NAD M28 User manual

Owner’s Manual
Seven Channel Power Amplier
®
M28
© NAD M28
ENGLISHFRANÇAISESPAÑOLITALIANODEUTSCHNEDERLANDSSVENSKAРУССКИЙ

ENGLISH
2
• Read instructions - All the safety and operating instructions should be read
before the product is operated.
• Retain instructions - The safety and operating instructions should be retained
for future reference.
• Heed Warnings - All warnings on the product and in the operating instructions
should be adhered to.
• Follow Instructions - All operating and use instructions should be followed.
• Cleaning - Unplug this product from the wall outlet before cleaning. Do not use
liquid cleaners or aerosol cleaners. Use a dry cloth for cleaning.
• Attachments - Do not use attachments not recommended by the product
manufacturer as they may cause hazards.
• Water and Moisture - Do not use this product near water-for example, near a
bath tub, wash bowl, kitchen sink, or laundry tub; in a wet basement; or near a
swimming pool; and the like.
• Accessories - Do not place this product on an unstable cart, stand, tripod,
bracket, or table. The product may fall, causing serious injury to a child or adult
and serious damage to the product. Use only with a cart, stand, tripod, bracket,
or table recommended by the manufacturer, or sold with the product. Any
mounting of the product should follow the manufacturer’s instructions, and
should use a mounting accessory recommended by the manufacturer.
• Cart - A product and cart combination should be moved with care.
Quick stops, excessive force, and uneven surfaces may cause the
product and cart combination to overturn.
• Ventilation - Slots and openings in the cabinet are provided for ventilation
to ensure reliable operation of the product and to protect it from overheating.
These openings must not be blocked or covered. The openings should never be
blocked by placing the product on a bed, sofa, rug, or other similar surface. This
product should not be placed in a built-in installation such as a bookcase or rack
unless proper ventilation is provided or the manufacturer’s instructions have been
adhered to.
• Power Sources - This product should be operated only from the type of power
source indicated on the marking label and connected to a MAINS socket outlet
with a protective earthing connection. If you are not sure of the type of power
supply to your home, consult your product dealer or local power company.
• Power–Cord Protection - Power-supply cords should be routed so that they
are not likely to be walked on or pinched by items placed upon or against them,
paying particular attention to cords at plugs, convenience receptacles, and the
point where they exit from the product.
• Mains Plug - Where the mains plug or an appliance coupler is used as the
disconnect device, the disconnect device shall remain readily operable.
• Outdoor Antenna Grounding - If an outside antenna or cable system is
connected to the product, be sure the antenna or cable system is grounded so
as to provide some protection against voltage surges and built-up static charges.
Article 810 of the National Electrical Code, ANSI/NFPA 70, provides information
with regard to proper grounding of the mast and supporting structure, grounding
of the lead-in wire to an antenna discharge unit, size of grounding conductors,
location of antenna discharge unit, connection to grounding electrodes, and
requirements for the grounding electrode.
• Lightning - For added protection for this product during a lightning storm, or
when it is left unattended and unused for long periods of time, unplug it from the
wall outlet and disconnect the antenna or cable system. This will prevent damage
to the product due to lightning and power-line surges.
• Power Lines - An outside antenna system should not be located in the vicinity
of overhead power lines or other electric light or power circuits, or where it can
fall into such power lines or circuits. When installing an outside antenna system,
extreme care should be taken to keep from touching such power lines or circuits
as contact with them might be fatal.
• Overloading - Do not overload wall outlets, extension cords, or integral
convenience receptacles as this can result in a risk of re or electric shock.
• Flame Sources - No naked ame sources, such as lighted candles, should be
placed on the product.
• Object and Liquid Entry - Never push objects of any kind into this product
through openings as they may touch dangerous voltage points or short-out parts
that could result in a re or electric shock. Never spill liquid of any kind on the
product.
• Headphones - Excessive sound pressure form earphones and headphones can
cause hearing loss.
• Damage Requiring Service - Unplug this product from the wall outlet and refer
servicing to qualied service personnel under the following conditions:
– When the power-supply cord or plug is damaged.
