APART MA247 series User manual

MA247 series
Instruction manual

Instruction manualMA247 series
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MA247 series

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MIXING AMPLIFIERS
Safety First !
• Caution: hot and sharp surfaces! This professional device needs
to be installed by qualified personnel only.
• Please check the packing for any kind of damage upon
reception of the goods. If the packing is damaged, please
contact your dealer before opening it.
• !!!! Danger!!!! Exposure to high sound pressure levels may
cause permanent hearing loss. Hearing loss induced by
exposure to high sound pressure levels will vary from individual
to individual, but nearly everyone will lose some hearing
when exposed for a sufficient amount of time. Therefore it is
recommended that all persons exposed to equipment capable
of producing high sound pressure levels, such as this amplifier,
wear sufficient ear protection while installing or operating this
unit.
• Read all documentation before operating your equipment.
• Keep all documentation for future reference.
• Keep the carton and packing material, even if the equipment
has arrived in good condition.
• Should you ever need to send the unit back, use only the
original factory packing.
• Do not spill water or other liquids on or into the unit.
• Make sure power outlets conform to the power requirements
listed on the back of the unit.
• Do not use the unit if the electrical power cord is damaged.
• Always operate the unit with the AC ground wire connected to
the electrical system ground.

Instruction manualMA247 series
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• Turn the level controls on the amplifiers all the way down
during power-up to prevent speaker damage if there are high
signal levels at the inputs.
• Do not connect the inputs / outputs of amplifiers or consoles
to any other Voltage source, such as batteries, mains sources or
power supplies, regardless of whether the amplifier or console
is turned ON or OFF.
• Power down and disconnect units from mains Voltage before
making connections.
• Do not use the unit near stoves, heat registers, radiators, or
other heat producing devices.
• Do not operate equipment on a surface or in an environment
which may distort the normal flow of air around the unit. If the
unit is used in an extremely dusty or smoky environment, the
unit should regularly be “blown free” of dust.
• Do not remove the cover. Removing the cover will expose you
to potentially dangerous Volt-ages.
• Do not drive the inputs with a signal level higher than that
which is required to drive equipment to full output.
• Do not run the output of any amplifier back into another input.
• In case of malfunction, this device should be serviced by
qualified service personnel only.

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MIXING AMPLIFIERS
Features
The MA247 sets a new standard as a professional 6 zone PA
mixing amplifier/preamplifier for commercial and industrial
applications, either as a standalone unit or as the central device in
an expandable, simple but clever paging system. The amplifier is
equipped with 4 balanced mic/line inputs, each with adjustable gain
and tone controls, up to 4 line level inputs and an emergency input.
The MA247 has a six level priority system. The emergency/
telephone input has the highest priority and is activated by a
switch or vox circuitry. Its signal goes directly to the main amplifier,
bypassing any level control accessible at the front of the unit. An
attenuator next to the input sets its level. Micro¬phone input 1 has
the second priority level, followed by the mic 2, 3 and 4 and finally
the line signals (music).
Zones 2 to 6 can be volume controlled individually. Please note
that zones number 5 and 6 are 70 Volt outputs, these are
compatible with 100 Volt speakers, but by nature, these outputs
will have a slightly reduced output level, meant for the ‘quiet’
zones in a multizone system. For even more flexibility, zone 1 is an
independent zone with a separate line level output, which turns
the MA247 into a true 2 zone mixing amplifier with integrated
preamplifier. During paging, the corresponding integrated volume
control will be automatically bypassed. When priority has been
activated in any zone, the internal 24VDC supply output (max
0.6A) can activate priority relays of loudspeaker attenuators or
other devices. There is a dedicated 24V output per zone! Even an
emergency 24 VDC supply input is present on the unit. The supply
will automatically keep the amplifier powered when mains power is
interrupted. Mic input 1 is optimized to be used with our MICPAT-6,
a selective paging station 6 zone microphone.
This mic is the master mic. Maximum 5 of these mics can

