Naim Audio SUPERNAIT 2 User Manual

REFERENCE MANUAL

INTEGRATED AMPLIFIERS

SUPERNAIT 2 • NAIT XS 2 • NAIT 5si

ENGLISH

Contents

Section Page

Contents

1 Connections 1

1.1 Interconnect Cables 1

1.2 Loudspeaker Cables 1

2 Mains Power 1

2.1 Mains Plug Wiring 1

2.2 Equipment Fuses 1

2.3 Non-rewirable Mains Plugs 1

2.4 Mains Circuits and Cables 1

3 General Installation 2

3.1 Siting The Equipment 2

3.2 Switching On 2

3.3 Running In 2

3.4 Radio Interference 2

3.5 Lightning Precautions 2

3.6 Problems? 2

3.7 Service and Updates 2

4 SUPERNAIT 2

Introduction, Installation and Connection 3

4.1 Mains Power Connection 3

4.2 Signal Inputs 3

4.3 Speaker Outputs 3

4.4 av and hdd Outputs 3

4.5 Headphone Output 3

4.6 AV Bypass 4

4.7 Other Signal Inputs and Outputs 4

4.8 Power Supply Upgrades 4

4.9 General Connections Notes 4

4.10 External Control and Interface 4

5 Controls and Connections 5

5.1 Front Panel Controls 5

5.2 Rear Panel Connections 5

6 System Connections 6

6.1 SUPERNAIT 2 with Hi-Cap Power Supply 6

6.2 SUPERNAIT 2 with additional

NAP 200 Power Amplifier 6

6.3 SUPERNAIT 2 with Hi-Cap Power Supply

and NAP 200 Power Amplifier 7

7 Amplifier Operation

and Programmable Functions 8

7.1 Automatic Input Switching 8

7.2 Handset Volume and Balance Control 8

7.3 Mute 8

7.4 Display 8

7.5 Switch-on 8

7.6 Remote Control 8

7.7 Defaults 8

7.8 Fault Conditions 8

8 Specifications 9

9 NAIT XS 2

Introduction, Installation and Connection 10

9.1 Mains Power Connection 10

9.2 Signal Inputs 10

9.3 Speaker Outputs 10

9.4 av and hdd Outputs 10

9.5 Headphone Output 10

9.6 AV Bypass 11

9.7 Other Signal Inputs and Outputs 11

9.8 Power Supply Upgrades 11

9.9 General Connections Notes 11

9.10 External Control and Interface 11

10 Controls and Connections 12

10.1 Front Panel Controls 12

10.2 Rear Panel Connections 12

11 System Connections 13

11.1 Nait XS 2 with FlatCap XS Power Supply 13

11.2 Nait XS 2 with Hi-Cap Power Supply

and NAP 200 Power Amplifier 13

12 Amplifier Operation

and Programmable Functions 14

12.1 Automatic Input Switching 14

12.2 Handset Volume Control 14

12.3 Mute 14

12.4 Display 14

12.5 Switch-on 14

12.6 Remote Control 14

12.7 Defaults 14

12.8 Fault Conditions 14

13 Specifications 15

14 NAIT 5si

Introduction, Installation and Connection 16

14.1 Mains Power Connection 16

14.2 Signal Inputs 16

14.3 Speaker Outputs 16

14.4 hdd Output 16

14.5 Headphone Output 16

15 Controls and Connections 17

15.1 Front Panel Controls 17

15.2 Rear Panel Connections 17

16 Amplifier Operation

and Programmable Functions 18

16.1 Automatic Input Switching 18

16.2 AV Bypass 18

16.3 Handset Volume Control 18

16.4 Mute 18

16.5 Display 18

16.6 Remote Control 18

16.7 Defaults 18

16.8 Fault Conditions 18

17 Specifications 19

18 NARCOM 4 Remote Handset 20

18.1 Using NARCOM 4 20

18.2 NARCOM 4 Keys 20

19 Declaration of Conformity 21

20 Statutory Safety Warnings 21

Introduction

Naim Audio products are conceived with performance as the top priority. Careful
installation will help ensure that their full potential is achieved. This manual covers all
integrated amplifiers. It begins with some general installation notes. Product specific
information begins in Section 4.

Note: Please read the
Statutory Safety Warnings
found at the end of this
manual.

1 Connections

It is important for both safety and performance that

the standard cables supplied are not modified.

1.1 Interconnect Cables

If options are available with your equipment and

installation, DIN interconnect sockets should be used in

preference to RCA Phono sockets. One end of each Naim

interconnect cable is marked with a band to establish

its correct orientation. The band denotes the end that

connects to the signal source. Naim Hi-Line interconnect

cable will provide the best results.

Interconnect plugs and sockets should be kept clean

and free from corrosion. The easiest way to clean them

is to switch off the equipment, pull the plugs out of their

sockets, and push them back in again. Contact cleaners

and “enhancers” should not be used as the film they

deposit may degrade the sound.

1.2 Loudspeaker Cables

Loudspeaker cables are vitally important. They should

each be at least 3.5 metres long and of equal length. The

recommended maximum is normally 20 metres although

longer cables may be viable with some Naim amplifiers.

Some Naim amplifiers are designed only to work with

Naim loudspeaker cable and using alternatives may

degrade the performance or even damage the amplifier.

Other Naim amplifiers can be used with any high quality

loudspeaker cable although we recommend that Naim

loudspeaker cable is used. Naim loudspeaker cable is

directional and should be oriented so that the printed

arrow points towards the speakers. The Naim loudspeaker

connectors supplied are designed to comply with

European safety legislation and must be used.

Contact your local retailer or distributor for further advice

on loudspeaker cables and connectors.

2 Mains Power

Where fused plugs are used 13 amp fuses should be

fitted. Fuses of a lower rating will fail after a period

of use. Do not wire voltage dependent resistors or

noise suppressors into mains plugs. They degrade the

mains supply and the sound.

2.1 Mains Plug Wiring

In some territories a mains plug may need to be fitted to

the supplied mains lead. As the colours of the wires in the

mains lead may not correspond with the coloured markings

identifying the terminals in the plug proceed as follows:

The wire coloured GREEN-AND-YELLOW must be

connected to the terminal in the plug marked by the

letter E or by the safety earth symbol or coloured GREEN or

GREEN and YELLOW.

The wire coloured BLUE must be connected to the terminal

in the plug marked with the letter N or coloured BLACK.

