WARNING: This symbol, D, when used on the product, is intended
to alert the user of the presence of uninsulated dangerous voltage
within the product’s enclosure that may present a risk of electric
shock.
ATTENTION: This symbol, I, when used on the product, is
intended to alert the user of important operating and maintenance
(servicing) instructions in the literature provided with the equipment.
For information on safety guidelines, regulatory compliances, EMI/EMF
compatibility, accessibility, and related topics, see the Extron Safety and
Regulatory Compliance Guide, part number 68-290-01, on the Extron
website, www.extron.com.
Instructions de sécurité • Français
AVERTISSEMENT: Ce pictogramme, D, lorsqu’il est utilisé sur
le produit, signale à l’utilisateur la présence à l’intérieur du boîtier
du produit d’une tension électrique dangereuse susceptible de
provoquer un choc électrique.
ATTENTION: Ce pictogramme, I, lorsqu’il est utilisé sur le
produit, signale à l’utilisateur des instructions d’utilisation ou de
maintenance importantes qui se trouvent dans la documentation
fournie avec le matériel.
Pour en savoir plus sur les règles de sécurité, la conformité à la
réglementation, la compatibilité EMI/EMF, l’accessibilité, et autres sujets
connexes, lisez les informations de sécurité et de conformité Extron,
réf. 68-290-01, sur le site Extron, www.extron.com.
Sicherheitsanweisungen • Deutsch
WARNUNG: Dieses Symbol D auf dem Produkt soll den Benutzer
darauf aufmerksam machen, dass im Inneren des Gehäuses dieses
Produktes gefährliche Spannungen herrschen, die nicht isoliert sind
und die einen elektrischen Schlag verursachen können.
Инструкция по технике безопасности • Русский
ПРЕДУПРЕЖДЕНИЕ: Данный символ, D, если указан
на продукте, предупреждает пользователя о наличии
неизолированного опасного напряжения внутри корпуса
продукта, которое может привести к поражению
электрическим током.
ВНИМАНИЕ: Данный символ, I, если указан на продукте,
предупреждает пользователя о наличии важных инструкций
по эксплуатации и обслуживанию в руководстве,
прилагаемом к данному оборудованию.
Для получения информации о правилах техники безопасности,
соблюдении нормативных требований, электромагнитной
совместимости (ЭМП/ЭДС), возможности доступа и других вопросах
см. руководство по безопасности и соблюдению нормативных
требований Extron на сайте Extron: www.extron.com, номер по
каталогу - 68-290-01.
VORSICHT: Dieses Symbol I auf dem Produkt soll dem Benutzer in
der im Lieferumfang enthaltenen Dokumentation besonders wichtige
Hinweise zur Bedienung und Wartung (Instandhaltung) geben.
Weitere Informationen über die Sicherheitsrichtlinien, Produkthandhabung,
EMI/EMF-Kompatibilität, Zugänglichkeit und verwandte Themen finden Sie
in den Extron-Richtlinien für Sicherheit und Handhabung (Artikelnummer
68-290-01) auf der Extron-Website, www.extron.com.
Instrucciones de seguridad • Español
ADVERTENCIA: Este símbolo, D, cuando se utiliza en el producto,
avisa al usuario de la presencia de voltaje peligroso sin aislar dentro
del producto, lo que puede representar un riesgo de descarga
eléctrica.
ATENCIÓN: Este símbolo, I, cuando se utiliza en el producto, avisa
al usuario de la presencia de importantes instrucciones de uso y
mantenimiento recogidas en la documentación proporcionada con
el equipo.
Para obtener información sobre directrices de seguridad, cumplimiento
de normativas, compatibilidad electromagnética, accesibilidad y
temas relacionados, consulte la Guía de cumplimiento de normativas
y seguridad de Extron, referencia 68-290-01, en el sitio Web de Extron,
『Extron Safety and Regulatory Compliance Guide』 (P/N 68-290-01) をご覧く
ださい。
Korean
경고: 이 기호 D, 가 제품에 사용될 경우, 제품의 인클로저 내에 있는
접지되지 않은 위험한 전류로 인해 사용자가 감전될 위험이 있음을
경고합니다.
