Krell Theater Amplifier Standard Reference

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

Krell Industries, Inc.
45 Connair Road
Orange, CT 06477-3650 USA

TEL [phone]
FAX [phone]
E-MAIL [e-mail]
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 AC power for the Theater Amplifier Standard.
Before connecting the Theater Amplifier 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.

2

Krell 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.

4

Krell 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.

2 Stand-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

50/60 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 06477-3650

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 single­ended 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 single­ended 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 multi­channel 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

3 4 51 2

O

N

3 4 51 2

O

N

3 4 51 2

O

N

3 4 51 2

O

N

3 4 51 2

O

N

3 4 51 2

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

Figure 4 Reconfiguring the Theater Amplifier Standard for MAT Operation

3 4 51 2

O

N

3 4 51 2

O

N

3 4 51 2

O

N

3 4 51 2

O

N

3 4 51 2

O

N

3 4 51 2

O

N

1 1

Switch Up (On)

Switch Down (Off)

Bridge Switch Up (On)

Bridge Switch Down (Off)

Input Switch Bank

3 4 51 2

O

N

3 4 51 2

O

N

3 4 51 2

O

N

3 4 51 2

O

N

3 4 51 2

O

N

1 1

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

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

SCENARIO 1: Send One Input Signal to All Five Output Channels via Input 1

SCENARIO 2: Send One Input Signal to Two Output Channels via Input 1

Input Circuit Board

18

Krell Theater Amplifier Standard

Reconfiguration Options, continued

Accessing the Input Switch Banks, continued

7. After the component is configured, replace the cover and, using the T-15 Torx

wrench, secure all 12 cover screws.

IMPORTANT

Operating the amplifier without the cover properly replaced and secured may void your
Warranty.

AMPLIFIER FACTORY DEFAULT SETTINGS

See Figure 3 on page 16

The amplifier is shipped with input switch banks set to the following factory defaults:

1. For input switch bank 1: switch 1 up (on), other switches down (off).

2. For input switch bank 2: switch 2 up (on), other switches down (off).

3. For input switch bank 3: switch 3 up (on), other switches down (off).

4. For input switch bank 4: switch 4 up (on), other switches down (off).

5. For input switch bank 5: switch 5 up (on), other switches down (off).

RECONFIGURING THE THEATER AMPLIFIER STANDARD
FOR MAT OPERATION

Send One Input Signal to All Five Output Channels via Input 1
(Scenario 1)

See Figure 4 on page 17

1. Push switch 1 up (on) for all input switch banks.

2. Push switches 2-5 down (off) for all input switch banks.

Although Figure 4 illustrates sending the signal from input 1 to all five channels, you
can send the signal from any of the inputs, depending on your preferences.

To Send One Input Signal to all Five Output Channels via Input 2

Not illustrated

1. Push switch 2 up (on) for all input switch banks.

2. Push switches 1, 3, 4, and 5 down (off) for all input switch banks.

Krell Theater Amplifier Standard 19

Reconfiguration Options, continued

To Send One Input Signal to all Five Output Channels via Input 3

Not illustrated

1. Push switch 3 up (on) for all input switch banks.

2. Push switches 1, 2, 4, and 5 down (off) for all input switch banks.

To Send One Input Signal to all Five Output Channels via Input 4

Not illustrated

1. Push switch 4 up (on) for all input switch banks.

2. Push switches 1, 2, 3, and 5 down (off) for all input switch banks.

To Send One Input Signal to all Five Output Channels via Input 5

Not illustrated

1. Push switch 5 up (on) for all input switch banks.

2. Push switches 1, 2, 3, and 4 down (off) for all input switch banks.

Connecting the Theater Amplifier Standard Reconfigured for MAT
(Scenario 1)

IMPORTANT

Do not use the multi-channel (DB-25) input if you have reconfigured the

Theater

Amplifier Standard

for MAT operation.

