Krell 7200 Chorus User Manual

AC POWER GUIDELINES

Because of its powerful amplifier channels and high-capacity power supply, iBias
amplifiers will benefit from a dedicated AC circuit. Avoid connections through extension
cords or multiple AC adapters. High quality 20 amp AC strips are acceptable. Please
contact your authorized Krell dealer, distributor befor using any devices designed to alter
or stabilize the AC power.

THE LEADER IN AUDIO ENGINEERING

iBias Power Amplifier

Duo 175 and Duo 300 Stereo Amplifiers

Solo 375 and Solo 575 Mono Amplifiers

Trio 300 Three Channel Amplifier

Chorus 5200 and Chorus 7200 Multi Channel Amplifiers

Connecting the
iBias Amplifier
to Your System

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, keep this gain
value in mind. For the Solo 375
or Solo 575, Krell recommends
the use of CAST. A Krell exclusive
technology, a Krell system
connected with Krell CAST MMF
cable is the fullest expression of
Krell engineering.

Operating the
iBias Amplifier

Follow these steps to connect an iBias amplifier 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 iBias amplifier and all system components.
Separate AC wires from audio cables to prevent hum or other unwanted noises from
being introduced into the system.

3. Connect the left and right loudspeaker cables to the amplifier's left and right
loudspeaker output terminals (14).

4. Connect the left and right outputs of your preamplifier or processor to the appropriate
analog inputs (15, 16, 17) on the iBias amplifier.

5. Plug the AC cord into the IEC connector (22) on the back panel of the iBias amplifier.
Plug the remaining end into the AC wall receptacle. Move the Power Breaker Switch
on the rear panel to the up position. The red stand-by indicator (2) illuminates and the
display shows the model number, firmware version, serial number, and IP address.

Note
Use only the power cord provided with the iBias amplifier to make the connection to AC power.
Operation with a power cord other than the one supplied by Krell can induce noise, limit current, or
otherwise impair the ability of the iBias amplifier to perform optimally.

When powering up any system, alway turn amplifiers on last.
When powering down, always turn amplifiers off first.

1. When the amplifier is in stand-by mode, with the red stand-by indicator (2)
illuminated, turn the amplifier on by pressing the power button on the front panel
(1). There are audible clicks. The blue power indicator (2) illuminates. The display
will show the IP Address and model number and then turn off. The iBias amplifier
is now in the operational mode.

2. With the preamplifier or processor in the mute position, or the volume control fully
attenuated, select a source.

3. Start playing the source.

4. Set the volume to a comfortable listening level using the preamplifier or processor
volume control.

5. To turn the amplifier off, press the power button on the front panel (1). The red
stand-by indicator (2) illuminates.

It is now safe to turn off the rest of the system.

Getting Started

Overview

WARNINGS

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

This CLASS 1 apparatus must
be connected to a MAINS
socket outlet with a protective
earthing connection.

Unpacking

Note
Save all packing materials.
If you need to ship the iBias
amplier in the future, repack
th unit in its original packaging
to prevent shipping damage.

SETUP GUIDE

Krell’s history is rich with breakthrough Class A amplifiers that have helped build
the Krell legacy of offering the best sounding amplifiers available. Audiophiles have
always considered Class A technology to be the best sounding operating state for
amplifiers. However, despite Class A’s unrivaled sound quality, it has fallen out
of fashion because of recent demands to reduce power consumption and heat in
home electronics products. Krell engineering took this challenge and redefined the
meaning of high performance power amplifier. Our goal – unmatched performance,
elegant design, and a compelling array of features. The breakthrough, iBias, a
patent pending circuit delivering Class A operation without the excessive heat
and wasted energy of conventional designs, housed in a striking new form factor,
with network connectivity for advanced access and monitoring. The sound is open
and unconstrained, in a manner that rivals live performance and the true sound of
voices and instruments. Music and dialogue are reproduced with a richness, detail,
and startling dynamics that fill a room.The iBias amplifier is easy to operate and
integrate into your system. The remote control accesses all amplifier functions, and
remote control connection options allow the iBias amplifier to be easily connected
with other components. The Theater Throughput feature provides easy integration of
the amplifier into a home theater system.

Do not place the amplifier where it could be exposed to dripping or splashing.

Do not remove or bypass the ground pin on the end of the AC cord. This may cause radio
frequency interference (RFI) to be introduced into your playback system.

The ventilation slots on the top and bottom of the amplifier as well as the fan openings on the
back must be unobstructed at all times during operation. Do not place flammable material on top
of or beneath the component.

Turn off all systems’ power before connecting the amplifier to any component.

Make sure all cable terminations are of the highest quality, free from frayed ends, short circuits, or
cold solder joints.

THERE ARE NO USER-SERVICEABLE PARTS INSIDE ANY KRELL PRODUCT.