주의: 이 기호 I, 가 제품에 사용될 경우, 장비와 함께 제공된 책자에 나와
있는 주요 운영 및 유지보수(정비) 지침을 경고합니다.
안전 가이드라인, 규제 준수, EMI/EMF 호환성, 접근성, 그리고 관련 항목에 대한
자세한 내용은 Extron 웹 사이트(www.extron.com)의 Extron 안전 및 규제 준수
안내서, 68-290- 01 조항을 참조하십시오.
FCC Class B Notice
ClassB digital device, pursuant to part15 of the FCC rules. These limits 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. There is no guarantee that interference will not occur. If this equipment
does cause interference to radio or television reception, which can be determined by turning
the equipment off and on, you are 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 different from that to which the
receiver is connected.
• Consult the dealer or an experienced radio/TV technician for help.
This equipment has been tested and found to comply with the limits for a
NOTE: For more information on safety guidelines, regulatory compliances, EMI/
EMF compatibility, accessibility, and related topics, see the Extron Safety and
Regulatory Compliance Guide on the Extron website.
Back of the Rack Mounting .......................... 15
Other Mounting Options ................................... 15
MPA 152 Plus • Contentsv
MPA 152 Plus • Contentsvi
Introduction
This manual contains information about the Extron MPA 152 Plus mini power amplifier
with instructions for experienced installers on how to install, configure, and operate the
equipment. Unless otherwise specified, in this manual “amplifier” or “MPA” refer to the
MPA152 Plus.
This section provides the following information:
• Important Safety Instructions
• About the MPA 152 Plus
• MPA 152 Plus Features
Important Safety Instructions
1. Read these instructions.
2. Keep these instructions.
3. Heed all warnings.
4. Follow all instructions.
5. Do not use this apparatus near water.
6. Clean only with dry cloth.
7. Do not block any ventilation openings. Install in accordance with the instructions of the
manufacturer.
8. Do not install near any heat sources such as radiators, heat registers, stoves, or other
apparatus (including amplifiers) that produce heat.
9. 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 are provided
for safety. If the provided plug does not fit into the outlet, consult an electrician for
replacement of the obsolete outlet.
10. Protect the power cord from being walked on or pinched particularly at plugs,
convenience receptacles, and the point where they exit from the apparatus.
11. Only use attachments or accessories specified by the manufacturer.
12.
13. Unplug this apparatus during lightning storms or when unused for long periods of time.
14. Refer all servicing to qualified service personnel. Servicing is required when the
apparatus has been damaged in any way, such as if the power‑supply cord or plug
is damaged, liquid has been spilled or objects have fallen into the apparatus, the
apparatus has been exposed to rain or moisture, does not operate normally, or has
been dropped.
Use only with the cart, stand, tripod, bracket, or table specified by the
manufacturer, or sold with the apparatus. When a cart is used, use caution
when moving the cart/apparatus combination to avoid injury from tip‑over.
MPA 152 Plus • Introduction1
About the MPA 152 Plus
Speakers
The MPA 152 Plus is an ENERGY STAR qualified amplifier with an Extron exclusive, highly
efficient, advanced Class D amplifier design. It also features patented CDRS (Class D
Ripple Suppression) technology that provides a smooth, clean audio waveform and an
improvement in signal fidelity over conventional Class D amplifiers. The high efficiency
design generates very little heat and allows the amplifier to be fanless and operated in
environments with little or no ventilation.
This stereo integrated mini power amplifier delivers up to 15watts(rms) per channel stereo
or dual mono into a 4 ohm sound system, or 8watts(rms)per channel into an 8ohm
system. This model features a 90 dB signal‑to‑noise ratio with 0.1% THD+N, offering
exceptional performance for speaker systems requiring compact, economical, audio
amplification.
Front panel controls allow easy adjustment of bass and treble volume and input level.
The quarter rack size allows a variety of mounting options. The unit complies with UL 2043
for smoke and heat release for in‑the‑ceiling installations. It can be installed in the plenum
space of the ceiling. Alternatively, the units can be mounted on a tabletop, in a rack, under a
desk, or in a projector mounting kit.
