Krell Industries DVD Standard User manual

Instructions for Use
Owner’s Reference
THE LEADER IN AUDIO ENGINEERING
Theater Amplifier
Standard
Multichannel Amplifier

Theater Amplifier
Standard
Multichannel Amplifier
Instructions for Use
v 02.0
rell 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 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. Multi Amp Throughput™ and Krell Current Mode™ are trademarks of Krell Industries, Inc. All other
trademarks and tradenames are registered to their respective companies.
This product complies with the EMC directive (89/336/EEC) and the low-voltage directive (73/23/EEC).
WARNINGS
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 unobstructed 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 stabi-
lize the C power for the Theater mplifier Standard.
Before connecting the Theater mplifier Standard, 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 set of inputs to the amplifier at a time.
Make sure that only one switch on an input switch bank is in the up (on) position at one time.
Do not connect the multichannel (DB-25) input and the single-ended or balanced inputs at the same time.
THERE ARE NO USER SERVICEABLE PARTS INSIDE ANY KRELL PRODUCT.
Please contact your authorized Krell dealer, distributor, or Krell if you have any questions not addressed in
this reference manual.
©2001 by Krell Industries, Inc. All rights reserved P/N 305221

Krell Theater Amplifier Standard iii
Contents Page
INTRODUCTION 1
DEFINITION OF TERMS 2
UNPACKING 4
PLACEMENT 5
AC Power Guidelines 5
FRONT PANEL DESCRIPTION: THEATER AMPLIFIER STANDARD 7
BACK PANEL DESCRIPTION: THEATER AMPLIFIER STANDARD 9
CONNECTING THE THEATER AMPLIFIER STANDARD TO YOUR SYSTEM 11
Input and Output Connections 11
AMPLIFIER OPERATION 13
On/Off and Operation 13
Using a Dedicated Wall Switch 13
TROUBLESHOOTING SYSTEM NOISE 14
RECONFIGURATION OPTIONS FOR THE THEATER AMPLIFIER STANDARD 15
To Safely Access the Input Switch Banks 15
Amplifier Factory Default Settings 18
Reconfiguring the Theater Amplifier Standard for MAT Operation 18
Reconfiguring the Theater Amplifier Standard for Bridged Operation 22
Reconfiguring the Theater Amplifier Standard
for Combined MAT and Bridged Operation 24
Example of a Connection Scenario: Multi-power Mode 25
QUESTIONS AND ANSWERS 27
WARRANTY 28
RETURN AUTHORIZATION PROCEDURE 29
SPECIFICATIONS 30

iv Krell Theater Amplifier Standard
Illustrations Page
FIGURE 1 The Theater Amplifier Standard Front Panel 6
FIGURE 2 The Theater Amplifier Standard Back Panel 8
FIGURE 3 The Theater Amplifier Standard Input Circuit Board
Factory Default Settings 16
FIGURE 4 Reconfiguring the Theater Amplifier Standard for MAT Operation 17
FIGURE 5 Reconfiguring the Theater Amplifier Standard for Bridged Operation 21
FIGURE 6 Reconfiguring the Theater Amplifier Standard for Combined MAT
and Bridged Operation 23

Krell Theater Amplifier Standard 1
Introduction
Thank you for your purchase of the Krell Theater Amplifier Standard Multichannel
Amplifier.
The Theater Amplifier Standard provides substantial five-channel output power that
delivers realistic music reproduction at an exceptional value. The amplifier channels
can be customized quickly through a series of switches. Optional system configurations
include bridged operation and a multi-power mode using the Multi Amp Throughput
(MAT) feature. The Theater Amplifier Standard has balanced and single-ended inputs
for compatibility with other components. The multichannel (DB-25) input also allows you
to integrate the amplifier easily and seamlessly into home theater systems. The
amplifier can be operated using the 12 VDC power on/off (12 V trigger) signals from
other components. The Theater Amplifier Standard is versatile, fitting a variety of
installations including rack-mounted and inside cabinetry.
This reference manual contains important information on placement, installation, and
operation of the Theater Amplifier Standard. Please read this information carefully. A
thorough understanding of these details helps ensure satisfactory operation and long
life for your Theater Amplifier Standard and related system components.