– If liquid has been spilled, or objects have fallen into the product.
– If the product has been exposed to rain or water.
– If the product does not operate normally by following the operating
instructions. Adjust only those controls that are covered by the operating
instructions as an improper adjustment of other controls may result in
damage and will often require extensive work by a qualied technician to
restore the product to its normal operation.
– If the product has been dropped or damaged in any way.
– When the product exhibits a distinct change in performance-this indicates a
need for service.
• Replacement Parts - When replacement parts are required, be sure the service
technician has used replacement parts specied by the manufacturer or have the
same characteristics as the original part. Unauthorized substitutions may result in
re, electric shock, or other hazards.
• Battery Disposal - When disposing of used batteries, please comply with
governmental regulations or environmental public instruction’s rules that apply in
your country or area.
• Safety Check - Upon completion of any service or repairs to this product, ask the
service technician to perform safety checks to determine that the product is in
proper operating condition.
WARNING
The lightning ash with arrowhead symbol, within an equilateral
triangle, is intended to alert the user to the presence of uninsulated
“dangerous voltage” within the product’s enclosure that may be of
sucient magnitude to constitute a risk of electric shock to persons
The exclamation point within an equilateral triangle is intended to alert the user to
the presence of important operating and maintenance (servicing)
instructions in the literature accompanying the appliance.
CAUTION REGARDING PLACEMENT
To maintain proper ventilation, be sure to leave a space around the unit (from the
largest outer dimensions including projections) than is equal to, or greater than
shown below.
Left and Right Panels: 10 cm
Rear Panel: 10 cm
Top Panel: 10 cm
Do not install near any heat sources such as radiators, heat registers, stoves, or other
apparatus (including ampliers) that produce heat.
Do not defeat the safety purpose of the polarized or grounding - type plug. A
polarized plug has two blades with one wider than the other. A grounding type plug
has two blades and a third grounding prong. The wide blade or the third prong is
provided for your safety. When the provided plug does not t into your outlet, consult
an electrician for replacement of the obsolete outlet.
The apparatus should only be used in moderate climates.
IMPORTANT SAFETY INSTRUCTIONS

ENGLISH
NAD is a trademark of NAD Electronics International, a division of Lenbrook Industries Limited
Copyright 2020, NAD Electronics International, a division of Lenbrook Industries Limited
3
FCC STATEMENT
This equipment has been tested and found to comply with the limits for 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
energy 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 the equipment o 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 receiver.
• Connect the equipment into an outlet on a circuit dierent from that to which
the receiver is connected.
• Consult the dealer or an experienced radio TV technician for help.
CAUTION
• Changes or modications to this equipment not expressly approved by NAD
Electronics for compliance could void the user’s authority to operate this equipment.
• To prevent electric shock, match wide blade of plug to wide slot, fully insert.
• Marking and rating plate can be found at the rear panel of the apparatus.
• To reduce the risk of re or electric shock, do not expose this apparatus to rain or
moisture. The apparatus shall not be exposed to dripping or splashing and that
no objects lled with liquids, such as vases, shall be placed on apparatus.
• Mains plug is used as disconnect device and it should remain readily operable during
intended use. In order to disconnect the apparatus from the mains completely, the
mains plug should be disconnected from the mains socket outlet completely.
• An appliance with a protective earth terminal should be connected to a mains
outlet with a protective earth connection.
RESPONSIBLE PARTY
Lenbrook International
633 Granite Court
Pickering, ON L1W 3K1
Canada
Tel: [phone]
IF IN DOUBT CONSULT A COMPETENT ELECTRICIAN.
This product is manufactured to comply with the radio interference
requirements of EEC DIRECTIVE 2004/108/EC.
NOTES ON ENVIRONMENTAL PROTECTION
At the end of its useful life, this product must not be disposed of with
regular household waste but must be returned to a collection point for
the recycling of electrical and electronic equipment. The symbol on the
product, user’s manual and packaging point this out.
The materials can be reused in accordance with their markings. Through
re-use, recycling of raw materials, or other forms of recycling of old products, you are
making an important contribution to the protection of our environment.