1. Open the shipping box and remove the top layer of foam. You will see these items:

1 iBias amplifier chassis
1 IEC connector (AC power) cord
1 12V Trigger cable

2. Carefully remove all items from the shipping box.

3. Place the amplifier in a safe location and remove the protective plastic wrapping.

4 Krell iBias Amplifier

MODEL: iBias Power Amplifier SERIAL NUMBER:

Krell Industries, LLC., 45 Connair Road, Orange, CT 06477-3650 USA
TEL [phone], FAX [phone], E-MAIL [e-mail]
WEB SITE www.krellonline.com

Placement

Place the iBias amplifier on a firm, level surface, away from excessive heat, humidity,
or moisture. The amplifier requires at least one inch (2.54 cm) of clearance on each
side and at least two inches (5 cm) of clearance above to provide adequate ventilation.
Installations inside cabinetry may need extra ventilation.

Krell iBias Amplifier 1

Figure 1 The iBias Front Panel

1

2 3 4 5

Figure 3 The iBias Back Panel - Solo 575 shown

23

18

24

22

Front Panel

Network
Control

Figure 2
Network Control
Screen -
Duo 300 Shown

1

1 Power Button

Use this button to switch

the iBias amplifier

between stand-by and
operational modes.

After connecting the iBias
amplifier to a network via the
RJ 45 connector (18), enter
the amplifier's IP address into
the address bar of network
device on the same network.

The following additional

features are now available.

2 Power Indicator

The stand-by indicator

illuminates red when
the iBias amplifier
is plugged into a
standard AC wall

receptacle and the rear
panel power breaker
switch is in the up
position, indicating that

the amplifier is in the

stand-by mode and
ready to be switched

to the operational

mode. The indicator
illuminates blue when

the iBias amplifier is in

operational mode.

10

1 Temperature Monitoring

The iBias amplifiers monitor

the temperature of each
channel and adjust fan

speed to maintain proper

cooling. Temperatures listed
in green, yellow, and red,
indicating cool, warm, and
hot operating temperatures.

32

3 Front Panel Display

The front panel display

shows the model

number, firmware
version, serial number,
and IP address. Fault
conditions are also
displayed in the front
panel display.

2 Channel Muting

Press the speaker icon

to mute and unmute an

individual channel

3 Fan Operation Status

9

Fan speed is monitored

8

and is indicated by a
green OK for proper

operation and a red E

6

for an error.

7

4 Display Window

Indicates amplifier stauts
and any fault conditions.

5 Software Update

Press this button to

initiate software update

6 Error Log

Set to Enabled to have
fault conditions sent to

the email addresses

listed in the E-mail
address window (7).

7 E-mail Address window

Up to 3 email addresses

can entered to receive
fault condition emails.

8 Display Timeout

Set the time for how long

the front panel display
remains illuminated. The
Disabled option keeps
the display illuminated
indefintely.

9 No Signal Timer

Set the time for how long
the amplifier remains in
operational mode without

receiving an input signal.
The Disabled option
keeps the amplifier

in operational mode

indefintely.

Note
The network must have
internet access for features
5 and 6 to function.

Back Panel

14 Loudspeaker Outputs

The iBias amplifier is

equipped with standard
binding posts for each
amplifier channel.

15 Balanced Analog Inputs

The iBias amplifiers

are equipped with one
balanced input per channel
via XLR connector.

16 Single-Ended Analog

Inputs

The iBias amplifiers are

equipped with one single­ended input per channel
via RCA connector.

17 CAST Inputs Solo 375

and Solo 575 only

The iBias mono amplifiers

are equipped with one

Figure 4 Connection Diagram

Note

Use only one type of connection: Single-ended, balanced, or CAST between Preamplier and Amplier

14

CAST input via a LEMO
connector and is for use
with a CAST equipped

preamplifier or surround

processor.

18 Ethernet Connection

The RJ45 connector is
used to connect an iBias
amplifier to a network.
Once the amplifier is
connected to a network
router with Internet access,
the amplifier’s advanced
protection systems are
now viewable on an
Internet-connected device.
Excessive current, output
DC, fan speeds, short
circuit, and overheating are
all monitored in real time.
If an issue occurs, the fault

is displayed on the front

panel and reported on

the web server interface.
Emails will automatically
be sent to as many as

three email addresses to

notify Krell, the end user
and/or the dealer of the
condition.

21 12 VDC In (12 V trigger)

The 12 V Trigger input
allows you to place the

iBias amplifier into the

stand-by or operational

mode from other

components.

22 IEC Connector

The connector is for use
with the provided IEC

standard 20 amp power

cord. This connector

2117 15 16

and power cord must
remain unobstructed for
easy removal in case of
emergency.

23 Cooling Fans

iBias amplifiers come
equipped with up to four
fans. Please keep the
fan openings clear of
any obstructions to allow
proper air flow.

24 AC Power Breaker

Switch

Use this switch to change

the iBias amplifier from off

to the stand-by mode.

2 Krell iBias Amplifier Krell iBias Amplifier 3

This product is manufactured in the United States of America. Krell® is a registered trademark of Krell Industries, LLC., and is restricted for
use by Krell Industries, LLC. its subsidiaries, and authorized agents. Krell Current Mode™ and CAST™ is a trademark of Krell Industries, LLC.
All other trademarks and trade names are registered to their respective companies.
© 2014 by Krell Industries, LLC., All rights reserved