MPA 152 Plus Features
1
EO
VID
2
X
DISPLAY
AU
FF
EO
O
VID
3
ON
PC
4
VOLUME
IMAGE
ONFIG
TE
C
MU
MLC 104 IP PLUS
Extron
Extron
MLC 104 IP Plus
MediaLink Controller
with IP Link
Laptop
INPUTS
MPA 152 Plus
R
POWER
12V
0.7A MAX
L
Extron
MPA 152 Plus
Mini Power
Amplier
Projector
RS-232 or
IR Projector
control
Audio
OUTPUT REMOTE
Ω
R
4
/
Ω
8
L
CLASS 2
WIRING
50mA
VC G
10V
R
L
Audio
Audio
Extron
SM 3
Full-range
Audio
S-Video
RGBHV
Video
DVD/VCR
Combo
Figure 1. Typical Application for the MPA 152 Plus
30 watts (rms) output power — Delivers up to 15watts(rms) per channel, stereo or
dual mono, into a 4 ohm speaker system or up to 8watts(rms) per channel into an 8ohm
system. Provides significant audio output for small integration projects with moderate sound
system needs.
Improved signal-to-noise ratio — The 90 dB unweighted signal‑to‑noise ratio allows
very low‑noise operation, ensures quiet, hiss‑free amplification, and maintains audio signal
integrity.
ENERGY STAR qualified amplifier — The MPA 152 Plus conserves energy and reduces
operating costs.
MPA 152 Plus • Introduction2
Defeatable auto power-down timer for 24/7 applications — Ensures that the
amplifier is always active for 24/7 operation in critical applications, while still retaining the
ENERGYSTAR qualification.
Extron patented CDRS - Class D Ripple Suppression — CDRS is an Extron patented
technology that provides a smooth, clean audio waveform and an improvement in signal
fidelity over conventional Class D amplifier designs. CDRS eliminates the high frequency
switching ripple characteristic of Class D amplifiers, a source of RF emissions which can
interfere with sensitive AV equipment such as wireless microphones.
Front panel bass, treble, and input level controls — These are flush mounted and
detented. They allow quick attenuation of input signal and ±10 dB bass and treble shelving
controls.
Stereo or Dual Mono toggle switch — Allows the user to choose between stereo output
or to sum the left and right inputs and produce dual mono outputs (see figure7 on page9).
This eliminates the need for external summing products in monoaural installations.
UL 2043 plenum rated — The MPA 152 Plus complies with UL 2043 for smoke and
heat release for installation within a plenum airspace above a drop ceiling (power supply
excluded). Above‑the‑ceiling placement conceals the amplifier to prevent theft, and is
convenient for installing equipment when space inside the room is limited.
Three audio inputs — Accept balanced or unbalanced stereo line‑level signals on a
captive screw connector and unbalanced stereo line‑level signals on an RCA stereo pair,
and a 3.5 mm stereo mini jack. This ensures the amplifier can be easily integrated with a
wide variety of sources and projectors.
The three stereo inputs are individually buffered and can be connected to three separate
sources at the same time without altering performance.
Auto power-down with fast power-up — The MPA 152 Plus meets ENERGY STAR
qualification requirements with an auto power‑down feature that automatically places
the amplifier into standby after 25 minutes of inactivity, dramatically reducing power
consumption. It quickly returns to full power status in less than one second upon signal
detection. This feature can be defeated to allow for 24/7 operation.
Quick-plug speaker outputs — Speaker output is on a screw‑lock captive screw
connector for quick installation.
Volume and mute remote control — A rear panel, three‑pin captive screw remote input
connector allows remote adjustment of volume and muting.
Always-on clip limiting — Reduces gain automatically to prevent amplifier clipping.
Compact size — The amplifiers are housed in a 1U high, 3 inch deep, quarter rack wide
metal enclosure, which offers flexible mounting options.
MPA 152 Plus • Introduction3
Panels and
Cabling
This section discusses the MPA 152 Plus rear panel features and cabling.
MPA 152 Plus Rear Panel Features
The rear panel of the MPA 152 Plus (shown in figure 2 below) allows the user to connect
power (see below), audio input (see page 6), remote control (see page7), and audio
output (see page9).
MPA 152 Plus
0.7A MAX
Figure 2. MPA 152 Plus Rear Panel Features
Power Connector
Power connector — The MPA 152 Plus ships with the Extron 24 watt PS 1220
a
desktop power supply.