Your local administrative oce can advise you of the responsible waste disposal point.
INFORMATION ABOUT COLLECTION AND DISPOSAL OF WASTE BATTERIES
DIRECTIVE 2006/66/EC OF THE EUROPEAN PARLIAMENT AND THE COUNCIL
OF EUROPEAN UNION FOR EUROPEAN CUSTOMERS ONLY
Batteries bearing any of these symbols indicate that
they should be treated as “separate collection”and not
as municipal waste. It is encouraged that necessary
measures are implemented to maximize the separate
collection of waste batteries and to minimize the
disposal of batteries as mixed municipal waste.
End-users are exhorted not to dispose waste batteries
as unsorted municipal waste. In order to achieve a high
level of recycling waste batteries, discard waste batteries
separately and properly through an accessible collection
point in your vicinity. For more information about collection and recycling of waste
batteries, please contact your local municipality, your waste disposal service or the
point of sale where you purchased the items.
By ensuring compliance and conformance to proper disposal of waste batteries,
potential hazardous eects on human health is prevented and the negative impact of
batteries and waste batteries on the environment is minimized, thus contributing to
the protection, preservation and quality improvement of the environment.
IMPORTANT SAFETY INSTRUCTIONS

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WHAT’S IN THE BOX
Packed with your M28 you will nd
• A detachable mains power cord
• Four pieces of magnetic feet
• Cleaning cloth
• Quick Setup Guide
QUICK SETUP GUIDE
In case you simply cannot wait to experience the performance of your
new NAD M28 Seven Channel Power Amplier, the following QUICK SETUP
GUIDE is recommended to help you get started.
Ensure that the M28 is unplugged before making any connections. It is
also advisable to power-down or unplug all associated components while
making or breaking any signal or AC power connections.
1 Set the external source's volume control to minimum level. External
source can be a preamplier, processor, amplier or any applicable
device.
2 Set SELECT switch to BALANCED or SINGLE-ENDED. Connect the analog
audio output of your external source to the M28 rear panel’s BALANCED
or SINGLE-ENDED analog audio input. Depending upon the source’s
conguration, analog audio input connection can be made up to seven
channels either via BALANCED or SINGLE-ENDED input ports.
3 Connect your speakers to the SPEAKER terminals of M28. Note
suggested speaker connections as reected in the rear panel channel
allocations.
4 Plug-in to a mains power source the M28’s supplied mains power cord.
Connect corresponding end of the mains power cord to the AC mains
input of M28 and the plug connected to a mains power source.
5 Plug-in also to a mains power source the external source’s mains power
cord. Power up the external source ahead of the M28.
6 Set to ON the rear panel POWER switch of M28. The M28 goes to
standby mode as shown by the amber status condition of the Power
indicator.
7 Press o(Standby) button for the M28 to be switched ON from standby
mode. The Power indicator will turn from amber to bright/white color.
The M28 is ready for operation.
8 Adjust the external source’s volume control according to desired
listening level.
SAVE THE PACKAGING
Please save the box and all of the packaging in which your M28 arrived.
Should you move or otherwise need to transport your M28, this is by far
the safest container in which to do so. We’ve seen too many otherwise
perfect components damaged in transit for lack of a proper shipping
carton, so please: Save that box!
NOTES ON INSTALLATION
• Your NAD M28 should be placed on a rm, level surface.
• Avoid placing the unit in direct sunlight or near sources of heat and
damp.
• Allow adequate ventilation.
• Do not place the unit on a soft surface like a carpet.
• Avoid placing the M28 inside a closed cabinet that is not well ventilated
as this may compromise the M28’s performance and reliability.
• Ensure that the M28 is unplugged before making any connections.
• For best performance, use quality speaker leads of 16 gauge (1.5mm2)
thickness or more.
• If the unit is not going to be used for some time, disconnect the plug
from the mains power source.
• Use a dry cloth for cleaning.
DO NOT REMOVE THE COVER; THERE ARE NO USERSERVICEABLE
PARTS INSIDE.
BARE WIRES AND PIN CONNECTORS
WARNING: The terminals marked with this symbol
are hazardous live. External wiring connected to these
terminals requires installation by an instructed person or
the use of ready-made leads or cords.