1. Connect the cable from your source device to the balanced or single-ended input

you have selected to receive the signal. (For example, the switch settings shown in
Figure 4 are for using input 1.)

2. Connect each amplifier channel output to a separate loudspeaker.

Send One Input Signal to Two Output Channels via Input 1
(Scenario 2)

See Figure 4 on page 17

1. For input switch bank 1, push switch 1 up (on).

2. For input switch bank 2, push switch 1 up (on).

20

Krell Theater Amplifier Standard

Reconfiguration Options, continued

3. For input switch banks 1 and 2, push switches 2-5 down (off).

4. For input switch bank 3, push switch 3 up (on) and switches 1, 2, 4, and 5 down

(off).

5. For input switch bank 4, push switch 4 up (on) and switches 1, 2, 3, and 5 down

(off).

6. For input switch bank 5, push switch 5 up (on) and switches 1, 2, 3, and 4 down

(off).

Send One Input Signal to Two Output Channels via Input 3

Not illustrated

1. For input switch bank 3, push switch 3 up (on).

2. For input switch bank 4, push switch 3 up (on).

3. For input switch banks 3 and 4, push switches 1, 2, 4, and 5 down (off).

4. For input switch bank 1, push switch 1 up (on) and switches 2, 3, 4, and 5 down

(off).

5. For input switch bank 2, push switch 2 up (on) and switches 1, 3, 4, and 5 down

(off).

6. For input switch bank 5, push switch 5 up (on) and switches 1, 2, 3, and 4 down

(off).

IMPORTANT

Make sure all bridging switches are down (off) unless you are bridging amplifier
channels.

Connecting the Theater Amplifier Standard Reconfigured for MAT
(Scenario 2)

IMPORTANT

Do not use the multichannel (DB-25) input if you have reconfigured the

Theater

Amplifier Standard

for MAT operation.

1. Connect the cable from your source device to the balanced or single-ended input

you have selected to receive the signal.

2. Connect the selected amplifier channel outputs to separate loudspeakers.

Figure 5 Reconfiguring the Theater Amplifier Standard for Bridged Operation

3 4 51 2

O

N

3 4 51 2

O

N

3 4 51 2

O

N

3 4 51 2

O

N

3 4 51 2

O

N

3 4 51 2

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

Bridge Channels 1 and 2 and Bridge Channels 4 and 5

Input Circuit Board

22

Krell Theater Amplifier Standard

Reconfiguration Options, continued

RECONFIGURING THE THEATER AMPLIFIER STANDARD
FOR BRIDGED OPERATION

Bridge Channels 1 and 2 and Bridge Channels 4 and 5

See Figure 5 on page 21

Note

Channel 3 cannot be bridged.

To bridge channels 1 and 2:

1. For input switch bank 1, push switch 1 up (on).

2. For input switch bank 2, push switch 1 up (on).

3. Push bridge switch up (on) between input switch banks 1 and 2.

Note

Input 1 is selected in the above example.

To bridge channels 4 and 5:

1. For input switch bank 4, push switch 4 up (on).

2. For input switch bank 5, push switch 4 up (on).

3. Push bridge switch up (on) between input switch banks 4 and 5.

Note

Input 4 is selected in the above example.

Connecting the Theater Amplifier Standard Reconfigured
for Bridged Operation

1. Connect the cable from your source device to the balanced or single-ended input

you have selected to receive the signal.

2. Connect the positive loudspeaker lead to the red binding post on the corresponding

amplifier channel marked “

BRIDGE +.” Connect the negative loudspeaker lead to the

red binding post on the amplifier channel marked “

BRIDGE -.”

IMPORTANT

Tighten loudspeaker binding posts by hand only.

Note

The unbridged channel may be connected to a separate loudspeaker for normal
operation.