The wire coloured BROWN must be connected to the

terminal in the plug marked with the letter L or coloured

RED.

2.2 Equipment Fuses

Mains powered Naim Audio equipment is fitted with a

mains fuse on the rear panel adjacent to the mains input

socket. Replace it if necessary only with the spare fuse

supplied or with an identical fuse. Repeated failure of the

fuse points to a fault that should be investigated by your

retailer or Naim itself.

2.3 Non-rewirable Mains Plugs

If a non-rewirable plug is cut from a mains lead (for

whatever purpose) the plug MUST be disposed of in a way

to render it totally useless. Considerable shock hazard exists

if the cut-off plug is inserted into a mains outlet.

2.4 Mains Circuits and Cables

A hi-fi system usually shares a mains circuit with other

household equipment some of which can cause distortion

of the mains waveform. This distortion can in turn lead to

mechanical hum from mains transformers. Some Naim

transformers are large in size, making them relatively

sensitive to such distortion, and it may be necessary to take

account of transformer hum when siting your equipment.

Transformer hum is not transmitted through the speakers

and has no effect on the performance of the system;

however, a separate mains circuit may reduce it. Such

a circuit (ideally with a 30 or 45 Amp rating) will also

generally improve system performance. Advice on the

installation of a separate mains circuit should be sought

from a qualified electrician.

Use only the mains leads and plugs supplied or the Naim

PowerLine mains cable.

E1

Introduction

3 General Installation

Naim equipment is designed to offer the finest

performance possible avoiding compromise

wherever practical. This can lead to circumstances

that may be unfamiliar. The notes that follow contain

advice specifically related to Naim equipment as

well as more general warnings about the use of

domestic audio products. Please read them carefully.

3.1 Siting The Equipment

In order to reduce the risk of hum audible from the

loudspeakers, power supplies and power amplifiers

should be located a reasonable distance away from

other equipment. The maximum separation distance for

connected equipment is that allowed by the standard

interconnect lead.

Some Naim equipment is extremely heavy. Check the

weight of the equipment prior to lifting and if necessary

use more than one person so that it can be moved safely.

Ensure that your equipment rack or table can easily

support the weight and is stable.

3.2 Switching On

Source components and power supplies should be

switched on before the power amplifiers. Always switch

amplifiers off and wait a minute before connecting or

disconnecting any leads. Always use the power switch on

the product rather than a mains outlet switch.

A “thump” may be heard from the loudspeakers as power

amplifiers are switched on. This is normal, will not cause

any loudspeaker damage and does not point to any fault

or problem. A mild “pop” may also be heard shortly after

equipment is switched off.

3.4 Radio Interference

In some circumstances, depending on where you live

and the earthing arrangements in your home, you may

experience radio frequency interference. Controls on

broadcasting in some territories allow very high levels of

radio frequency radiation and both the choice and exact

siting of equipment may be critical. Susceptibility to radio

frequency interference is related to the wide internal

bandwidth necessary for high sound quality. A radio

frequency filter kit is available for some Naim equipment

but sound quality will be progressively compromised as

more elements of the kit are fitted.

3.5 Lightning Precautions

Your Naim hi-fi system can be damaged by lightning

and should be turned off and disconnected from the

mains when there is risk of lightning strike. For complete

protection all mains plugs and any aerial cables should be

disconnected when not in use.

3.6 Problems?

Consumer protection varies from country to country. In

most territories a retailer must be prepared to take back

any equipment he has sold if it cannot be made to work

satisfactorily. A problem may be due to a fault in the

system or its installation so it is essential to make full use of

your dealer’s diagnostic skills. Please contact your local

distributor, or Naim Audio directly, if any difficulties cannot

be resolved.

Some Naim equipment is made in special versions for

different territories and this makes it impracticable to

arrange international guarantees. Please establish the

local guarantee arrangements with your retailer. Contact

Naim Audio directly for help and advice if necessary.

3.3 Running In

Naim equipment takes a considerable time to run in

before it performs at its best. The duration varies, but under

some conditions the sound may continue to improve for

over a month. Better and more consistent performance

will be achieved if the system is left switched on for long

periods. It is worth remembering however that equipment

left connected to the mains can be damaged by

lightning.

3.7 Service and Updates

It is essential that repairs and updates are only carried

out by an authorised Naim retailer or at the factory by

Naim itself. Many components are custom made, tested

or matched and appropriate replacements are often

unobtainable from other sources.

Direct contact to Naim for service or update information

should be made initially through Customer Services:

Tel: [phone]
Email: [e-mail]

Please quote the product serial number (found on its rear

panel) in all correspondence.

E2

SUPERNAIT 2

4 SUPERNAIT 2 Introduction, Installation and Connection

The Supernait 2 is a very high performance stereo integrated amplifier that combines a
preamplifier providing six line-level analogue inputs with a power amplifier rated at 80
Watts per channel. The Supernait 2 can be controlled by either its remote handset or by
front panel mounted volume and balance knobs, and mute and input selection buttons.
The Supernait 2 remote handset is described in Section 18 of this manual. A front panel

6.3mm jack socket enables the use of headphones with the Supernait 2.

A variety of power supply upgrade, alternative preamplifier and alternative or additional
power amplifier options are possible for the Supernait 2. Diagrams illustrating the
connection of some of these are shown in Section 6. If no power supply or alternative
amplifier options are to be employed, the Supernait 2 preamp/power amp link plug,
supplied in the accessory pack, must be fitted to the rear panel “preamp out” and
“power amp in” sockets. The link plug is shown fitted in Diagram 5.2.

Your Supernait 2 should be installed on a dedicated equipment stand intended for
the purpose. Do not stand it directly on top of another item of equipment. Care should
be taken to ensure that it is level. The amplifier should be installed in its final location
before connecting cables or switching on. Ensure that the volume is turned down before
switching on.

4.1 Mains Power Connection

Connect the Supernait 2 to a mains power socket using

either the mains cable supplied or a Naim Power-Line.

Note: The Supernait 2
incorporates an AV
Bypass switch on its rear
panel. The switch should
only be set to “On” if the
amplifier is to be used
in conjunction with an
AV processor in a home
theatre system. In all
other installations the
AV Bypass switch should
be set to “Off”. Speaker
and amplifier damage
may occur if a signal is
inadvertently connected
to the Supernait 2 av
input while the AV
Bypass switch is “On”.

