Krell Industries Showcase 5 User manual

Instructions for Use
Owner’s Reference
THE LEADER IN AUDIO ENGINEERING
Showcase 7
Showcase 6
Showcase 5
Multichannel Amplifier

©2002 by Krell Industries, Inc. All rights reserved P/N 306039
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. Krell
Current Mode™ is a trademark of Krell Industries, Inc. All other trademarks and tradenames are registered
to their respective companies.
Showcase 7
Showcase 6
Showcase 5
Multichannel Amplifier
Instructions for Use
v 02.1
Krell Industries, Inc.
45 Connair Road
Orange, CT 06477-3650 USA
TEL [phone]
FAX [phone]
E-MAIL [email protected]
WEBSITE http://www.krellonline.com
This product complies with the EMC directive (89/336/EEC) and the low-voltage
directive (73/23/EEC).
The amplifier must be placed on a firm, level surface where it is not exposed to
dripping or splashing.
The ventilation grids on the top, bottom, and sides of the amplifier must be unob-
structed at all times during operation. Do not place flammable material above or
beneath the amplifier.
Contact your authorized Krell dealer, distributor, or Krell before using any devices
designed to alter or stabilize the AC power for the Showcase Amplifier.
Before connecting the Showcase Amplifier, make sure the amplifier is turned off
and any output device (such as a preamplifier) is in mute or stand-by mode. Make
sure all cable terminations are of the highest quality and free from frayed ends,
short circuits, or cold solder joints.
Use only one input to each amplifier channel at a time.
If the red LED flashes when the amplifier is in the stand-by mode, unplug the
amplifier to reset the protection circuit. Check the loudspeakers and loudspeaker
cables for potential short circuits before reconnecting the amplifier to your system.
THERE ARE NO USER SERVICEABLE PARTS INSIDE THE PREAMPLIFIER
Please contact your authorized Krell dealer, distributor, or Krell if you have any ques-
tions not addressed in this reference manual.
CONTACT
INFORMATION
WARNINGS

Contents
Krell Showcase Amplifier iii
INTRODUCTION 1
DEFINITION OF TERMS 2
UNPACKING 3
PLACEMENT 4
AC Power Guidelines 4
FRONT PANEL DESCRIPTION 6
BACK PANEL DESCRIPTION 8
CONNECTING THE SHOWCASE AMPLIFIER
TO YOUR SYSTEM 10
Input and Output Connections 10
AMPLIFIER OPERATION 12
On/Off and Operation 12
TROUBLESHOOTING SYSTEM NOISE 13
QUESTIONS AND ANSWERS 14
WARRANTY 15
RETURN AUTHORIZATION PROCEDURE 16
SPECIFICATIONS 17
Page

iv Krell Showcase Amplifier
FIGURE 1 The Showcase Amplifier Front Panel 5
FIGURE 2 The Showcase Amplifier Back Panel 7
Illustrations
Page

Krell Showcase Amplifier 1
Thank you for your purchase of a Krell Showcase Amplifier.
The Showcase Amplifier is a flexible design that delivers five, six,
or seven channels of amplification. All three configurations include
input and output connections for all seven channels. The amplifiers
differ only by how many channels are housed within the amplifier.
A Showcase 5 includes five amplifier channels, a Showcase 6
includes six amplifier channels, and a Showcase 7 includes seven
amplifier channels. The Showcase 5 and Showcase 6 may be
upgraded with additional channels, up to seven. The Showcase
Amplifier has balanced and single-ended inputs for compatibility
with other components. The amplifiers can be operated using the
12 VDC power on/off (12 V trigger) signals from other components.
The Showcase Amplifier is versatile, fitting a variety of installations
including rack-mounted and inside cabinetry.
Please contact your Krell-authorized dealer or distributor for infor-
mation on upgrading your amplifier to six or seven channels.
This reference manual contains important information on place-
ment, installation, and operation of the Showcase Amplifier. Please
read this information carefully. A thorough understanding of these
details helps ensure satisfactory operation and long life for your
Showcase Amplifier and related system components.
Introduction