Bare wires and pin sockets should be inserted into the hole in the shaft
of the terminal. Unscrew the speaker terminal’s plastic bushing until the
hole in the screw shaft is revealed. Insert the pin or bare cable end into
the hole and secure the cable by tightening down the terminal’s bushing.
Ensure bare wire from the speaker cables does not touch the back panel or
another socket. Ensure that there is only 1/2”(1cm) of bare cable or pin and
no loose strands of speakers wire.
FEET INSTALLATION
The supplied magnetic feet can be easily installed by aligning and attaching
them to their corresponding foot shoe. Refer to illustration below.
INTRODUCTION
GETTING STARTED
^

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5
IDENTIFICATION OF CONTROLS
FRONT PANEL
1 o(STANDBY)
• Press o(Standby) button for the M28 to be switched ON from
standby mode. The Power indicator will turn from amber to bright/
white color.
• Press and hold o(Standby) button until M28 switches back to
standby mode. The Power indicator will illuminate to amber color at
standby mode.
• The o(Standby) button cannot activate the M28 with the rear
panel POWER switched o.
IMPORTANT NOTE
For the o(Standby) button to activate, two conditions must be
completed.
• Plug-in the supplied mains power cord to a mains power source.
Connect corresponding end of the mains power cord to the AC mains
input of M28 and the plug connected to a mains power source.
• The rear panel POWER switch must be set to ON position.
AUTO STANDBY
The M28 can be setup to automatically go to standby mode if there is no
active source input within 30 minutes. Auto standby mode can be enabled
or disabled by the following steps.
Enable Auto Standby mode
• With M28 at operating mode, press and hold the LED LEVEL button until
the Power indicator (NAD logo) ashes once.
• At operating mode, the M28 will automatically go to standby mode if
there is no active source input within 30 minutes.
Disable Auto Standby mode
• With M28 at operating mode, press and hold the LED LEVEL button until
the Power indicator (NAD logo) ashes twice.
• At operating mode, M28 will not automatically go to standby mode
even if there is no active source input within 30 minutes. Press oto
switch M28 from operating mode to standby mode.
2 POWER INDICATOR (NAD LOGO)
• The NAD logo in the front panel also serves as a Power indicator.
• Power indicator colors
Bright/white - Normal operating mode
Amber - Standby mode
Red - Protect mode
© NAD M28
1
2

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6
1 BALANCED
• Use the BALANCED analog audio input of the M28 if the external
source to be connected has BALANCED audio output. Superior
audio quality is ensured with the distinctive noise reduction
capability of BALANCED connection with XLR jacks.
• With BALANCED as the selected audio input, ensure that SELECT
switch is set to BALANCED.
• For optimum heat dissipation in an AV surround system, the
following audio channel allocations are recommended:
Channel 1 = Front Left speaker
Channel 2 = Surround Left speaker
Channel 3 = Surround Back Left speaker
Channel 4 = Center speaker
Channel 5 = Surround Back Right speaker
Channel 6 = Surround Right speaker
Channel 7 = Front Right speaker
PIN CONFIGURATION OF BALANCED XLR JACK
Pin 1: Ground
Pin 2: Positive (signal live)
Pin 3: Negative (signal return)
IMPORTANT NOTES
• Always turn OFF the M28 and other components in the system before
connecting or disconnecting anything to the BALANCED audio input
jacks.
• Before switching ON the M28 from standby mode for the rst time,
make sure that the volume control of the external source is set to
minimum level position. This prevents inadvertently beginning a session
at excessive volume.
· Depending upon the source’s conguration, analog audio input
connection can be made up to seven channels either via BALANCED or
SINGLE-ENDED input ports.
2 SINGLE-ENDED
• Use single-ended analog audio input for sources (preampliers or
processors) that are not equipped with BALANCED analog audio
output.
• With SINGLE-ENDED as the selected audio input, ensure that
SELECT switch is set to SINGLE-ENDED.