ATTENTION: When the PS 1220 power supply is connected to the
Connect one end of the DC power cord to one of the two pole, 3.5 mm captive screw
outlets on the power supply. Connect the other end into the power receptacle on the
rear panel of the amplifier, as shown in figure 3 on the following page. The power cord
connectors are correctly wired when shipped.
OUTPUTREMOTE
/
4Ω8
Ω
CLASS 2
INPUTS
POWER
12V
L
123456
R
WIRING
L
R
L
R
VCG
10V50mA
MPA152Plus, it must not be shared with any other devices.
MPA 152 Plus • Panels and Cabling4
MP
ew
PS 1220
A 152 Plus
Amplier
POWER
12V
0.7A MAX
DC Power Cord
Captive Screw
Connector
Power
Receptacle
Power Supply
Output Cord
Power Supply
AC Power Cord
DO NOT USE
DC Power
Outputs
Captive Scr
Connector
Wrap
Tie
Figure 3. Power Connector
ATTENTION:
• Always use a power supply supplied by or specified by Extron. Use of an
unauthorized power supply voids all regulatory compliance certification and
may cause damage to the supply and the end product.
• The amplifier is suitable for use in environmental air space in accordance
with Section300.22.C of the National Electrical Code, and Sections 2‑128,
12‑010(3) and 12‑100 of the Canadian Electrical Code, Part 1, C22.1.
• Unless otherwise stated, the AC/DC adapters are not suitable for use in air
handling spaces or in wall cavities. The power supply is to be located within
the same vicinity as the Extron AV processing equipment in an ordinary
location, Pollution Degree 2, secured to the equipment rack within the
dedicated closet, podium, or desk.
• Although the amplifier is plenum rated, the power supply provided with it
is not. The power supply must not be placed in the plenum space. Cables
to and from the amplifier must also be plenum rated. The DC power cord
provided with the unit is not plenum rated.
• The installation shall be in accordance with the applicable provisions of
National Electrical Code ANSI/NFPA 70, article 725 and the Canadian
Electrical Code part1, section 16.
• The power supply shall not be permanently fixed to building structure or
similar structure.
• The length of the exposed wires in the stripping process is critical. The ideal
length is 3/16 inches (5 mm). Any longer and the exposed wires may touch,
causing a short circuit between them. Any shorter and the wires can be easily
pulled out even if tightly fastened by the captive screws.
NOTE: Do not tin the wires. Tinned wire does not hold its shape and can become
loose over time.
MPA 152 Plus • Panels and Cabling5
Audio Inputs
Tip (+)
RCA Connector
Tip (L)
3.5 mm TRS Connector
LR
Slee
Slee
Balanced Mono Input
LR
Unbalanced Mono Input
Slee
Use the rear panel receptacles (see figure 4) to connect audio sources to the amplifier. Wire
the connectors as shown below.
INPUTS
R
L
R
L
243
Figure 4. Audio Inputs
RCA unbalanced stereo input connectors — These
b
receptacles accept unbalanced, line level audio signals. The input
can be stereo, using two RCA connectors, or mono, using a
single RCAconnector plugged into the left receptacle.
Sleeve ( )
If unused, the receptacles automatically terminate to lower the
noise floor.
3.5 mm unbalanced stereo input jack — This input also
c
Ring (R)
accepts unbalanced, line level audio signals through a 3.5 mm
tip‑ring‑sleeve (TRS) stereo connector. If unused, the receptacle
automatically terminates to lower the noise floor.
Sleeve ( )
Captive screw balanced
d
or unbalanced audio input
connector — This 5‑pole 3.5 mm
Tip
Tip
LR
ve
ve
Tip
Ring
Sleeves
Tip
Ring
captive screw receptacle accepts line
level, balanced or unbalanced, mono
or stereo audio signals.
See the attention (on page 5) and
note (on page5) for important
Unbalanced Stereo Input
Tip
ve
LR
information about connecting wires to
Balanced Stereo Input
Tip
Ring
Sleeve
captive screw connectors.
Depending on the position of the
front panel toggle switch (see figure8 on page 10), the right and left channels may be
output as a stereo signal or as a dual mono signal. See Audio Output on page 9 for
more information.