4.2 Signal Inputs

The Supernait 2 front panel input buttons select the source

input signal to be routed to the integral power amplifier

and the loudspeakers or headphones. The six buttons are
labelled cd, tuner, hdd (hard disk drive), av, aux 1 and aux 2.

The cd, tuner, hdd and av input buttons correspond to

parallel DIN and RCA phono input sockets on the rear
panel, while the aux 1 input button corresponds only to a

pair of RCA phono sockets.

Note: The hdd and av sockets carry both inputs and

outputs. See Section 4.4 for more information.

The aux 2 input button corresponds to a DIN input socket
on the rear panel. The aux 2 DIN socket also carries a
power supply output intended to power a Naim Stageline
or SuperLine phono preamplifier.

Note: For optimum sound quality DIN sockets should be

used in preference to RCA phono sockets.

Note: Where an input has DIN and phono socket options

only one should be connected at any one time.

Always use high quality interconnect cables to connect

sources to inputs. The Naim Hi-Line will produce the best

results.

4.3 Speaker Outputs

A set of stereo speaker connection sockets is provided on

the rear panel. Custom Naim loudspeaker connectors are

supplied to make the connection and in order to comply

with current European safety regulations these should

always be used. Naim speaker cable will provide the best

results, however, a wide range of speaker cable types can

be used without risk of damage to the amplifier.

Ensure when connecting speakers that they are “in

phase”. That is, the positive and negative connection

orientation at both the speaker and amplifier ends of the

cable is the same for both channels.

4.4 av and hdd Outputs

The Supernait 2 av and hdd inputs have associated

outputs that enable the selected input signal to be routed

externally; to an audio recording component for example.

Note: The av and hdd outputs remain active while

their corresponding inputs are selected. Take care that

a feedback loop is not inadvertently created by the

simultaneous selection of input and output.

4.5 Headphone Output

The Supernait 2 headphone output is able to drive the

majority of headphone types. The 6.3mm (1/4”) jack

socket, rather than the smaller 3.5mm jack socket, provides

more reliable connection and potentially higher sound

quality. Most high-quality headphones are supplied with

an adaptor that enables use with either 3.5mm or 6.3mm

jack sockets. Inserting a headphone plug will mute the

Supernait 2 speaker outputs. Removing the headphone

plug will restore the outputs.

E3

SUPERNAIT 2

4.6 AV Bypass

The Supernait 2 can be integrated within a multi-channel

home theatre system, driving the front left and right

channel speakers, by engaging its AV Bypass mode.

AV Bypass mode enables a home theatre processor to

take over volume control of signals connected to the
Supernait 2 av input. It is engaged using the switch on the

rear panel. The Supernait 2 volume control indicator will

extinguish when AV Bypass mode is engaged and the av

input is selected. The remote handset volume control will

also be disabled.

Note: The AV Bypass feature must be used with care. It

bypasses the Supernait 2 volume control leaving any signal

connected to the av input to be passed to the speakers at

full volume.

Note: Inserting a headphone plug while AV Bypass mode

is selected temporarily returns the Supernait 2 to normal

operation. Removing the headphone plug will return the

Supernait 2 to AV Bypass mode.

Note: The mute function is disabled when AV Bypass mode

is engaged.

4.7 Other Signal Inputs and Outputs

The Supernait 2 incorporates DIN bi-amp (output), RCA
phono sub out, DIN pre-amp out, and DIN power-amp in
sockets on its rear panel. In normal use the pre-amp out
and power-amp in sockets are connected by a link plug.

The link plug should be removed only in the following

circumstances:

Diagrams 6.1, 6.2 and 6.3 illustrate some applications of

the Supernait 2 preamp out, power amp in and bi-amp

sockets.

4.8 Power Supply Upgrades

The Supernait 2 preamplifier can be upgraded through the

connection of an external Flatcap, Hi-Cap or Supercap

power supply. Diagrams illustrating power supply upgrades

are shown in Section 6. The Supernait 2 and external power

supply must be switched off when connections are made.

Switch on the external power supply first followed by the

Supernait 2 when all connections are complete.

4.9 General Connections Notes

The Supernait 2 negative input and output connections

for each channel are common. The mains earth (ground)

should always be connected regardless of what other

equipment is used in conjunction with the amplifier. The

mains earth only grounds the case and the electrostatic

screen within the transformer, and is not connected to the

signal negative. In order to avoid hum loops, the signal

negative of the whole system should be connected to the

mains earth (ground) in one place.

A signal ground connection is fitted to the Supernait 2 rear

panel. This is intended to be used to connect a turntable

pick-up arm signal earth only.

4.10 External Control and Interface

The Supernait 2 is fitted on its rear panel with a 3.5mm jack

Remote In socket and a mini-USB interface socket.

• A power supply upgrade is to be used.

• An alternative preamplifier is to be used with the

Supernait 2 power amplifier.

• An alternative power amplifier is to be used with the

Supernait 2 preamplifier.

Note: When an external preamplifier is connected to the

Supernait 2 power-amp in socket, a fault will initially be

indicated by the Supernait 2 mute button flashing. To clear

the fault, press and hold the flashing mute button. This will

un-mute the amplifier and turn off the display and volume

indicator.

Note: The power amp in socket carries a 24V DC power

supply output intended for Naim preamplifiers that require

an external power supply.

The Supernait 2 DIN bi-amp output socket provides a

preamp output signal that enables a second power

amplifier to be used in conjunction with the Supernait 2

power amplifier.

The RCA phono sub out sockets provide a stereo output

intended for connection to an active subwoofer. The

output signal is a duplicate of the preamplifier output. No

low-pass filtering is applied.

The Remote In socket can be used for RC5 remote control

of the Supernait 2 via a wired connection or a remote IR

repeater.

The mini-USB socket enables firmware upgrades and

diagnostic tests to be carried out. Contact your Naim

retailer for more information if required.

Note: The mini-USB interface is not intended for the

connection of USB memory devices.

E4

SUPERNAIT 2

5 Controls and Connections

5.1 Front Panel Controls

source selection

volume

balance

5.2 Rear Panel Connections

power

mains

input

and fuse

cd and tuner

Inputs

ch1
ch2

-ve

nc
nc

left

speaker

USB

update

interface

av and hdd

Inputs

ch1
ch2

-ve

right

speaker

av
bypass
switch

ch1
(out)

ch2
(out)

remote in

aux 2 input

+ve
ch2

-ve

+ve

ch1

headphone

mute

socket

aux 2

bi-amp out

signal ground

preamp out and

sub
out

in &
power
out

aux 1
in RCA

av in
& out

av in
RCA

hdd in
& out

hdd
in RCA

tuner
in

tuner
in RCA

power amp in. Link

plug tted.