3 PROTECT
• When a specic channel goes to protect mode, the corresponding
PROTECT LED will turn red. The other ampliers that did not go
to protect mode will continue to function as indicated by their
respective PROTECT LEDs illuminated in green.
PROTECT LED INDICATOR COLORS
CONDITION PROTECT LED COLOR POWER INDICATOR (NAD
LOGO) COLOR
Normal operation Green Bright/white
Overheat
Red (per applicable channels;
other channels may remain
green)
Bright/white
Short circuit No light (all channels) Red
IDENTIFICATION OF CONTROLS
REAR PANEL
© NAD M28
SELECT
BALANCED
SINGLE-ENDED
PROTECT
ANALOG AUDIO INPUT
SELECT
BALANCED
SINGLE-ENDED
PROTECT
ANALOG AUDIO INPUT
SELECT
BALANCED
SINGLE-ENDED
PROTECT
ANALOG AUDIO INPUT
SELECT
BALANCED
SINGLE-ENDED
PROTECT
ANALOG AUDIO INPUT
SELECT
BALANCED
SINGLE-ENDED
PROTECT
ANALOG AUDIO INPUT
SELECT
BALANCED
SINGLE-ENDED
PROTECT
ANALOG AUDIO INPUT
SELECT
BALANCED
SINGLE-ENDED
PROTECT
ANALOG AUDIO INPUT
POWER
ON
SPEAKER SPEAKER SPEAKER SPEAKER SPEAKER SPEAKER SPEAKER
4 5 6 7
8 9 10
1 2 3
ATTENTION!
Ensure that the M28 is unplugged before making any connections. It is also advisable to power-down or unplug all associated components while making
or breaking any signal or AC power connections.

ENGLISH
7
PROTECT MODE
If one or more PROTECT LEDs turn red or become all extinguished, this
indicates that the protection circuitry of the M28 had been engaged.
Immediately press the Standby button, turn o Power switch and then
unplug the mains power cord from the mains power source. Undertake
the following
a Check if all speaker wires are connected correctly and that none of
the wires are damaged, causing a short circuit.
b Another cause may be excessive heat build-up inside the amplier.
Make sure there is adequate ventilation around the amplier and
that none of its ventilation slots, top or bottom are blocked. After
the amplier has cooled down, it will function normally again.
c In case one or more of the PROTECT LEDs or Power indicator remained
illuminated in red despite the checks mentioned above, immediately
press the Standby button, turn o Power switch and then unplug the
mains power cord from the mains power source. Have the unit inspected
by a qualied service technician before attempting to use it again.
4 SELECT
• Use this switch to select the type of analog audio input.
• SELECT switch settings
Upper position – SINGLE-ENDED input is selected.
Lower position – BALANCED input is selected.
WARNING!
Do not adjust the SELECT switch while the M28 is at operating mode.
Use SELECT switch to choose BALANCED or SINGLE-ENDED only when
the M28 is at standby mode or powered down.
5 +12V TRIGGER IN
• The +12V Trigger input allows the M28 to be switched remotely
from standby mode to ON and vice-versa by an ancillary equipment
such as a preamplier, AV processor, etc. The controlling device
must be equipped with a 12V trigger output to use this feature.
WARNING
The front panel o(Standby) button is disabled as long as the male plug
of the mono cable (with or without +12V DC) is connected to M28’s
+12V TRIGGER IN. Unplug the mono cable for the M28 to be normally
switched ON (or back to standby mode) using the front panel o
(Standby) button.
6 LED LEVEL (DIMMER)
• Toggle to reduce or restore Power indicator brightness or
completely turn it o.
7 FUSE HOLDER
• In the unlikely event a fuse needs to be replaced, unplug the mains
power cord from the wall. Then, remove all connections from the
amplier. Use a athead screw driver or similar to open the fuse
holder via the slot indicated. With the screw driver in place, push
and turn counterclockwise to open the fuse holder.
• Only replace the fuse with the same type, size, and specication.
IMPORTANT NOTICE
Do not use any substitute fuses of dierent types or with dierent
ratings or values. Failure to observe this precaution may cause damage
to the amplier circuits and may create a re hazard and/or defeat the
safety built into the amplier and may void the warranty.
