Krell Illusion II Preamplifier User Manual

Connecting the
Illusion II
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.

Operating the
Illusion II

Channel Balance
Adjustment

Position the preamplifier where you intend to use it in your system.

1. Neatly arrange and organize wiring to and from the preamplifier and all

components. Separate the AC wires from any audio cables to prevent hum or

other unwanted noise from being introduced into the system.

2. Connect the outputs of your source equipment to the appropriate balanced (11),

or single-ended inputs (12) on the Illusion II.

3. Connect the main outputs (13) on the Illusion II to your amplifier’s inputs.

4. Connect the supplied AC power cord to the IEC power cord receptacle (17)
of the preamplifier.

5. Plug the other end of the AC power cord into AC power and turn on the rear
power switch. The display (3) shows

Illusion II SOFTWARE VERSION, and the stand-

by/power indicator (4) illuminates red, indicating that the Illusion II is in stand-by
mode. When the display shuts off, the Illusion II is ready to be powered on.

Note

Use only the power cord provided with the Illusion II 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 preamplifier to perform optimally.

After the Illusion II is connected to your system and to AC power you may begin
operation:

1. Press the power button (1) on the front panel, or the remote control power key.
The standby/power Indicator turns blue. The display shows the factory default
input:

S-1, and level: 000. The Illusion II is now in the operational mode.

2. With the preamplifier output muted, or the volume fully attenuated, select a

source manually using the front panel input select buttons (5 or 6) or the remote

input select keys. Start playing the source. Use the level buttons (10) or the
remote level keys to set the volume to a comfortable level.

3. To return the preamplifier to the stand-by mode, press the power button (1) or

remote power key. (We recommend leaving the Illusion II in the stand-by mode

when it is not playing music.)

The balance function allows adjustment of the left and right balance. The options
are:

CENTER, L .5-5 dB <, R .5-5 dB >. The remote control has direct keys (D) to make

these adjustments. For front panel adjustment follow the steps listed below.

1. Press the preamplifier menu button (9), then use the level control knob, or the

remote control up and down keys to select:

BALANCE.

2. Press the enter button (8) or remote enter key. The display shows the default
mode:

CENTER.

3. Use the level buttons, or the up and down keys, to select the desired balance

option from 0 to +5 dB in .5 dB increments, left or right.

4. Press the enter button or key to confirm the selection. The display reads:

BALANCE.

5. Press the menu button to exit the menu.

THE LEADER IN AUDIO ENGINEERING

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 Illusion II
in the future, repack the unit in
its original packaging to prevent
shipping damage.

Placement

Illusion II

Stereo Preamplifier

SETUP GUIDE

Thank you for your purchase of the Krell Illusion II Stereo Preamplifier. The Illusion II
features Krell Current Mode circuit topologies, balanced technology, and a robust
power supply for exceptional audio performance. The Illusion II preamplifier includes
a digital input module and a headphone output. A thoughtful suite of menu options
ensures that the Illusion II can be customized for the greatest ease of operation.

The preamplifier’s front panel provides power, input selection, level control, menu

functions, and status display. The rear panel allows connection to audio sources,
power amplifiers, AC power, and other system components.

The remote control provides power, preamplifier, level control, navigation and

customization functions, CD and DVD player controls and menu configuration.

Do not place the preamplifier 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 preamplifier 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 preamplifier 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 Preamplifier chassis
1 IEC connector (AC power) cord
1 Remote control

2. Carefully remove all items from the shipping box.

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

wrapping.

We recommend that you place the preamplifier on a firm, level surface, away from
excessive heat, humidity, or moisture. The preamplifier requires at least two inches

(5 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.

2 AAA remote batteries
1 T-10 Torx wrench for remote
1 Setup Guide

4 Krell Illusion II

MODEL Illusion II Preamplifier

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

SERIAL NUMBER

AC POWER GUIDELINES

The Illusion II preamplifier has superb regulation and does not require a dedicated
AC circuit. Avoid connections through extension cords or multiple AC adapters. High
quality 15 amp AC strips are acceptable. The use of AC line conditioning devices is
not recommended. The features provided by these devices are already on board the

Illusion II.

Krell Illusion II 1

Figure 1 The Illusion II Front Panel

Figure 3 The Illusion II Back Panel

17

Front Panel

1 5 9

1 Power

Use this to switch the
preamplifier between
stand-by and operational
modes.

2 Display

This provides channel

status messages,
in-cluding input selection,

volume level, balance

offset, and menu
selections.

3 Infrared sensor

This receives commands

from the remote control.
Make sure this is not
obstructed.

4 Stand-by/Power

indicator

This power indicator
illuminates red (stand­by) when the Illusion II is
plugged into a standard

86

AC wall receptacle
and rear power switch
is on. The power
indicator illuminates
blue (operational mode)
when the power button
(1) is pressed while the
Illusion II is in stand-by
mode.

5 Analog Input selectors

Use these to select
the corresponding
rear panel input that is
connected to a single­ended (S-1, S-2, S-3),
or balanced (B-1, B-2)
analog source. The
display (2) shows the
selected input and

volume level. Pressing

the input button on the

active source will mute

all outputs. A second
press will unmute the

7

24

outputs.