2Krell Theater Amplifier Standard
Definition of Terms
Following are the definitions of key terms used in your owner’s reference manual.
CONFIGURATIONS
Bridging
A method of linking two amplifier channels by distributing the speaker load between the
positive binding posts. Bridging the channels quadruples the power rating at 8 Ohms.
Bridged configurations should not be used with loads under 4 Ohms.
Krell Multi Amp Throughput (MAT)
An internal configuration option that sends the same music signal to all amplifier
channels using one balanced or single-ended connection. MAT reduces installation
complexity and cabling requirements in systems containing multiple amplifiers. MAT
also allows a variety of connection scenarios, including powering loudspeakers that
have two sets of binding posts and independently powering multiple pairs of stereo
loudspeakers to extend the listening environment throughout your home.
INPUT AND OUTPUT CONNECTIONS
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. Balanced
connections are less susceptible than single-ended connections to induced noise from
the system or the environment.
Multichannel (DB-25)
A balanced input or output circuit that allows for the simultaneous connection of all
audio outputs plus one 5 VDC (5 Volt trigger) via a single cable. DB-25 inputs and
outputs are becoming popular for connecting an audio/video surround sound processor
and power amplifiers, simplifying the integration of the two components into your
system.
Single-ended
A two-wire input or output circuit. Use care when using single-ended 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 requiring long cable runs.

Krell Theater Amplifier Standard 3
Definition of Terms, continued
OPERATION
Off
When the back panel power switch is in the down (off) position and the red stand-by
LED turns off, the component is off.
Stand-by Mode
When the AC power cord is plugged into the wall and the back panel power switch is in
the up (on) position, 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
regulator circuits 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 indicator illuminates, the component 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 the voltage domain. This unique technology provides
the component with exceptional speed and a wide bandwidth.

4Krell Theater Amplifier Standard
Unpacking
Open the shipping box, which contains:
1 amplifier unit (packed in foam end-caps)
1 AC power cord
5 AGC-12 (12-amp) speaker fuses
1 12 VDC output (12 V trigger) cable
1 T-15 Torx wrench
1 packet containing the owner’s reference manual
and the warranty registration card.
IMPORTANT
Two people are needed to remove the amplifier from the shipping box.
1. One person grasps the underside of the foam end-caps at one end of the amplifier;
at the same time, the second person grasps the underside of the foam end-caps at
the other end of the amplifier.
2. Slowly lift the amplifier straight out of the shipping box.
3. Place the amplifier in a safe location and remove the protective plastic wrapping.
Notes
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 29, for more information.

Krell Theater Amplifier Standard 5
Placement
Before you integrate the Theater Amplifier Standard into your system, review the
following guidelines to choose the location for the component. This will facilitate a
clean, trouble-free installation.
The Theater Amplifier Standard 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 Theater Amplifier Standard does not require any type of special rack or cabinet for
installation. For the dimensions of your amplifier see
Specifications ,on page 30.
Place the amplifier as close to the loudspeakers as possible and keep the speaker
cable length to a minimum. Speaker cable adds impedance to the load the amplifier
must drive, regardless of the cable’s gauge. Krell amplifiers drive the lowest
impedances with ease, but long speaker cables reduce the maximum power that is
delivered to the loudspeakers.
AC POWER GUIDELINES
Krell recommends operating the Theater Amplifier Standard from a dedicated 20-amp
AC power line. The Theater Amplifier Standard should be used only with the AC power
cord supplied. Please contact your Krell dealer, distributor, or Krell before using any
devices designed to alter or stabilize the AC power for the Theater Amplifier Standard.

1 Power Button 2 Stand-by LED 3 Power Indicator
13 2
Theater Amplifier Standard
Figure 1 The Theater Amplifier Standard Front Panel

Krell Theater Amplifier Standard 7
Front Panel Description: Theater Amplifier Standard
See Figure 1 on page 6
The Theater Amplifier Standard front panel provides power on and indicates operating
status.
1 Power Button
Use this button to switch the Theater Amplifier Standard power between the stand-by
and the operational modes and also to switch the 12 VDC output (12 V trigger) on and
off.
2Stand-by LED
The red stand-by LED illuminates when the AC power cord is plugged into the wall and
the back panel power switch is in the up (on) position.
3 Power Indicator
The blue power indicator illuminates when the amplifier is in the operational mode.