8 SPEAKER
• The M28 is equipped with gold-plated, color-coded, transparent
and special high-current binding-post speaker terminals.
• Connect FRONT L, FRONT R, CENTER, SURR R, SURR L, SURR-BL and
SURR-BR speaker terminals to corresponding speakers. Make sure
the “+” (red) terminal and“-”(black) terminal are connected to the
corresponding “+”and“-”terminals of the speaker. Use extra care
to ensure that no stray wires or strands cross between posts or
terminals at either end.
• The M28 is designed to produce optimum sound quality when
connected to speakers with impedances within its operating range.
Please make sure that all the speakers are rated 4 ohms minimum
per speaker.
NOTE
Use stranded wire of at least 16 gauge (AWG). Connections to the M28
can be made with banana plugs or by using bare wire or pins. Use the
transverse hole through the post for bare-wire or pin connections. By
loosening the terminal’s plastic nut, make a clean, neat connection and
re-tighten carefully. To minimize the danger of short-circuit, ensure that
only 1/2-inch of exposed wire or pin is employed when connecting.
9 POWER
• Supply the AC mains power to the M28.
• When the POWER switch is set to ON position, the M28 goes to
standby mode as shown by the amber status condition of the
Power indicator. Press o(Standby) button to switch ON the M28
from standby mode.
• If you intend not to use the M28 for long periods of time (such as
when on vacation), switch o the POWER switch.
• The o(Standby) button cannot activate the M28 with the rear
panel POWER switched o.
10 AC MAINS INPUT
• The M28 comes supplied with two types of detachable mains
power cord. Select applicable type for your usage. Connect
corresponding end of the mains power cord to the AC mains input
of M28 and the plug connected to a mains power source.
• Always disconnect the mains power plug from the mains power
source rst, before disconnecting the cable from the M28’s AC
Mains input socket
IDENTIFICATION OF CONTROLS
REAR PANEL
© NAD M28
SELECT
BALANCED
SINGLE-ENDED
PROTECT
ANALOG AUDIO INPUT
SELECT
BALANCED
SINGLE-ENDED
PROTECT
ANALOG AUDIO INPUT
SELECT
BALANCED
SINGLE-ENDED
PROTECT
ANALOG AUDIO INPUT
SELECT
BALANCED
SINGLE-ENDED
PROTECT
ANALOG AUDIO INPUT
SELECT
BALANCED
SINGLE-ENDED
PROTECT
ANALOG AUDIO INPUT
SELECT
BALANCED
SINGLE-ENDED
PROTECT
ANALOG AUDIO INPUT
SELECT
BALANCED
SINGLE-ENDED
PROTECT
ANALOG AUDIO INPUT
POWER
ON
SPEAKER SPEAKER SPEAKER SPEAKER SPEAKER
SPEAKER SPEAKER
© NAD M28
SELECT
BALANCED
SINGLE-ENDED
PROTECT
ANALOG AUDIO INPUT
SELECT
BALANCED
SINGLE-ENDED
PROTECT
ANALOG AUDIO INPUT
SELECT
BALANCED
SINGLE-ENDED
PROTECT
ANALOG AUDIO INPUT
SELECT
BALANCED
SINGLE-ENDED
PROTECT
ANALOG AUDIO INPUT
SELECT
BALANCED
SINGLE-ENDED
PROTECT
ANALOG AUDIO INPUT
SELECT
BALANCED
SINGLE-ENDED
PROTECT
ANALOG AUDIO INPUT
SELECT
BALANCED
SINGLE-ENDED
PROTECT
ANALOG AUDIO INPUT
POWER
ON
SPEAKER SPEAKER SPEAKER SPEAKER SPEAKER SPEAKER SPEAKER
2 CHANNEL AUDIO OUT
UNBALANCED
RBALANCED
DIGITAL AUDIO OUTPUT
AES/EBU
S-VIDEO OUT
LBALANCED
L
R
POWER
ON
COMPONENT VIDEO OUT
AUDIO OUT
L R
HDMI OUT1 HDMI OUT2 HDMI OUT1 HDMI OUT2
12V IN
12V OUT
DIGITAL AUDIO OUT
OPTICAL COAXIAL
COMPONENT VIDEO OUT
COMPONENT VIDEO OUT
12V IN
12V OUT
DIGITAL AUDIO OUT
OPTICAL
COAXIAL
POWER
ON
100-240V ~ 50/60Hz

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8
CONDITION POSSIBLE CAUSES POSSIBLE SOLUTIONS
No power. • Mains power cord unplugged from mains
power source or from M28’s AC mains input.