MPA 152 Plus • Panels and Cabling6
Remote Control
Ground (Pin 3)
V
10k ohm
REMOTE
Remote input connector — This 3‑pin, captive screw port allows
e
Wiring for remote control
Options for remote control include the Extron VC50, VCM100AAP, VCM100MAAP,
VCM200 series, and MLAVC10 Plus. Third party 10k potentiometer volume controllers can
also be connected to this port.
Figure 5 and the instructions below show the wiring for the VCM 100 MAAP. Wiring other
remote control connectors is similar.
an audio controller to control volume and mute levels remotely. See
Remote Control Options on page 11 if using a MediaLink controller.
REMOTE
VCG
10 V (Pin 1)
10V50mA
VCG
10V50mA
olume Pot
s
2k ohms
Mute
Switch
Vol/Mute
(Pin 2)
Figure 5. Remote Control Wiring
• Pin 1 is for 10 VDC reference voltage output.
• Pin 2 (C) has two functions:
• Volume control: it can be used as a variable voltage input between 0 and 10 VDC,
with 0 V giving full attenuation and 10 V giving maximum volume.
• Mute: it can be used for remote control muting. Sound is muted while this pin is
shorted to ground.
• Pin 3 is for the ground connection.
NOTE: All nominal levels are at ±10%.
Controlling multiple amplifiers with one volume controller
Several MPA 152 Plus units can be daisy‑chained so that one volume controller can
simultaneously regulate the volume of all the amplifiers.
NOTES:
• As additional amplifiers are added to the daisy chain, the sensitivity of the
volume potentiometer changes. The maximum volume level (fully clockwise)
is not affected. However the effectiveness of the minimum volume level (fully
counterclockwise) in reducing the volume to inaudible levels decreases as
more amplifiers are added to the daisy chain.
• When more than two amplifiers are attached to the chain, sound may begin
to be heard even if the levels have been set to their lowest. The muting of
the output however can be remedied with a contact closure button attached
between the C (volume or mute) and G (ground) pins of the first amplifier in the
chain.
MPA 152 Plus • Panels and Cabling7
To regulate multiple amplifiers with a single volume controller, follow these instructions:
10V50m
A
10V50mA
10V50mA
VOL/MUTE
Ext
MP
Daisy Chain
1. Attach all three pins of the volume controller to the corresponding pins on the first
MPA152Plus unit only:
• Ground ( ) to ground (G)
• Vol/Mute to C
• 10 V to V.
2. Use jumper wires to connect the C (Volume and Mute) pins of the first amplifier and
each successive amplifier.
3. Use jumper wires to connect the ground pins of the first amplifier and each successive
amplifier.
Extron
10V
VCM 100 AAP
ron
A 152 Plus
VCG
VCG
VCG
Figure 6. Regulating Multiple Amplifiers with a Single Volume Controller
NOTE: The 10V pin of the volume controller connects to the first MPA 152 Plus
only. There are no jumper wires linking it to subsequent amplifiers.
MPA 152 Plus • Panels and Cabling8
Audio Output
Captive
-
Stereo/Dual Mono Switch
OUTPUT
Speaker receptacle — This 4‑pole, 5 mm screw lock
f
captive screw receptacle is used to connect the amplifier
to the speakers.
With an 8 ohm load, the amplifier produces up to 8watts
per channel. With a 4 ohm load, the amplifier produces up
/
4Ω8
Ω
CLASS 2
WIRING
L
to 15watts per channel.
See the attention (page 5) and note (page 5) for important information about
connecting wires to captive screw connectors.
ATTENTION: Do not short the + and – outputs to each other, as this will damage
the amplifier.
R
Left
Right
Screw
RCA
TRS
Captive
Screw
RCA
TRS
+
+
+
+
+
+
+
+
+
+
Stereo
+
Dual
Mono
+
Stereo
Amp Stage
Figure 7. MPA 152 Plus Summing Diagram
Signal flow is as follows:
1. The MPA 152 Plus sums and weights the left unbalanced signals from the TRS and
RCA receptacles. This summed, unbalanced signal is then summed with the left
balanced signal from the captive screw receptacle.
2. The right channel is handled in the same way.
3. The left and right channels are then sent to the output amplifiers in one of two ways,
depending on how the front panel switch is set.