Figure 6 Reconfiguring the Theater Amplifier Standard for Combined MAT and Bridged Operation

3 4 51 2

O

N

3 4 51 2

O

N

3 4 51 2

O

N

3 4 51 2

O

N

3 4 51 2

O

N

3 4 51 2

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

MAT Channels 1, 2, 3; Bridge Channels 4, 5

Input Circuit Board

24

Krell Theater Amplifier Standard

Reconfiguration Options, continued

RECONFIGURING THE THEATER AMPLIFIER STANDARD
FOR COMBINED MAT AND BRIDGED OPERATION

MAT Channels 1, 2, 3 and Bridge Channels 4 and 5

See Figure 6 on page 23

This feature allows you to use MAT and bridging features at the same time. Channels
1, 2, and 3 are connected via MAT, while channels 4 and 5 are bridged.

Reconfiguring Channels 1, 2, and 3 for MAT

1. For input switch banks 1, 2, and 3, push switch 1 up (on).

2. For input switch banks 1, 2, and 3, push switches 2-5 down (off).

Connecting the Channels Configured for MAT

1. Connect the cable from your source device to the balanced or single-ended input

you have selected to receive the signal. (Input 1 is selected in this example.)

2. Connect each selected amplifier channel output to a separate loudspeaker, using

the positive and negative terminals on the loudspeaker binding posts.

IMPORTANT

Tighten loudspeaker binding posts by hand only.

Bridge Channels 4 and 5

1. For input switch bank 4, push switch 4 up (on).

2. For input switch bank 5, push switch 4 up (on).

3. Push bridge switch up (on) between switch banks 4 and 5.

Connecting the Bridged Channels

1. Connect the cable from your source device to the balanced or single-ended input

you have selected to receive the signal. (Input 4 is selected in this example.)

2. Connect the positive loudspeaker lead to the red binding post on the corresponding

amplifier channel marked “

BRIDGE +.” Connect the negative loudspeaker lead to the

red binding post on the amplifier channel marked “

BRIDGE -.”

IMPORTANT

Tighten loudspeaker binding posts by hand only.

+

—

+

—

+

+

+

—

Kitchen (R)

+

—

Living

Room (R)

Patio (R)

Right Amplifier

Right Speakers

Left Amplifier

Left Speakers

Gym (R)

+

—

Bedroom (R)

+

+

+

+

—

+

—

Kitchen (L)

+

—

Living

Room (L)

Patio (L)

+

—

Gym (L)

+

—

Bedroom (L)

———

—

+

—

+

—

+

—

+

—

+

—

—

Krell Theater Amplifier Standard 25

EXAMPLE OF A CONNECTION SCENARIO: MULTI-POWER MODE

Multi-power mode is a possible connection scenario using the Theater Amplifier Standard
Multi Amp Throughput (MAT) feature. With multi-power mode, you can use the Theater
Amplifier Standard reconfigured for MAT to independently power multiple pairs of stereo
loudspeakers, to extend the listening environment throughout your home. When the
Theater Amplifier Standard is reconfigured for MAT, each channel powers an individual
loudspeaker, with one Theater Amplifier Standard dedicated to driving outputs to the left
loudspeakers and one Theater Amplifier Standard driving outputs to the right loudspeakers.

The diagram below illustrates this connection scenario:

Reconfiguration Options, continued

+

—

+

—

Kitchen (L)Patio (L)

—

+

—

+

—

+

—

+

—

+

+

—

+

—

Kitchen (R)Patio (R)

MAT

for

Input 1

MAT

for

Input 4

26 Krell Theater Amplifier Standard

Another option is to use one amplifier to drive speakers in different rooms, using two
channels to drive the left speakers and two channels to drive the right speakers. The
diagram below illustrates this connection scenario:

Reconfiguration Options, continued

Krell Theater Amplifier Standard 27

Questions and Answers

Q. Should I turn the Theater Amplifier Standard

off when not playing music?

A. No. Leave the Theater Amplifier Standard

in the stand-by mode when not playing
music. The stand-by mode avoids cold starts as well as minimizes heat output and
power consumption. Krell recommends turning the amplifier off if you plan to be away
for a period of time, for example, on vacation. See

Amplifier Operation,

on page 13.