Note: The link plug should be removed only if a power

supply upgrade is to be used or an alternative preamplifier

is to use the Supernait 2 power amplifier section. It should

remain fitted in all other circumstances.

cd in

cd
in RCA

preamp and

bi-amp out

ch2 ch2

-ve -ve

ch1 ch1

nc +ve

power amp in

E5

SUPERNAIT 2

6 System Connections

The following three diagrams illustrate examples of Supernait 2 system connections. Many
other systems using external power supplies or additional power amplifiers are possible.
Contact your Naim retailer or local distributor for more information.

6.1 SUPERNAIT 2 with Hi-Cap Power Supply

power

mains

input

and fuse

mains input
and fuse

Note: The Supernait 2 should remain connected to mains

power at all times.

cable
direction
marker

6.2 SUPERNAIT 2 with additional NAP 200 Power Amplifier

Interconnect Cables

4 to 4 pin DIN

240° 5 to 5 pin DIN

power

mains

input

and fuse

mains input
and fuse

Note: The Supernait 2 should remain connected

to mains power at all times.

E6

SUPERNAIT 2

6.3 SUPERNAIT 2 with Hi-Cap Power Supply and NAP 200 Power Amplifier

power

mains

input

and fuse

mains input
and fuse

mains input
and fuse

Note: The Supernait 2 should remain connected to mains

power at all times.

cable
direction
marker

Interconnect Cables

4 to 4 pin DIN

240° 5 to 5 pin DIN

E7

SUPERNAIT 2

7 Amplifier Operation and Programmable Functions

The Supernait 2 incorporates some programmable functions and operational nuances.
These are described in the following paragraphs.

7.1 Automatic Input Switching

With Automatic Input Switching engaged the appropriate

source input will be selected as soon as any handset

function for that (Naim) source component is operated.

For example, if the tuner input is selected and the cd

play key is pressed on the handset, the Supernait 2 will

automatically switch to the cd input. Automatic Input

Switching can be programmed to operate on any
combination of the cd, tuner, hdd and av input buttons.

To enable Automatic Input Switching, first switch the

Supernait 2 into program mode by pressing and holding
the handset prog key (with the handset in preamplifier
mode). The front panel mute button will illuminate if

automatic switching is already enabled. If it is not enabled
it can be switched on by pressing the mute button.

With automatic switching enabled, pressing the mute

button again will reveal the inputs selected for auto

switching by their indicators illuminating for a short time.
Repeated operation of the mute button will sequentially
select through each possible combination of cd, tuner,

hdd and av inputs and auto switching disabled (all

indicators off). When the desired inputs selected for auto

switching are indicated, stop pressing the button.

Automatic Input Switching only becomes operational

on exit from program mode by pressing and holding the
handset prog key.

Note: The Supernait 2 will leave program mode

automatically if no control commands are received for five

minutes.

Note: In a few cases some further equipment configuration

may be required for auto switching to operate correctly.

Please contact your retailer or local distributor for advice.

7.2 Handset Volume and Balance Control

The remote handset volume and balance keys provide

some alternative control characteristics. A short press and

release of a key will adjust by a preset “nudge”, while

pressing and holding the key will result in three seconds of

slow adjustment followed by continual fast adjustment.

7.3 Mute

Mute silences the outputs and can be selected or
deselected by pressing the front panel mute button or
remote handset mute key.

7.4 Display

The Supernait 2 front panel button illumination can

be switched off by pressing the remote handset (in
preamplifier mode) disp function. Any subsequent handset

or front panel operation will temporarily restore the display.
A second operation of the disp function will restore the

display.

7.5 Switch-on

After switch-on the Supernait 2 will remain muted for 30

seconds while control systems and circuits stabilise.

7.6 Remote Control

The Narcom 4 remote handset supplied with the

Supernait 2 duplicates all configuration and control

functions. See Section 18 for more information.

7.7 Defaults

To restore all Supernait 2 programmable settings to the
factory defaults press and hold the remote handset disp

key while the unit is in program mode. The Supernait 2 will

exit from program mode following this operation.

7.8 Fault Conditions

The Supernait 2 will indicate fault conditions by flashing

front panel button buttons. The following table lists the fault

indications.

Fault Flashing Button

Link Plug or Power Supply mute

Excess Temperature cd

Excess Current tuner

E8

SUPERNAIT 2

8 Specifications

Power Output: 80W + 80W RMS into 8ohms (135W + 135W into 4ohms)
Inputs: 6 analogue line level suitable for 2V sources (0.5V to 7.0V)
Headphones: Front panel 6.3mm (1/4”) jack socket suitable for 16Ω to 1kΩ

headphones

Auxiliary Power Output: +24V on ‘aux 2 in & pwr’ for Naim phono stages
Fixed Line Level Outputs: ‘av out’ and ‘hdd out’
Variable Line Level Outputs: ‘sub out’, ‘bi-amp out’ and ‘pre-amp out’
Quiescent Consumption: 37VA
Dimensions (H x W x D): 87 x 432 x 314mm
Weight: 13.9kg
Mains Supply: 100V, 115V or 230V, 50/60Hz

For full technical specifications please visit our website:

http://www.naimaudio.com/hifi-products/supernait-2

E9

NAIT XS 2

9 NAIT XS 2 Introduction, Installation and Connection

The Nait XS 2 is a very high performance stereo integrated amplifier that combines a
preamplifier providing six line-level analogue inputs with a power amplifier rated at 70
Watts per channel. The Nait XS 2 can be controlled by either its remote handset or by a
front panel mounted volume knob and mute and input selection buttons. The Nait XS 2
remote handset is described in Section 18 of this manual. A front panel 6.3mm jack socket
enables the use of headphones with the Nait XS 2.

A variety of power supply upgrade, alternative preamplifier and alternative or additional
power amplifier options are possible for the Nait XS 2. Diagrams illustrating the connection
of some of these are shown in Section 11. If no power supply or alternative amplifier
options are to be employed, the Nait XS 2 preamp/power amp link plug, supplied in
the accessory pack, must be fitted to the rear panel “preamp out” and “power amp in”
sockets. The link plug is shown fitted in Diagram 10.2.