• Connect the mains power cord to M28’s
AC mains input and then plug into a mains
power source.
• Power switch is o. • Switch ON the Power switch.
• M28 at standby mode. • Press o(Standby) button to switch ON the
M28 from standby mode.
M28 always at standby mode; cannot be
switched ON using the o(Standby) button.
• A mono plug is plugged-in at the +12V
TRIGGER IN port of the rear panel.
• Unplug the mono plug.
No sound. • No input signal applied through the analog
audio input ports.
• Check that there is active input signal applied
through the analog audio input ports.
• External source volume control is set to
minimum level.
• Turn up external source’s volume control until
audio is heard.
No sound one channel. • Speaker not properly connected or damaged. • Check connections and speakers.
• Input lead disconnected or damaged. • Check leads and connections.
There is no BALANCED audio output. • SELECT switch is set to SINGLE-ENDED. • Set SELECT switch to BALANCED.
There is no SINGLE-ENDED audio output. • SELECT switch is set to BALANCED. • Set SELECT switch to SINGLE-ENDED.
REFERENCE
TROUBLESHOOTING

ENGLISH
9
All specs are measured according to IHF 202 CEA 490-AR-2008 standard. THD is measured using AP AUX 0025 passive lter and AES 17 active lter.
OVERALL SPECIFICATION
FTC power, two channels ≥ 220 W (ref. ratedTHD, 8 ohms, 1kHz, two channels driven)
≥ 400 W (ref. ratedTHD, 4 ohms, 1kHz, two channels driven)
Rated power, all channels ≥ 200 W (ref. ratedTHD, 8 ohms, 20 Hz - 20 kHz, all channels driven)
≥ 340 W (ref. ratedTHD, 4 ohms, 20 Hz - 20 kHz, all channels driven)
RatedTHD (CCIF IMD, DIM 100) ≤ 0.003 % (ref. 20 Hz - 20 kHz, 250 mW to rated power)
≤ 0.0005 % (ref. 20 Hz - 20 kHz, 1/2 rated power)
IHF dynamic power 280 W (8 ohms, all channels driven)
560 W (4 ohms, 2 channel driven)
500 W (2 ohms, 2 channel driven)
Damping factor > 750 (ref. 8 ohms, 50 Hz and 1 kHz)
Input sensitivity 1.3 V (ref. rated power)
Input impedance 47 kohms (Balanced)
23 kohms (Single-ended)
Signal/noise ratio > 102dB (A-weighted ref. 1W, Balanced)
> 97 dB (A-weighted ref. 1W, Single-ended)
> 124 dB (A-weighted ref. rated power, Balanced)
> 120 dB (A-weighted ref. rated power, Single-ended)
Frequency response ± 0.1 dB (ref. 20 Hz - 20 kHz)
- 3 dB at 3 Hz to 60 kHz
Voltage gain 29.5 dB ±0.3 dB
Time to go to Standby mode at no input signal ≤ 30 minutes
Standby power ≤ 0.5W
DIMENSION AND WEIGHT
Gross dimension (W x H x D)* 435 x 156 x 380 mm
17 ⁄ x 6 ⁄ x 15 inches
Shipping weight 21.2 kg (46.7 lbs)
* - Gross dimension includes extended rear panel terminals and installed feet
Specifications are subject to change without notice. Check out www.NADelectronics.com for updated documentation or latest information about M28.
REFERENCE
SPECIFICATIONS

www.NADelectronics.com
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While every effort has been made to ensure the contents are accurate at the time of publication, features and specifications may be subject to change without prior notice.
M28OMENV04  JUL 2020