Balanced Inputs 4 Inputs 1-5 Single-ended Inputs 5 Inputs 1-5 Multichannel Input 6 Multichannel Input
Amplifier Channel Outputs 7 Outputs 1-5 Fuses 8 AGC-12 Fuses
max.
INPUT 1
OUT
IN
12VDC
(LEFT)
OUTPUT 1
30 mA
MADE IN USA
50/ 0 Hz
INPUT 2INPUT 3
OUTPUT 2
(CENTER)(RIGHT)
OUTPUT 3
INPUT 4INPUT 5
OUTPUT 4
OUTPUT 5
(RIGHT SURROUND) (LEFT SURROUND)
Theater Amplifier Standard
NO USER SERVICEABLE PARTS INSIDE
KRELL INDUSTRIES, INC. 45 CONNAIR ROAD ORANGE, CT 0 477-3 50 USA
AGC-12
AGC-12AGC-12 AGC-12 AGC-12
5 4 8 7
6 9
12
10
11
Ð
+
BRIDGE
Ð
BRIDGE
+
Remote Connections
9 12 VDC Remote Power Out
10 12 VDC Remote Power In Power 11 AC Power Cord 12 Back Panel Power Switch
Figure 2 The Theater Amplifier Standard Back Panel

Krell Theater Amplifier Standard 9
Back Panel Description: Theater Amplifier Standard
See Figure 2 on page 8
The Theater Amplifier Standard back panel provides connections for all inputs and
outputs, remote connection input and output links, and AC power supply. See
Reconfiguration Options for the Theater Amplifier Standard, on pages 15-26, for
information on optional system configurations and amplifier channel output
connections.
Balanced Inputs
4 Inputs 1-5
The Theater Amplifier Standard has five channel inputs for output devices with
balanced XLR connectors.
Single-ended Inputs
5 Inputs 1-5
The Theater Amplifier Standard has five channel inputs for output devices with single-
ended RCA connectors.
Multichannel Input
6 Multichannel Input
The Theater Amplifier Standard has one DB-25 input, for connecting to the DB-25
output of a preamp/processor. The DB-25 input incorporates all five channels plus a
5 VDC (5 Volt trigger), allowing you to send all audio signals and turn the amplifier on
and off via a single cable.
IMPORTANT
Do not connect the multichannel (DB-25) input and the single-ended or balanced inputs
at the same time.
Use only one set of inputs to the amplifier at a time.
Amplifier Channel Outputs
7 Outputs 1-5
The Theater Amplifier Standard has five amplifier channel outputs. The loudspeaker
binding post terminals accept spade lugs, bare wire, or pins. Use the red terminal for
the positive connection and the black terminal for the negative connection.
IMPORTANT
Tighten loudspeaker binding posts by hand only.

10 Krell Theater Amplifier Standard
Back Panel Description, continued
Fuses
8 AGC-12 Fuses
The AGC 12 Amp loudspeaker fuses protect the Theater Amplifier Standard against
short circuits at the amplifier outputs.
Back Panel Remote Connections
9 12 VDC Remote Power Out
The Theater Amplifier Standard is equipped with an output that sends 12 VDC power
on/off (12 V trigger) signals to other Krell components and other devices that
incorporate a 12 V trigger.
Notes
When the component is in the operational mode, the 12 VDC Out provides 12 V of DC
output. When the component is in the stand-by mode or off, the DC output is 0 V.
12 VDC Out (12 V trigger) current is limited to 30 mA.
10 12 VDC Remote Power In
The Theater Amplifier Standard is equipped with an input that receives 12 VDC power
on/off (12 V trigger) signals from other Krell components and other devices that
incorporate a 12 V trigger. This allows you to turn the Theater Amplifier Standard on
and off using a Krell or other component in a custom installation.
Note
Consult the owner’s manual of each component used in a custom installation to take full
advantage of the Theater Amplifier Standard
remote capability.
Power
11 IEC Connector
The Theater Amplifier Standard is equipped with a standard IEC power connector for
use with the AC power cord.
12 Back Panel Power Switch
Use this switch to turn the Theater Amplifier Standard from off to the stand-by mode.