Your Nait XS 2 should be installed on a dedicated equipment stand intended for the
purpose. Do not stand it directly on top of another item of equipment. Care should
be taken to ensure that it is level. The amplifier should be installed in its final location
before connecting cables or switching on. Ensure that the volume is turned down before
switching on.

9.1 Mains Power Connection

Connect the Nait XS 2 to a mains power socket using

either the mains cable supplied or a Naim Power-Line.

Note: The Nait XS 2
incorporates an AV
Bypass switch on its rear
panel. The switch should
only be set to “On” if the
amplifier is to be used
in conjunction with an
AV processor in a home
theatre system. In all
other installations the
AV Bypass switch should
be set to “Off”. Speaker
and amplifier damage
may occur if a signal is
inadvertently connected
to the Nait XS 2 av input
while the AV Bypass
switch is “On”.

9.2 Signal Inputs

The Nait XS 2 front panel input buttons select the source

input signal to be routed to the integral power amplifier

and the loudspeakers or headphones. The six buttons are
labelled cd, tuner, hdd (hard disk drive), av, aux 1 and aux 2.

The cd, tuner, hdd and av input buttons correspond to

parallel DIN and RCA phono input sockets on the rear
panel, while the aux 1 input button corresponds only to a

pair of RCA phono sockets.

Note: The hdd and av sockets carry both inputs and

outputs. See Section 9.4 for more information.

The aux 2 input button corresponds to a DIN input socket
on the rear panel. The aux 2 DIN socket also carries a
power supply output intended to power a Naim Stageline
or SuperLine phono preamplifier.

Note: For optimum sound quality DIN sockets should always

be used in preference to RCA phono sockets.

Note: Where an input has DIN and phono socket options

only one should be connected at any one time.

Always use high quality interconnect cables to connect

sources to inputs. The Naim Hi-Line will produce the best

results.

9.3 Speaker Outputs

A set of stereo speaker connection sockets is provided on

the rear panel. Custom Naim loudspeaker connectors are

supplied to make the connection and in order to comply

with current European safety regulations these should

always be used. Naim speaker cable will provide the best

results, however, a wide range of speaker cable types can

be used without risk of damage to the amplifier.

Ensure when connecting speakers that they are “in

phase”. That is, the positive and negative connection

orientation at both the speaker and amplifier ends of the

cable is the same for both channels.

9.4 av and hdd Outputs

The Nait XS 2 av and hdd inputs have associated outputs

that enable the selected input signal to be routed

externally; to an audio recording component for example.

Note: The av and hdd outputs remain active while

their corresponding inputs are selected. Take care that

a feedback loop is not inadvertently created by the

simultaneous selection of input and output.

9.5 Headphone Output

The Nait XS 2 headphone output is able to drive the

majority of headphone types. The 6.3mm (1/4”) jack

socket, rather than the smaller 3.5mm jack socket, provides

more reliable connection and potentially higher sound

quality. Most high-quality headphones are supplied with an

adaptor that enables use with either 3.5mm or 6.3mm jack

sockets. Inserting a headphone plug will mute the

Nait XS 2 speaker outputs. Removing the headphone plug

will restore the outputs.

E10

NAIT XS 2

9.6 AV Bypass

The Nait XS 2 can be integrated within a multi-channel

home theatre system, driving the front left and right

channel speakers, by engaging its AV Bypass mode.

AV Bypass mode enables a home theatre processor to

take over volume control of signals connected to the Nait
XS 2 av input. It is engaged using the switch on the rear

panel. The Nait XS 2 volume control indicator will extinguish

when AV Bypass mode is engaged and the av input is

selected. The remote handset volume control will also be

disabled.

Note: The AV Bypass feature must be used with care. It

bypasses the Nait XS 2 volume control leaving any signal

connected to the av input to be passed to the speakers at

full volume.

Note: Inserting a headphone plug while AV Bypass mode

is selected temporarily returns the Nait XS 2 to normal

operation. Removing the headphone plug will return the

Nait XS 2 to AV Bypass mode.

Note: The mute function is disabled when AV Bypass mode

is engaged.

9.7 Other Signal Inputs and Outputs

The Nait XS 2 incorporates RCA phono sub out, DIN pre-

amp out, and DIN power-amp in sockets on its rear panel.

In normal use the pre-amp out and power-amp in sockets

are connected by a link plug. The link plug should be

removed only in the following circumstances:

• A power supply upgrade is to be used.

• An alternative preamplifier is to be used with the

Nait XS 2 power amplifier.

• An alternative power amplifier is to be used with the Nait

XS 2 preamplifier.

Note: When an external preamplifier is connected to

the Nait XS 2 power-amp in socket, a fault will initially be

indicated by the Nait XS 2 mute button flashing. To clear

the fault, press and hold the flashing mute button. This will

un-mute the amplifier and turn off the display and volume

indicator.

9.8 Power Supply Upgrades

The Nait XS 2 preamplifier can be upgraded through the

connection of an external Flatcap, Hi-Cap or Supercap

power supply. Diagrams illustrating power supply upgrades

are shown in Section 11. The Nait XS 2 and external power

supply must be switched off when connections are made.

Switch on the external power supply first followed by the

Nait XS 2 when all connections are complete.

9.9 General Connections Notes

The Nait XS 2 negative input and output connections for

each channel are common. The mains earth (ground)

should always be connected regardless of what other

equipment is used in conjunction with the amplifier. The

mains earth only grounds the case and the electrostatic

screen within the transformer, and is not connected to the

signal negative. In order to avoid hum loops, the signal

negative of the whole system should be connected to the

mains earth (ground) in one place.

A signal ground connection is fitted to the Nait XS 2 rear

panel. This is intended to be used to connect a turntable

pick-up arm signal earth only.

9.10 External Control and Interface

The Nait XS 2 is fitted on its rear panel with a 3.5mm jack

Remote In socket and a mini-USB interface socket.

The Remote In socket can be used for RC5 remote control

of the Nait XS 2 via a wired connection or a remote IR

repeater.

The mini-USB socket enables firmware upgrades and

diagnostic tests to be carried out. Contact your Naim

retailer for more information if required.

Note: The mini-USB interface is not intended for the

connection of USB memory devices.

Note: The power amp in socket carries a 24V DC power

supply output intended for Naim preamplifiers that require

an external power supply.