2Krell Showcase Amplifier
Following are the definitions of key terms used in your owner’s ref-
erence manual.
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 con-
nections and allow the use of long interconnect cables. Balanced
connections are less susceptible than single-ended connections to
induced noise from the system or the environment.
Single-ended
A two-wire input or output circuit. Use care when using single-
ended connections as the ground connection is made last and bro-
ken first. Turn the system off prior to making or breaking single-
ended connections. Single-ended connections are not recommend-
ed for connections requiring long cable runs.
Off
When the AC power cord is not plugged into the wall, the red
stand-by LED is not illuminated and the component is off.
Stand-by Mode
When the AC power cord is plugged into the wall, the red stand-by
LED illuminates, indicating that the component is in the stand-by
mode. This low power consumption status keeps the audio and cir-
cuits at idle. Krell recommends leaving the component in the stand-
by mode when it is not playing music.
Operational Mode
From the stand-by mode, when the power button on the front panel
is pressed and the blue power LED illuminates, the component is in
the operational mode and ready to play music.
Krell Current Mode
A proprietary Krell circuit topology in which the audio gain stages of
a component operate in the current rather than the voltage domain.
This unique technology provides the component with exceptional
speed and a wide bandwidth.
Definition of Terms
INPUT AND OUTPUT
CONNECTIONS
OPERATION
TECHNOLOGY

Unpacking
Krell Showcase Amplifier 3
1. Open the shipping box, and remove the top layer of foam. The
following items are visible:
1 Showcase Amplifier
1 Accessory Kit containing:
1 AC power cord
1 12 VDC output (12 V trigger) cable
1 spare AC mains fuse
1 10 A slow-blow fuse for 100 –120 VAC
1 5 A slow-blow fuse for 220 –240 VAC
1 packet containing the owner’s reference manual and the
warranty registration card.
Two people are needed to remove the amplifier from the shipping
box.
2. Grasp the underside of the amplifier and lift it straight out of the
shipping box.
3. Place the amplifier in a safe location and remove the protective
plastic wrapping.
If any of these items are not included in the shipping box, please contact
your authorized Krell dealer, distributor, or Krell for assistance.
Save all packing materials. If you ship your amplifier in the future, repack
the unit in its original packaging to prevent transit damage. See Return
Authorization Procedure, on page 16, for more information.
IMPORTANT
Notes

4Krell Showcase Amplifier
Before you integrate the Showcase Amplifier into your system,
review the following guidelines to choose the location for the com-
ponent. This will facilitate a clean, trouble-free installation.
The Showcase Amplifier requires at least two inches (5 cm) of
clearance on each side and at least two inches (5 cm) of clearance
above and below the component to provide adequate ventilation.
The Showcase Amplifier does not require any type of special rack
or cabinet for installation. For the dimensions of your amplifier see
Specifications, on page 17.
Place the amplifier as close to the loudspeakers as possible and
keep the loudspeaker cable length to a minimum. Loudspeaker
cable adds impedance to the load the amplifier must drive, regard-
less of the cable’s gauge. Krell amplifiers drive the lowest imped-
ances with ease, but long loudspeaker cables reduce the maximum
power that is delivered to the loudspeakers.
Placement
Krell recommends operating the Showcase Amplifier from a dedi-
cated 15-amp AC power line. Please contact your Krell dealer, dis-
tributor, or Krell before using any devices designed to alter or stabi-
lize the AC power for the Showcase Amplifier.
AC POWER
GUIDELINES

1 Power Button
2 Stand-by LED
3 Power LED
SHOWCASE
AMPLIFIER
2 13
STAND-BY
POWER
Figure 1 The Showcase Amplifier Front Panel

The Showcase Amplifier front panel provides power on and indi-
cates operating status.
1 Power Button
Use this button to switch the Showcase Amplifier power between
the stand-by and the operational modes and also to switch the 12
VDC output (12 V trigger) on and off.
2 Stand-by LED
The red stand-by LED illuminates when the AC power cord is
plugged into the wall. The stand-by LED flashes when the protec-
tion circuit is activated.
3 Power LED
The blue power LED illuminates when the amplifier is in the opera-
tional mode.
6Krell Showcase Amplifier
Front Panel Description
See Figure 1 on page 5