Krell Theater Amplifier Standard 11
Connecting the Theater Amplifier Standard
to Your System
INPUT AND OUTPUT CONNECTIONS
The Theater Amplifier Standard is equipped with balanced and single-ended inputs and
a multi-channel DB-25 connector.
Krell recommends using balanced interconnect cables. Balanced interconnect cables
not only can minimize sonic loss but are also immune to induced noise, especially with
installations using long cables. Balanced connections have 6 dB more gain than single-
ended connections. When level matching is critical, please keep this gain value in mind.
The Theater Amplifier Standard is shipped with shorting pins in the XLR inputs. These
pins should remain in the XLR inputs if the amplifier is operating in the single-ended
mode. When the shorting pin is inserted, pins 1 (lower left) and 3 (top) are shorted
together. Remove the shorting pins to connect the amplifier for balanced or multi-
channel DB-25 operation.
The XLR pin configuration is described below:
Pin 1 Shield (ground)
Pin 2 Non-inverting (hot) (0°)
Pin 3 Inverting (cold) (180°)
Follow these steps to connect the Theater Amplifier Standard to your system.
1. Make sure all power sources and components are off before connecting inputs and
outputs.
2. Neatly organize the wiring between the amplifier and all system components.
Separate AC wires from audio cables to prevent hum or other unwanted noise from
being introduced into the system.
3. Connect the interconnect cables from your source components to the amplifier
inputs using the balanced (4) or single-ended (5) inputs located on the back panel.
The balanced inputs use three-pin XLR connectors; the single-ended inputs use
RCA connectors.
or

12 Krell Theater Amplifier Standard
Connecting the Theater Amplifier Standard , continued
Use the multichannel (DB-25) connector to simplify the integration of the Theater
Amplifier Standard into your system:
Connect the DB-25 output on your preamp/processor to the DB-25 multichannel input
(6) on the back panel of the Theater Amplifier Standard. The DB-25 cable
simultaneously transmits audio outputs and Trigger 1 signals from the DB-25 output of
the Krell Home Theater Standard Surround Preamp/processor to all inputs and to a 5
VDC (5 Volt trigger) on the Theater Amplifier Standard via the DB-25 input.
Note
If you are connecting the Home Theater Standard and the Theater Amplifier Standard
via a DB-25 connector, you need to configure Trigger 1 on the Home Theater Standard
before operating the Theater Amplifier Standard.
IMPORTANT
Do not connect the multichannel (DB-25) input and the single-ended or balanced inputs
at the same time.
Use only one set of inputs to the amplifier at a time.
Remove the shorting pins in the XLR inputs when using the DB-25 multichannel input.
4. Connect the loudspeaker cables to the Theater Amplifier Standard channel output
binding posts (7) located on the back panel.
The binding post terminals accept spade lugs, bare wire, or pins. Use the red terminal
for the positive connection and the black terminal for the negative connection.
IMPORTANT
Tighten loudspeaker binding posts by hand only.
5. Insert the AC power cord into the IEC connector (11) on the Theater Amplifier
Standard. Insert the other end of the AC power cord into the AC wall outlet.
The amplifier is now ready for operation. See
Amplifier Operation, on page 13. You
can also reconfigure the amplifier for Multi Amp Throughput or Bridged Operation. See
Reconfiguration Options for the Theater Amplifier Standard, on page 15.

Krell Theater Amplifier Standard 13
Amplifier Operation
ON/OFF AND OPERATION
When powering up your system, turn amplifiers on last. When powering down your
system, turn amplifiers off first. The procedures for amplifier operation follow.
1. Plug the end of the AC power cord (11) into the AC wall outlet.
2. Push the back panel power switch (12) up (on). You will hear two clicks, then the
red stand-by LED (2) illuminates.
There is a brief delay before the component can be put in the operational mode.
Please wait approximately 10 seconds.
3. Press the power button (1) on the front panel. The blue power indicator (3)
illuminates and you hear a click. The amplifier is in the operational mode.
Krell recommends leaving the Theater Amplifier Standard in the stand-by mode unless
you will not be playing music for a long time.
IMPORTANT
Always turn the amplifier off before changing input connections, and mute or fully
attenuate the preamplifier level when switching sources.
The Theater Amplifier Standard has tremendous reserves of power and safely drives
loudspeakers to extremely high sound pressure levels. However, use care when setting
high playback levels and lower the volume level at any sign of loudspeaker distress.
USING A DEDICATED WALL SWITCH
The Theater Amplifier Standard can also be powered on from an AC wall receptacle
with a dedicated switch, rather than from the front panel power button. Please contact
your authorized Krell dealer, distributor, or Krell for more information before you
connect the Theater Amplifier Standard to a dedicated AC wall outlet with a switch.