The RCA phono sub out sockets provide a stereo output

intended for connection to an active subwoofer. The

output signal is a duplicate of the preamplifier output. No

low-pass filtering is applied.

Diagrams 11.1 and 11.2 illustrate some applications of the

Nait XS 2 preamp out and power amp in sockets.

E11

NAIT XS 2

10 Controls and Connections

10.1 Front Panel Controls

source selection

volume

10.2 Rear Panel Connections

power

mains

input

and fuse

cd and tuner

Inputs

ch1
ch2

-ve

nc
nc

preamp out power amp in

ch2 ch2

-ve -ve

ch1 ch1

nc +ve

left

speaker

av and hdd

Inputs

ch1
ch2

-ve

right

speaker

ch1
(out)

ch2
(out)

USB
update
interface

aux 2 input

+ve

ch2

-ve

signal

ground

+ve

ch1

headphone socket

out

aux 1 in

RCA

subwoofer

mute

av in
RCA

hdd in

RCA

tuner in

RCA

remote in

aux 2

av in

hdd

AV

bypass

switch

preamp out

and power

amp in. Link

plug tted.

in &
power
out

& out

tuner incd in
in &
out

Note: The link plug should be removed only if a power

supply upgrade is to be used, an alternative preamplifier

is to use the Nait XS 2 power amplifier section, or an

alternative power amplifier is to use the Nait XS 2

preamplifier section. It should remain fitted in all other

circumstances.

Note: The Nait XS 2 features various technologies to reduce

microphonic effects. Some movement of the board and

sockets when connecting and disconnecting cables is

normal.

cd in

RCA

E12

NAIT XS 2

11 System Connections

The following two diagrams illustrate examples of Nait XS 2 system connections. Many
other systems using external power supplies or additional power amplifiers are possible.
Contact your Naim retailer or local distributor for more information.

11.1 Nait XS 2 with FlatCap XS Power Supply

power

power

mains input
and fuse

mains input and fuse

Note: The Nait XS 2 should remain

connected to mains power at all times.

11.2 Nait XS 2 with Hi-Cap Power Supply and NAP 200 Power Amplifier

power

mains input
and fuse

Note: The Nait XS 2 should remain connected to

mains power at all times.

mains input and fuse

mains input and fuse

E13

cable
direction
marker

Interconnect Cables

4 to 4 pin DIN

240° 5 to 5 pin DIN

NAIT XS 2

12 Amplifier Operation and Programmable Functions

The Nait XS 2 incorporates some programmable functions and operational nuances. These
are described in the following paragraphs.

12.1 Automatic Input Switching

With Automatic Input Switching engaged the appropriate

source input will be selected as soon as any handset

function for that (Naim) source component is operated. For

example, if the tuner input is selected and the cd play key

is pressed on the handset, the Nait XS 2 will automatically

switch to the cd input. Automatic Input Switching can be
programmed to operate on any combination of the cd,

tuner, hdd and av input buttons.

To enable Automatic Input Switching, first switch the Nait XS

2 into program mode by pressing and holding the handset

prog key (with the handset in preamplifier mode). The front

panel mute button will illuminate if automatic switching is

already enabled. If it is not enabled it can be switched on
by pressing the mute button.

With automatic switching enabled, pressing the mute

button again will reveal the inputs selected for auto

switching by their indicators illuminating for a short time.
Repeated operation of the mute button will sequentially
select through each possible combination of cd, tuner,

hdd and av inputs and auto switching disabled (all

indicators off). When the desired inputs selected for auto

switching are indicated, stop pressing the button.

Automatic Input Switching only becomes operational

on exit from program mode by pressing and holding the
handset prog key.

Note: The Nait XS 2 will leave program mode automatically

if no control commands are received for five minutes.

Note: In a few cases some further equipment configuration

may be required for auto switching to operate correctly.

Please contact your retailer or local distributor for advice.

12.2 Handset Volume Control

The remote handset volume keys provide some alternative

control characteristics. A short press and release of a key

will adjust by a preset “nudge”, while pressing and holding

the key will result in three seconds of slow adjustment

followed by continual fast adjustment.

12.3 Mute

Mute silences the outputs and can be selected or
deselected by pressing the front panel mute button or
remote handset mute key.

12.4 Display

The Nait XS 2 front panel button illumination can

be switched off by pressing the remote handset (in
preamplifier mode) disp function. Any subsequent handset

or front panel operation will temporarily restore the display.
A second operation of the disp function will restore the

display.

12.5 Switch-on

After switch-on the Nait XS 2 will remain muted for 30

seconds while control systems and circuits stabilise.

12.6 Remote Control

The Narcom 4 remote handset supplied with the

Nait XS 2 duplicates all configuration and control functions.

See Section 18 for more information.

12.7 Defaults

To restore all Nait XS 2 programmable settings to the
factory defaults press and hold the remote handset disp

key while the unit is in program mode. The Nait XS 2 will exit

from program mode following this operation.

12.8 Fault Conditions

The Nait XS 2 will indicate fault conditions by flashing front

panel button buttons. The following table lists the fault

indications.

Fault Flashing Button

Link Plug or Power Supply mute

Excess Temperature cd

Excess Current tuner

Note: The Nait XS 2 does not incorporate any facility for

channel balance adjustment.

E14

NAIT XS 2

13 Specifications

Power Output: 70W + 70W RMS into 8ohms (100W + 100W into 4ohms)
Inputs: 6 analogue line level suitable for 2V sources (0.5V to 7.0V)
Headphones: Front panel 6.3mm (1/4”) jack socket suitable for 16Ω to 1kΩ

headphones

Auxiliary Power Output: +24V on ‘aux 2 in & pwr’ for Naim phono stages
Fixed Line Level Outputs: ‘av out’ and ‘hdd out’
Variable Line Level Outputs: ‘sub out’ and ‘pre-amp out’
Quiescent Consumption: 16VA
Dimensions (H x W x D): 70 x 432 x 301mm
Weight: 8.4kg
Mains Supply: 100V, 115V or 230V, 50/60Hz

For full technical specifications please visit our website:

http://www.naimaudio.com/hifi-products/nait-xs-2

E15

NAIT 5si

14 NAIT 5si Introduction, Installation and Connection

The Nait 5si is a very high performance stereo integrated amplifier that combines a
preamplifier providing four line-level analogue inputs with a power amplifier rated at
60 Watts per channel. The Nait 5si can be controlled by either its remote handset or by
a front panel mounted volume knob and input selection buttons. The Nait 5si remote
handset is described in Section 18 of this manual. A front panel 6.3mm jack socket
enables the use of headphones with the Nait 5si.