• Stereo: The left and right channels are sent to the left and right output amplifers
respectively.
• Dual Mono: The left and right channels are summed and then the resulting mono is
fed to both of the output amplifiers.
The captive screw, RCA, and TRS inputs are buffered.
MPA 152 Plus • Panels and Cabling9
Setup and
Operation
This section discusses:
• Front Panel Features and Operation
• Remote Control Options
• Defeating the Auto Power-down Timer
• Troubleshooting
Front Panel Features and Operation
This section describes how configure the MPA 152 Plus, using the front panel controls and
how to set up the remote control options.
1
Figure 8. MPA 152 Plus Front Panel
Power LED — The LED lights green when the MPA 152 Plus unit is receiving power
a
and active. It lights amber when the unit is powered down (after 25 minutes of inactivity).
Stereo or Dual Mono toggle switch — Allows the user to choose between stereo
b
output for stereo applications (default) or dual mono output for mono applications.
Level, Bass, and Treble potentiometers — Three front panel potentiometers are
c
used to optimize input level, bass, and treble settings.
Setting Input Level
Adjust the MPA 152 Plus input level as follows:
1. Unplug the Remote plug from the unit.
2. Set the volume of the audio source to its minimum level.
3. Turn the Level potentiometer fully counterclockwise to its minimum setting.
4. Set the volume of the audio source to its maximum level. No sound should come out.
5. Slowly increase the MPA 152 Plus level by rotating the Level potentiometer clockwise
until sound distortion starts. Lower the level slightly until the distortion disappears. At
this setting, whatever the volume setting of the audio source, no clipping will occur.
STEREO
DUAL
MONO
2
BASSLEVELTREBLE
MPA 152 Plus
MINI POWER AMPLIFIER
3
MPA 152 Plus • Setup and Operation10
Setting Bass and Treble
oller
Adjust the MPA 152 Plus bass and treble as follows:
1. Use the Bass potentiometer to increase or decrease the bass shelving ±10 dB at 80 Hz
2. Use the Treble potentiometer to increase or decrease the treble shelving ±10 dB at
Remote Control Options
and below.
10kHz and above.
NOTE: Turning the Bass or Treble potentiometers counterclockwise will decrease the
output at the specified frequencies. Turning the potentiometers clockwise will increase
the output. When the potentiometer is in the center, flat response is achieved.
8 ohm Ceiling
Speakers
in Parallel
MUTE
VOLUME
VCM 100 AAP
2
Extron
VCM 100 AAP
Volume/Mute Contr
VCR
Composite
Audio RCA
PROJECTOR
OFF
ON
VOLUME
Extron
3
MLC 104 IP
Controller
DVD
S-video
Audio RCA
1
2
3
4
CONFIG
MLC 104 IP
ComLink
PC
VGA w/
Audio Cable
INPUTS
MPA 152 Plus
R
POWER
12V
0.7A MAX
L
Variable
Audio
Output
Projector
4
/
Ω
8
CLASS 2
WIRING
L
OUTPUT REMOTE
Ω
R
L
V C G
10V 50mA
R
Extron
MPA 152 Plus
Mini Power Amplifier
1
IR Remote
Figure 9. Typical Application for the MPA 152 Plus, Using Remote Control
Using the IR remote for the projector — When using a projector with variable audio
a
outputs, connect the projector audio output to the MPA 152 Plus audio input. Use
the IR remote for the projector to control the volume of the projector, which effectively
controls the volume of the MPA 152 Plus.
Extron volume controllers — Extron provides a range of volume and mute controllers
b
for use with a projector that lacks variable audio outputs. These options control the
MPA 152 Plus volume directly (see Wiring for remote control on page 7).
Using a MediaLink Controller — For a projector with variable audio output, connect
c
the projector audio output to the MPA 152 Plus audio input. Use a MediaLink controller
to adjust the volume of the projector via RS‑232. MediaLink controllers can also use the
IR remote to adjust the volume of the projector and, thus, the input to the amplifier.
MPA 152 Plus • Setup and Operation11
Defeating the Auto Power-down Timer
secure the top enclosure to the bottom.
The auto power‑down timer determines whether or not the amplifier enters standby mode.
The amplifier powers down if the input signal remains below the input signal detection
threshold for about 25 minutes.