14 Krell Theater Amplifier Standard
Troubleshooting System Noise
When you mix and match high-performance audio components, each with its own
ground potential, a low frequency hum may occur in one or all loudspeakers. If this
happens when you place the Theater Amplifier Standard into your system, follow these
simple troubleshooting steps:
1. Check that all input and output connections are of sound construction.
2. With the amplifier off, remove all the interconnect cables, then turn the amplifier on.
If the hum disappears, turn the amplifier off and reinsert one of the interconnect
cables. Turn the amplifier back on.
3. If the hum reappears with the interconnect cable reinserted, the cable may need to
be replaced. Turn the amplifier off and connect a different interconnect cable to the
same location. Turn the amplifier back on.
4. If the hum disappears with the interconnect cable reinserted, that cable most likely
is sound.
5. Turn the amplifier off, disconnect the interconnect cable, and re-connect one of the
other interconnect cables.
6. Repeat steps 3 through 5 until you have checked each interconnect cable.
7. If all the interconnect cables appear to be sound, and you still have hum, you may
be experiencing a ground loop. Please contact your authorized Krell dealer,
distributor, or Krell for suggestions on how to eliminate it.

Krell Theater Amplifier Standard 15
Reconfiguration Options for the
Theater Amplifier Standard
The Theater Amplifier Standard offers a number of options for configuring your amplifier
output and is unique in that it allows you to bridge and use Multi Amp Throughput at the
same time.
Multi Amp Throughput (MAT) is an internal connection option for the Theater
Amplifier Standard that lets you send the same music signal to all amplifier channels
using one balanced or single-ended connection. MAT reduces installation complexity
and cabling requirements in systems containing multiple amplifiers.
Bridging allows you to reconfigure four of the Theater Amplifier Standard channels to
operate as two combined amplifier channels. The bridged amplifier channels each
deliver 800 Watts into an 8 Ohm load. The remaining unbridged amplifier channel can
be connected to a separate loudspeaker.
IMPORTANT
Removing the cover to reconfigure for MAT or for bridged operation is the ONLY
instance you are authorized to remove the cover of ANY Krell component without
voiding your Warranty. For more information on product limitations and restrictions,
see Warranty, on page 28.
TO SAFELY ACCESS THE INPUT SWITCH BANKS
Read the following important instructions to safely remove the amplifier cover to
reconfigure the Theater Amplifier Standard.
Tool needed: T-15 Torx wrench
1. Unplug the AC power cord from AC power.
2. Krell suggests removing jewelry before reconfiguring your amplifier. Rings,
necklaces, bracelets, and other metal jewelry can conduct an electrical charge.
3. Using the T-15 Torx wrench, remove the 12 screws that secure the amplifier cover.
4. Carefully remove the cover.
5. Locate the green input circuit board, white input switches, and red input switch
banks, at the rear of the amplifier.
6. Reconfigure your amplifier, using the scenarios described below.

Figure 3 The Theater Amplifier Standard Input Circuit Board Factory Default Settings
34512
O
N3 4 51 2
O
N3 4 51 2
O
N3 4 51 2
O
N34512
O
N
34512
O
N
1 1
Switch Up (On) Switch Down (Off) Bridge Switch Up (On) Bridge Switch Down (Off) Input Switch Bank
S7
S1
Bridge
Channel 1 Input Channel 2 Input Channel 3 Input Channel 4 Input Channel 5 InputBridge
DB-25 Inputs: 1: Left 2: Center 3: Right 4: Left Surround 5: Right Surround
MT1
J14 J11 J16 J13S4 S6 S5 J12S3
S2
Input Circuit Board