Your Nait 5si should be installed on a dedicated equipment stand intended for the
purpose. Do not stand it directly on top of another item of equipment. Care should
be taken to ensure that it is level. The amplifier should be installed in its final location
before connecting cables or switching on. Ensure that the volume is turned down before
switching on.

14.1 Mains Power Connection

Connect the Nait 5si to a mains power socket using either

the mains cable supplied or a Naim Power-Line.

14.2 Signal Inputs

The front panel input selector buttons select the source

input signal to be routed to the power amplifier and

the loudspeakers or headphones. The four buttons
are labelled cd, tuner, hdd (hard disk drive) and av.

Each input button corresponds to a pair of rear panel

RCA phono input sockets. The cd and tuner inputs are

additionally provided with parallel DIN sockets. These

should be used in preference to the RCA phono sockets if

practical. Do not connect both the DIN and RCA phono

sockets of one input simultaneously.

14.3 Speaker Outputs

A stereo set of speaker connection sockets is provided on

the rear panel. The sockets can accept standard 4mm

plugs, but to comply with European legislation the Naim

connectors supplied should be used. Naim Audio speaker

cable will provide the best results; however, a wide

range of speaker cable types can be used without risk of

damage to the amplifier.

14.4 hdd Output

The Nait 5si hdd input has an associated output that

enable the selected input signal to be routed externally; to

an audio recording component for example.

Note: The hdd output remains active regardless of which

input is selected. Take care that a feedback loop is not

inadvertently created by the simultaneous selection of

input and output. The hdd output will be silenced when

the mute is engaged.

14.5 Headphone Output

The Nait 5si headphone output is able to drive the majority

of headphone types. The 6.3mm (1/4”) jack socket, rather

than the smaller 3.5mm jack socket, provides more reliable

connection and potentially higher sound quality. Most

high-quality headphones are supplied with an adaptor

that enables use with either 3.5mm or 6.3mm jack sockets.

Inserting a headphone plug will mute the Nait 5si speaker

outputs. Removing the headphone plug will restore the

outputs.

Ensure when connecting speakers that they are “in

phase”. That is, the positive and negative connection

orientation at both the speaker and amplifier ends of the

cable is the same for both channels.

E16

NAIT 5si

15 Controls and Connections

15.1 Front Panel Controls

volume

15.2 Rear Panel Connections

power

Note: The Nait 5si features various technologies to reduce

microphonic effects. Some movement of the board and

sockets when connecting and disconnecting cables is

normal.

mains

input

and fuse

left

speaker

right

speaker

headphone socket

av in

hdd in

hdd out

source selection

tuner input (RCA phono)

tuner input (DIN)

CD input (RCA
phono)

cd and tuner

ch1
ch2

CD input (DIN)

Inputs

nc
nc

-ve

E17

NAIT 5si

16 Amplifier Operation and Programmable Functions

The Nait 5si incorporates some programmable functions and operational nuances. These
are described in the following paragraphs.

16.1 Automatic Input Switching

With Automatic Input Switching engaged the appropriate

source input will be selected as soon as any handset

function for that (Naim) source component is operated. For

example, if the tuner input is selected and the cd play key

is pressed on the handset, the Nait 5si will automatically

switch to the cd input. Automatic Input Switching can be
programmed to operate on any combination of the cd,

tuner, hdd and av input buttons.

To enable Automatic Input Switching, first switch the Nait 5si

into program mode by pressing and holding the handset

prog key (with the handset in preamplifier mode). The front

panel hdd button will illuminate if automatic switching is

already enabled. If it is not enabled it can be switched on
by pressing the hdd button.

With automatic switching enabled, pressing the hdd button

again will reveal the inputs selected for auto switching

by their indicators illuminating for a short time. Repeated
operation of the hdd button will sequentially select through
each possible combination of cd, tuner, hdd and av inputs

and auto switching disabled (all indicators off). When the

desired inputs selected for auto switching are indicated,

stop pressing the button.

Automatic Input Switching only becomes operational

on exit from program mode by pressing and holding the
handset prog key.

Note: The Nait 5si will leave program mode automatically if

no control commands are received for five minutes.

Note: In a few cases some further equipment configuration

may be required for auto switching to operate correctly.

Please contact your retailer or local distributor for advice.

16.2 AV Bypass

The Nait 5si can be integrated within a multi-channel home

theatre system, driving the front left and right channel

speakers, by engaging its AV Bypass mode. AV Bypass mode

enables a home theatre processor to take over volume
control of signals connected to the Nait 5si av input.

To select AV Bypass, first switch the Nait 5si into program
mode by pressing and holding the handset prog key

(with the handset in preamplifier mode). The front panel

av button will illuminate if AV Bypass is selected. If it is not

enabled it can be switched on by pressing av button

twice.

The Nait 5si volume control indicator will extinguish when

AV Bypass mode is engaged and the av input is selected.

Remote handset volume control and mute function will

also be disabled.

Note: The AV Bypass feature must be used with care. It

bypasses the Nait 5si volume control leaving any signal

connected to the av input to be passed to the speakers at

full volume.

Note: Inserting a headphone plug while AV Bypass mode

is selected temporarily returns the Nait 5si to normal

operation. Removing the headphone plug will return the

Nait 5si to AV Bypass mode.

Note: The mute function is disabled when AV Bypass mode

is engaged.

16.3 Handset Volume Control

The remote handset volume keys provides some

alternative control characteristics. A short press and

release of a key will adjust by a preset “nudge”, while

pressing and holding the key will result in three seconds of

slow adjustment followed by continual fast adjustment.

Note: The Nait 5si does not incorporate any facility for

channel balance adjustment.

16.4 Mute

Mute silences the outputs and can be selected or
deselected by pressing the remote handset mute key.

16.5 Display

The Nait 5si front panel button illumination can be switched

off by pressing the remote handset (in preamplifier mode)

disp function. Any subsequent handset or front panel

operation will temporarily restore the display. A second
operation of the disp function will restore the display.

16.6 Remote Control

The Narcom 4 remote handset supplied with the

Nait 5si duplicates all configuration and control functions.

See Section 18 for more information.

16.7 Defaults

To restore all Nait 5si programmable settings to the factory
defaults press and hold the remote handset disp key while

the unit is in program mode. The Nait 5si will exit from

program mode following this operation.