Q. When I turn the amplifier on there is a loud hum through the loudspeakers. What
should I do?

A. When a new component is introduced, a low frequency hum may occur in one or
both loudspeakers. Check that all input and output connections and cables are of
sound construction. See

Troubleshooting System Noise

, on page 14. If the

connections and cables are sound, you may be experiencing a ground loop. This can
often be easily eliminated. Please contact your authorized Krell dealer, distributor, or
Krell for suggestions.

Q. When I connect the amplifier to my system using the single-ended inputs, a loud
buzz comes from my loudspeakers. What is it?

A. Check that the shorting pins for the Theater Amplifier Standard

are inserted into the
XLR inputs (the unit is shipped with the pins in place). When using the single-ended
inputs, the shorting pins must be inserted between pins 1 and 3 to keep external noise
from corrupting the signal. For more information, see

Connecting the Theater

Amplifier Standard to Your System

, on page 11.
Q. Can I bridge all the channels on my Theater Amplifier Standard?
A. No. You can bridge four of the amplifier’s five channels: 1, 2, 4, and 5. Channel 3

cannot be bridged.
Q. Will I be able to use the amplifier without reconfiguring the channels for MAT or

bridged operation?
A. Yes. The Theater Amplifier Standard

is shipped from the factory ready to play music.
The default settings allow you to connect each amplifier channel output to a separate
loudspeaker. See

Figure 3,

on page 16. MAT and bridging reconfigurations are

optional.

To register your product
for warranty benefits, please
complete and return the
Warranty Registration Card
enclosed in the shipping box
within 15 days of purchase.
Thank you.

This Krell product has a limited warranty of five years for parts and labor on circuitry. Should
this product fail to perform at any time during the warranty, Krell will repair it at no cost to the
owner, except as set forth in this warranty.

The warranty does not apply to damage caused by acts of God or nature.
The warranty on this page shall be in lieu of any other warranty, expressed or implied, includ-

ing, but not limited to, any implied warranty of merchantability or fitness for a particular purpose.
There are no warranties which exceed beyond those described in this document. If this product
does not perform as warranted herein, the owner’s sole remedy shall be repair. In no event will
Krell be liable for incidental or consequential damages arising from purchase, use, or inability to
use this product, even if Krell has been advised of the possibility of such damages.

Proof of purchase in the form of a bill of sale or receipted invoice substantiating that the unit is
within the warranty period must be presented to obtain warranty service. The warranty begins
on the date of the original retail purchase, as noted on the bill of sale or receipted invoice from
an authorized Krell dealer or distributor. Previously owned equipment, when re-purchased from
an authorized Krell dealer or distributor, has the balance of the original warranty, based on the
original date of manufacture.

The warranty for Krell products is valid only in the country to which they were originally shipped,
through the authorized Krell distributor for that country, and at the factory. There may be restric­tions on or changes to Krell’s warranty because of regulations within a specific country. Please
check with your distributor for a complete understanding of the warranty in your country.

If a unit 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.-based freight forwarder of your choice. Freight and
other charges to ship the unit from the freight forwarder to you are also your responsibility.

Krell is not responsible for any damage incurred in transit. Krell will file claims for damages as
necessary for units damaged in transit to the factory. You are responsible for filing claims for
shipping damages during the return shipment.

Krell does not supply replacement parts and/or products to the owner of the unit. Replacement
parts and/or products will be furnished only to the distributor performing service on this unit on
an exchange basis only; any parts and/or products returned to Krell for exchange become the
property of Krell.

No expressed or implied warranty is made for any Krell product damaged by accident, abuse,
misuse, natural or personal disaster, or unauthorized modification.

Any unauthorized voltage conversion, disassembly, component replacement, perfora­tion of chassis, updates, or modifications performed to the unit will void the warranty.