6 Digital Input selector

Use this to select the

D/A converter module.

Pressing and holding the
digital button will cycle
through the additional
digital inputs.

7 Headphone Jack

1/4" stereo headphone
jack. The main outputs
are muted when
headphones are being
used.

8 Enter button

Use this to configure the
menu functions of the
Illusion II. See menu (9).

9 Menu button

Use this to access the
menu functions of the
Illusion II.

10

10 Level control buttons

Use these buttons to
increase or decrease

system volume level.
The level control buttons

or keys also select menu
options that customize
the Illusion II.

3

Back Panel

11 12 1813 14 16

11 Balanced inputs: B-1

and B-2

These XLR balanced
analog source input
connectors are wired
as follows:

Pin 1 Ground

Pin 2 Non-inverting
Pin 3 Inverting

12 Single-ended inputs:

S-1, S-2, and S-3

There are 3 single­ended analog source
inputs with RCA
connector pairs.

13 Main outputs

The Illusion II is

equipped with one

balanced XLR output
pair and one single­ended RCA output pair.

14 RS-232 port

This port receives

messages from a
computer-based control

system, providing

integrated control of all
preamplifier functions.

15 RC-5 in

This remote connector
is used with third-party
remote control systems

that provide RC-5
(IR) data via a wired

connection. A stereo tip,

ring, sleeve 1/8” mini

connector is used in the
following configuration:
Tip = RC-5 data
Ring = +5 V

Sleeve = GND.

16 12 VDC in/out

(12 V trigger)

There are 2 outputs
and one input that send

and receive 12 VDC

power on/off (trigger)
signals to and from
other Krell components,

and other devices

that incorporate a 12
V trigger. This allows
other components to be
turned on/off, or to/from
stand-by, through the
remote control.

17 IEC power cord

receptacle and power
switch

This is for use with the

provided AC power

cord. Plug the other end
into an AC Mains supply
capable of supplying the

15

correct AC voltage and

current for the power
supply. This connector
and power cord must
remain unobstructed for

easy removal in case of

an emergency.

18 Digital inputs: D-1,

D-2, D-3, D-4, and D-5

There are 2 coaxial

inputs using RCA
connectors, 2 optical
connectors using Toslink
connectors, and 1 AES/
EBU using an XLR
connector.

Remote
Control

Figure 2 The
Illusion II
Remote Control

2 Krell Illusion II Krell Illusion II 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™ are trademarks of Krell Industries,

LLC. All other trademarks and trade names are registered to their respective companies.
© 2014 by Krell Industries, LLC., All rights reserved.

Keys labeled 1 to 10

have the same function

(and callout number) as
the front panel controls.

Keys labeled A through

K are unique to the

re-mote control, and are
described below:

A Phase key

Inverts the polarity

of the audio signal. A
lowercase i is displayed
when the polarity is

inverted.

B Mute key

Use this mute all
outputs. A second press
of the mute key will
unmute the outputs.

C Sel(ect) key

Cycles through the
digital inputs.

D Bal(ance) keys

Use to balance left and

right output levels.

E Transport keys

These keys are
functional with all Krell
CD and DVD players.

F CD key

Press this to make the
transport keys operate
Krell CD players.

G Direction keys

Use these keys to

navigate CD and DVD

menus.

H Select Key

Use this to make
selections from CD and
DVD menus.

I DVD key

Press this to make the
transport keys operate
DVD players.

J Menu key

Use this to enter CD or
DVD player menus.

K Title key

Use this with CD or
DVD player menus.

Note

The remote is shipped

with two AAA batteries
that have to be instal­led. Use the supplied
Torx wrench to remove
the battery panel, then
install the batteries.

Customizing
the
Illusion II

Configurable
Functions

AC Mains
Balance (channel)
Balance (input trim)
Display, Info
Input Level Trim
Input Name, Input Phase
Input Trigger, Mute,
Output Trigger, Recall,

Save, Theater.

The menu button or key
(9) allows you to configure
functions. Enter the menu to

view the list of configurable

functions.

Select a function to view

a submenu of the list of
options that configure the

function. You can configure

some options as well, if a
second submenu appears
when you select an option.

Navigation
Conventions

Navigating the preamplifier

menu is straightforward and
consistent throughout, using
4 functions and the menu
option BACK.

9 Menu Button or Key

To enter the menu,
press the menu button
or key. Once you are in
the menu, you can press
the menu button or key
to exit the menu.

10 Level Control Buttons

or Up and Down Keys

Use the level control

buttons or the up and
down keys on the
re-mote control to scroll
forward and backward
through the menu
hierarchy. Each menu
list is a continuous loop.

8 Enter Button or Key

Press this button or key
to select a function or a
configuration option, and
confirm a selection

3 Front Panel Display

The display shows the

active function and

configurable options.

BACK

Select

BACK to scroll

backwards through
the menu hierarchy, or
to exit a menu option
without confirming that
option.