16.8 Fault Conditions

The Nait 5si will indicate fault conditions by flashing front

panel button buttons. The following table lists the fault

indications.

Fault Flashing Button

Excess Temperature cd

Excess Current tuner

E18

NAIT 5si

17 Specifications

Power Output: 60W + 60W RMS into 8ohms (95W + 95W into 4ohms)
Inputs: 4 analogue line level suitable for 2V sources (0.5V to 7.0V)
Headphones: Front panel 6.3mm (1/4”) jack socket suitable for 16Ω to 1kΩ

headphones

Fixed Line Level Outputs: ‘hdd out’
Quiescent Consumption: 19VA
Dimensions (H x W x D): 70 x 432 x 301mm
Weight: 6.8kg
Mains Supply: 100V, 115V or 230V, 50/60Hz

For full technical specifications please visit our website:

http://www.naimaudio.com/hifi-products/nait-5si

E19

NARCOM 4 Remote Handset

18 NARCOM 4 Remote Handset

The Narcom 4 remote handset is supplied with the Supernait 2, Nait XS 2 and Nait 5si. It
is a multi-functional remote control handset designed to be used with Naim Audio CD
players, integrated amplifiers, preamplifiers, and preset tuners.

To fit the remote handset batteries, remove the battery cover by pressing the small button
located on the rear of the handset body. Remove the cover and insert the batteries into
the body taking care with their orientation. Replace the battery cover.

18.1 Using NARCOM 4

Operation of the Narcom 4 handset is based around three
types of keys: System Component Keys, Global Keys and

Soft Keys.

System Component Keys switch the operation of the Soft
Keys into modes appropriate to each system component

(CD player, preamplifier, etc.).

Global Keys operate specific component functions

regardless of the System Component Key setting and are

available at all times.

18.1.1 Integrated Amplifier Global Keys operate as
follows:

vol (5 & 6) Adjusts the volume and the volume control

position.

mute Reduces volume to zero. A second press

restores the volume.

bal (3 & 4) Adjusts the channel balance.

Note: The Nait XS 2 and Nait 5si do not incorporate any

facility for channel balance adjustment.

18.1.2 Integrated Amplifier Soft Keys operate as
described below:

Note: The handset must be in preamp mode. Press the

“pre” key.

18.2 NARCOM 4 Keys

Disp Key (soft)

Numeric keys (soft)

System Component Keys

Global Keys (CD)

Volume and mute keys

Prog Key (soft)

Balance Keys

Global Keys (product specific)

disp Switches the front panel button indicators

off and on.

prog Press and hold to switch the preamplifier or

integrated amplifier into program mode.

numeric Enables direct selection of source inputs.

1, 2 , 3, 4, 5 and 6 correspond to the cd,

tuner, av, hdd, aux 1 and aux 2 inputs

respectively.

E20

Declaration of Conformity

19 Declaration of Conformity

Naim Audio declares that Naim Audio products are in conformance with:
Low Voltage Directive 2006/95/EC
Electromagnetic Compatibility Directive 2004/108/EC
Restriction of Hazardous Substances (RoHS2) Directive 2011/65/EU
Waste of Electrical and Electronic Equipment Directive 2002/96/EC
Energy Using Product Directive 2005/32/EC

Naim Audio products comply with the following standards:
EN60065 - Audio, video and similar electronic apparatus - Safety requirements
EN55013 - Sound and television broadcast receivers and associated equipment - Radio
disturbance characteristics
EN55020 - Sound and television broadcast receivers and associated equipment - Immunity
characteristics
EN61000-3-2 - Mains harmonics current emissions
EN61000-3-3 - Main flicker emissions

20 Statutory Safety Warnings

In order to comply with current European safety regulations
it is essential that the Naim loudspeaker connectors
supplied with amplifiers and loudspeakers are used.

Do not under any circumstances allow anyone to modify
your Naim equipment without first checking with the
factory, your retailer, or your distributor. Unauthorised
modifications will invalidate your guarantee.

Equipment must not be exposed to dripping or splashing
and no objects filled with liquid, such as vases, should be
placed on the equipment.

For your own safety do not under any circumstances open
Naim equipment without first disconnecting it from the
mains.

Warning: an apparatus with CLASS I construction shall be
connected to a mains socket outlet with a protective
earthing connection.

Warning: batteries installed shall not be exposed to
excessive heat such as sunshine, fire or the like.

Where the mains plug or an appliance coupler is used as
the disconnect device, the disconnect device shall remain
readily operable. To disconnect the equipment from the
mains remove the mains plug from the mains outlet.

The following label is attached to all mains powered
equipment:

WARNING

THIS APPARATUS

MUST BE EARTHED

This equipment has been tested and found to comply
with the relevant EMC and Safety Standards, and, where
applicable, also complies with the limits for a class B digital
device, pursuant to Part 15 of the FCC Rules.

These limits are designed to provide reasonable protection
against harmful interference in a residential installation.
This equipment generates, uses and can radiate radio
frequency and, if not installed and used in accordance
with the instructions, may cause harmful interference to
radio communications. However, there is no guarantee that
interference will not occur in a particular installation. If this
equipment does cause harmful interference to radio or
television reception, which can be determined by turning
off and on, the user is encouraged to try to correct the
interference by one or more of the following measures:

• Reorient or relocate the receiving antenna.

• Increase the separation between the equipment and the

receiver.

• Connect the equipment into an outlet on a circuit

different from that to which the receiver is connected.

• Consult your Naim retailer or an experienced radio/TV

technician for help.

Note

To the fullest extent permitted by applicable law, Naim
Audio Ltd. disclaims all liability for any loss or damages
whether real, incidental or consequential that arise from
using this product. Naim Audio Limited, its agents and
representatives, cannot be held responsible for the loss of
any data or content from a Naim/NaimNet server, however
caused.

Naim Audio Ltd, Southampton Road, Salisbury, England SP1 2LN
Tel: [phone] Fax: [phone]
W: www.naimaudio.com
Part No. 12-001-0221 Iss. 1K

Products that display the crossed-out wheeled bin logo
cannot be disposed of as domestic waste. These products
must be disposed of at facilities capable of re-cycling
them and appropriately handling any waste
by-products. Contact your local authority for
details of the nearest such facility. Appropriate
recycling and waste disposal helps conserve
resources and protects the environment from
contamination.

E21