The operating voltage of this unit is determined by the factory and can only be changed by an
authorized Krell distributor or at the factory. The voltage for this product in the U.S.A. cannot be
changed until six months from the original purchase date.

In the event that Krell receives a product for warranty service that has been modified in any
way without Krell authorization, all warranties on that product will be void. The product will be
returned to original factory layout specifications at the owner’s expense before it is repaired. All
repairs required after the product has been returned to original factory specifications will be
charged to the customer, at current parts and labor rates.

All operational features, functions, and
specifications and policies are subject
to change without notification.

Warranty

28 Krell Theater Amplifier Standard

Krell Theater Amplifier Standard 29

Return Authorization
Procedure

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.com

To return a product to Krell, please follow this procedure so that we
may serve you better:

1. Obtain a Return Authorization Number (R/A number) and ship­ping address from the Krell Service Department.

2. Insure and accept all liability for loss or damage to the product
during shipment to the Krell factory and ensure all freight (ship­ping) charges are prepaid.

The product may also be hand delivered if arrangements with the
Service Department have been made in advance. Proof of purchase
will be required for warranty validation at the time of hand delivery.

Use the original packaging to ensure the safe transit of the product to
the factory, dealer, or distributor. Krell may, at its discretion, return a
product in new packaging and bill the owner for such packaging if the
product received by Krell was boxed in nonstandard packaging or if
the original packaging was so damaged that it was unusable. If Krell
determines that new packaging is required, the owner will be notified
before the product is returned.

HOW TO RETURN
A PRODUCT

IMPORTANT

To purchase additional packaging, please contact your authorized
Krell dealer, distributor, or the Krell Service Department for assis­tance.

HOW TO PURCHASE
ADDITIONAL PACKING

To contact the Krell Service Department:

TEL [phone]

Monday-Friday, 9:00 am to 5:00 pm EST
FAX [phone]
E-MAIL [e-mail]
WEBSITE http://www.krellonline.com

Your Theater Amplifier Standard product serial number is:

SERIAL NUMBER

HOW TO EXPEDITE
SERVICE

30

Krell Theater Amplifier Standard

Specifications

Theater Amplifier Standard

FREQUENCY 20 Hz to 20 kHz +0 dB, -0.09 dB
RESPONSE 0.25 Hz to 170 kHz +0 dB, -3 dB

SIGNALTO NOISE
RATIO

“A” WEIGHTED >110 dB

TOTAL HARMONIC 1 kHz < 0.03%
DISTORTION (THD) 20 kHz < 0.20%

GAIN 25.8 dB
INPUT IMPEDANCE 100 kOhms
INPUT SENSITIVITY 2.05 Vrms
OUTPUT VOLTAGE Peak to Peak 113 V

RMS 40 V

OUTPUT POWER
EACH CHANNEL 8 Ohms 200 W
4 Ohms 400 W
BRIDGED 8 Ohms 800 W

POWER Standby 60 W
CONSUMPTION Idle 170 W

Max. 2500 W

INPUTS 5 single-ended via RCA connectors

5 balanced via XLR connectors

5 via DB-25 connector

OUTPUTS 5 amplifier channels via five-way binding posts
REMOTE CONNECTORS

12 VDC Out (12 V trigger) via a 3.5 mm connector
12 VDC In (12 V trigger) via a 3.5 mm connector

DIMENSIONS 17.3w x 9.8h x 17.0d in.

43.8w x 24.8h x 43.2d cm

WEIGHT

SHIPPING 110 lb., 50 kg
UNIT ONLY 100 lb., 45.5 kg

All operational features, functions, specifications, and policies
are subject to change without notification.

Krell Industries, Inc.
45 Connair Road
Orange, CT 06477-3650 USA

TEL [phone]
FAX [phone]
E-MAIL [e-mail]
WEBSITE http://www.krellonline.com

Theater Amplifier

Standard

Multichannel Amplifier

v 02.0