard no-compromise specification developed for every
CAST cable made.

continued

single global circuit. Krell Current Mode technology enjoys band-

Evolution CAST

By employing r
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.

evolutionary current mirror circuitry, the Evolution 222

The Best Musical Performance

When you operate a CAST system, you will hear significant improve­ments in every performance area: speed, precision, dynamic range,
depth and width of the sound stage, transient impact, tonal balance,
harmonic distortion, and more. The goal for CAST is the same compa­ny goal used for all Krell products. Krell strives for the delivery of the
best performance of a musical event for you, using the full expression
of technology to date.

Krell FBI 7

Definition of Terms

Following are the definitions of key terms used in your owner’s
reference manual.

CONFIGURATIONS

INPUT AND OUTPUT
CONNECTIONS

Theater Throughput

Theater Throughput is a Krell configuration option that allows the
signal from a surround preamp/processor to pass through a Krell
preamplifier or integrated amplifier input at unity gain and sus­pends operation of the preamp volume control. When Theater
Throughput is employed, control of the volume is accomplished
through the home theater processor.

Balanced

A symmetrical input or output circuit that has equal impedance
from both input terminals to a common ground reference point.
The industr

y standard for professional and sound r

lations, balanced connections have 6 dB mor

ecording instal-

e gain than single­ended connections and allow the use of long interconnect cables.
Balanced connections are completely immune to induced noise
from the system or the envir

CAST and Evolution CAST

Krell Current Audio Signal Transmission, or CAST, is a proprietary Krell
circuit technology for connecting analog components, transmitting the
audio waveform between components in the current domain rather than
in the voltage domain. The speed and bandwidth pr
CAST and its circuitry update, Evolution CAST, yield accurate, realistic

oduction, enabling connected components to per

music r
they are all part of a single circuit.

epr

onment.

ovided by Krell

form as if

Single-ended

A two-wire input or output circuit. Use care when using single­ended connections as the ground connection is made last and
broken first. Turn the system off prior to making or breaking sin­gle-ended connections. Single-ended connections are not recom­mended for connections r

8 Kr

equiring long cable r

uns.

ell FBI

efinition of Terms,

D

continued

OPERA TION

TECHNOLOGY

Off

The component is off when the AC power cord is unplugged from
the wall receptacle.

Stand-by Mode

A low power consumption status that keeps the audio circuits at
idle. When you plug the AC power cord into the wall receptacle,
and turn on the rear panel breaker switch, the red stand-by LED
illuminates. The component is now ready to be switched to the
operational mode. Krell recommends leaving the component in
the stand-by mode when it is not playing music.

Operational Mode

When the component is in the stand-by mode, and you press the
power button on the front panel or the power key on the remote
control, the blue power LED illuminates. The component is in the
operational mode and is ready to play music.

Krell Current Mode

A proprietar

y Krell circuit topology in which the audio gain stages
of a component operate in the current rather than voltage domain.
This unique technology pr

ovides the component with exceptional

speed and a wide bandwidth.

Krell FBI

See also Revolutionary Krell CAST Technology, on pages 6-7.

9