The timer resets whenever the input signal exceeds the input signal detection threshold.
Resetting the timer starts a new 25 minute countdown until the amplifier powers down.
Resetting the timer also causes an amplifier that is already powered down to “wake up.”
There may be times when it is desirable to bypass the auto power‑down timer. However,
this should be done as a last resort. Examples of when defeating the auto power‑down
circuit might be required include:
• If the amplifier is used in a paging system. When the amplifier has already powered
down, the first syllable might be cut off as the amplifier wakes up from standby mode.
• If the input signal is so quiet that the level remains below the input signal detection
threshold for 25minutes, the timer would cut the audio in the middle of playback by
placing the amplifier into standby mode.
ATTENTION: The following procedure cannot be reversed and should be carried out
as a last resort. Be certain that you need to defeat the auto power‑down timer before
continuing.
To defeat the auto power‑down timer, follow these
instructions:
1. Disconnect power from the amplifier.
2. Remove the four screws that secure the top
enclosure to the bottom enclosure (there are two
screws on each side panel).
ATTENTION: Exercise caution when removing
the screws to avoid stripping the head.
3. Slide the top enclosure forward to clear the switch
and potentiometers on the front panel, then lift it
straight up to separate it from the bottom enclosure.
The circuit boards are now exposed at the front.
INPUTS
MPA 152 Plus
R
POWER
12V
0.7A MAX
L
Four screws (two on each side)
OUTPUT REMOTE
Ω
R
4
/
Ω
8
L
CLASS 2
WIRING
V C G
10V 50mA
R
L
ATTENTION: Do not touch the electronic components or circuit board connectors
without being electrically grounded. Handle circuit boards by their edges only.
ESD can damage circuits, even if you cannot feel, see, or hear it.
MPA 152 Plus • Setup and Operation12
Resistor R42
Troubleshooting
Amplifier Fails to Exit Standby Mode Promptly
Stereo to Dual Mono
Toggle Switch
Level Potentiometer
Figure 10. Front View, Showing the Location of Resistor R42
4. Identify resistor R42 at the front of the bottom circuit board between the Stereo to Dual
Mono toggle switch (to the left) and the Level potentiometer (to the right). The resistor is
shown in the white box in figure 10.
5. Remove the resistor using a pair of diagonal cutters to clip the wires attaching it to the
circuit board.
6. Re‑attach the top enclosure with the four screws removed in step 1.
Under different circumstances, the front panel LED lights green or amber to provide
diagnostic information.
Power LED
Problem DescriptionProblem Solution
Color
AmberNo output signal.No input detected: verify that there is an
GreenNo output signal.The amplifier may be in mute mode. Check
Green or
Amber
Slow to exit standby mode
when a signal is present.
Amplifier Enters Standby Mode Too Early
Power LED
Color
Green or
Amber
Problem DescriptionProblem Solution
Enters standby mode
early.
input signal.
If a signal is present, raise the level of the
source signal.
the Remote port.
The input signal may be too weak. Raise the
level of the source signal.
The input signal may be too weak. Raise the
level of the source signal.
MPA 152 Plus • Setup and Operation13
Mounting
This section provides information about the mounting options for the MPA 152 Plus.
Rack Mounting
UL Guidelines for Rack Mounting
The following Underwriters Laboratories (UL) guidelines are relevant to the safe
installation of this product in a rack:
1. Elevated operating ambient temperature — If the unit is installed in a closed
2. Reduced air flow — Install the equipment in the rack so that the equipment gets
3. Mechanical loading — Mount the equipment in the rack so that uneven
4. Circuit overloading — Connect the equipment to the supply circuit and consider
5. Reliable earthing (grounding) — Maintain reliable grounding of rack‑mounted
or multi‑unit rack assembly, the operating ambient temperature of the rack
environment may be greater than room ambient temperature. Therefore, install the
equipment in an environment compatible with the maximum ambient temperature
(TMA: +122 °F, +50°C) specified by Extron.
adequate air flow for safe operation.
mechanical loading does not create a hazardous condition.
the effect that circuit overloading might have on overcurrent protection and supply
wiring. Appropriate consideration of the equipment nameplate ratings should be
used when addressing this concern.
equipment. Pay particular attention to supply connections other than direct
connections to the branch circuit (such as the use of power strips).
MPA 152 Plus • Mounting14
Rack Mounting Procedure
3.67"
The unit can be mounted on a compatible rack system (optional). Follow the instructions
provided with the shelf accessories.
ATTENTION: Use only the two holes indicated in the diagram below for mounting
the MPA152Plus. The other four holes anchor stand‑offs for the internal circuit
boards; using them may damage the amplifier and will not provide secure
mounting for the unit.
1.44"
Hole for Rack
Mounting Screw
(#4-40 Thread)
Hole for Rack
Mounting Screw
(#4-40 Thread)
Back of the Rack Mounting
Mount the unit at the back of a rack rail, following the instructions provided with the kit.
Other Mounting Options
• Tabletop placement — Place the unit in any convenient location.
• Plenum placement — The MPA 152 Plus amplifier complies with Section 300.22 (c) of
• Under-desk mounting — Mount the unit under a desk or podium, following the
• Pole mounting — Mount the unit above a projector using a Pole Mounting Kit. Follow
• ZipClip 200 mounting — Mount the unit under furniture or to a rack rail using the
Figure 11. Base of MPA 152 Plus to Show Mounting Holes
the National Electrical Code and is suitable for use in an Environmental Air Space. It can
be installed in the ceiling, out of sight, with reduced risk of theft.
ATTENTION: Although the amplifier is plenum rated, the power supply provided
with it is not. The power supply must not be placed in the plenum space. Cables
to and from the amplifier must also be plenum rated. The DC power cord
provided with the unit is not plenum rated.
instructions provided with the kit.
the instructions provided with the kit.
ZipClip 200. Follow the instructions provided with the mounting kit.
MPA 152 Plus • Mounting15
Extron Warranty
Extron Electronics warrants this product against defects in materials and workmanship for a period of three years
from the date of purchase. In the event of malfunction during the warranty period attributable directly to faulty
workmanship and/or materials, Extron Electronics will, at its option, repair or replace said products or components,
to whatever extent it shall deem necessary to restore said product to proper operating condition, provided that it is
returned within the warranty period, with proof of purchase and description of malfunction to:
USA, Canada, South America,
and Central America:
Extron Electronics
1230 South Lewis Street
Anaheim, CA 92805
U.S.A.
Europe and Africa:
Extron Europe
Hanzeboulevard 10
3825 PH Amersfoort
The Netherlands
Japan:
Extron Electronics, Japan
Kyodo Building, 16 Ichibancho
Chiyoda-ku, Tokyo 102-0082
Japan
China:
Extron China
686 Ronghua Road
Songjiang District
Shanghai 201611
China
Asia:
Extron Electronics Asia Pte. Ltd.
135 Joo Seng Road, #04-01
PM Industrial Bldg.
Singapore 368363
Middle East:
Extron Middle East
Dubai Airport Free Zone
F12, PO Box 293666
United Arab Emirates, Dubai
Singapore
This Limited Warranty does not apply if the fault has been caused by misuse, improper handling care, electrical
or mechanical abuse, abnormal operating conditions, or if modifications were made to the product that were not
authorized by Extron.
NOTE: If a product is defective, please call Extron and ask for an Application Engineer to receive an RA (Return
Authorization) number. This will begin the repair process.
USA: 714.491.1500 or 800.633.9876 Europe: 31.33.453.4040
Asia: 65.6383.4400 Japan: 81.3.3511.7655
Units must be returned insured, with shipping charges prepaid. If not insured, you assume the risk of loss or damage
during shipment. Returned units must include the serial number and a description of the problem, as well as the
name of the person to contact in case there are any questions.
Extron Electronics makes no further warranties either expressed or implied with respect to the product and its quality,
performance, merchantability, or fitness for any particular use. In no event will Extron Electronics be liable for direct,
indirect, or consequential damages resulting from any defect in this product even if Extron Electronics has been
advised of such damage.
Please note that laws vary from state to state and country to country, and that some provisions of this warranty may
not apply to you.
Extron Headquarters
+1.800.633.9876 (Inside USA/Canada Only)
Extron USA - West Extron USA - East
+1.714.491.1500 +1.919.850.1000
+1.714.491.1517 FAX +1.919.850.1001 FAX