Instruction manualMA247 series
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be switched in parallel on this single input! Mic input 2 - 4
are designed to be used with our MICPAT-2 (2 zone groups)
microphone or any other microphone depending on the application.
On the MA247 unit you can preset 2 paging groups to be paged
with mic 2 – 4. Please note that it is not possible to connect
multiple MICPAT-2 mics
to the same input.
That’s not all. If you are a professional installer, you will appreciate
the possibility to use an external amplifier as paging amplifier.
Why? Suppose zones 2 and 3 should not receive paging messages,
meaning there should always be background music. Then you can
use an external amplifier for all paging tasks. MA247 does all the
switching and thinking for you. The internal amplifier will be used
for background music. When a paging message is sent to other
zones than zone 2 and 3, zone 2 and 3 will stay connected to the
internal amplifier and will continue to play the music. All other
zones will hear the paging message: the MA247 will disconnect
these zones from the internal amplifier and will send the paging
signal to the external amplifier. The external amplifier will feed
the signal to the selected zones via the MA247. When paging
is finished, the zones will automatically be switched back to the
internal amplifier. We will show an example of such application in
this manual. We will use a 2 channel PA2240BP amplifier and a
MA247 in an application that would normally use at least twice as
much units to do all the switching and signal routing.
A unique new switching circuit design has been applied to ensure
trouble-free switching for many years.
Removable 19” brackets are delivered as a standard accessory along
with your amplifier.
The MA247 complies with the CE standards.

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MIXING AMPLIFIERS
Operation
Front panel MA247
1. Zone 1 output level: this level control sets the output level to
the zone 1 preamp output.
2. Zone 1 paging LED: this LED lights up when zone 1 is being
paged.
3. Zone 1 music selector: selects the line level input for zone 1.
4. Zone 2 paging LED: this LED lights up when zone 2 is being
paged.
5. Zone 2 level control: this control is used to preset the zone 2
level relative to the master level.
6. Zone 3 paging LED: this LED lights up when zone 3 is being
paged.
7. Zone 3 level control: this control is used to preset the zone 3
level relative to the master level.
1
2 4 6 8 10
11
12
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2423222120
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8. Zone 4 paging LED: this LED lights up when zone 4 is being
paged.
9. Zone 4 level control: this control is used to preset the zone 4
level relative to the master level.
10. Zone 5 paging LED: this LED lights up when zone 5 is being
paged.
11. Zone 5 level control: this control is used to preset the zone 5
level relative to the master level.
12. Zone 6 paging LED: this LED lights up when zone 6 is being
paged.
13. Zone 6 level control: this control is used to preset the zone 6
level relative to the master level.
14. Level indicators/clip-limit: The protect LED lights up for a few
seconds during start-up, or when an error occurs, such as
overheating or overload. The lower green on LED will light up
to indicate that power is present. The signal LED indicates that
a strong signal is sent to the power amplifier. To work within
normal conditions, the vol¬ume indicator should be kept under
0dB (100%). At -2,5dB a
limiter will be activated. This red LED indicates that the “auto
gain circuit” keeps the level below clipping. This is NOT a clip
indicator, but an indication of the “automatic gain control”. Set
your max levels so that the limiter LED never lights up!
15. Zone 2 – 6 music selector: selects the line level input for zones
2 - 6.
16. Music bass tone control.
17. Music treble tone control.

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18. Music level control: turn this level knob to adjust the music level
relative to the microphone signals.
19. Music muted by priority LED: this red LED lights up when the
music is muted by any priority signal or priority contact. When
this LED lights up, there are 24 VDC outputs available on the
rear connector. 1 output for every zone, capable of supplying
0.3A per zone with a maximum of 0.6A for all zones together.
20. Mic/Line 2 level control: turn this knob to adjust the mic/line 2
level relative to other signals.
21. Mic/Line 3 level control: turn this knob to adjust the mic/line 3
level relative to other signals.
22. Mic/Line 4 level control: turn this knob to adjust the mic/line 4
level relative to other signals.
23. Master level control: turn this knob to set the global mix level in
zones 2 – 6. This control will be bypassed when the emergency
input is activated.
24. Power switch: switch mains power on and off. This switch
turns off the amplifier when connected to the mains AC supply.
Please note that this switch does not switch the amplifier off
when operating from a 24 VDC emergency power supply.

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Important information
• Zone 2 - 6 level controls are used to preset levels in different
zones relative to the master level and to switch off certain
zones temporarily. Zone 5 and 6 outputs are 70 Volt outputs,
these are fully compatible with 100 Volt speakers but will
produce a maximum output level about 3 dB lower than
normal 100 Volt lines. Use these outputs in the most silent
zones. When using an external paging amplifier, all speaker
outputs from the selected zones are switched to maximum
volume (100 Volt) during paging. In other words: the zone
volume controls from zone 2-6 are bypassed during paging.
• A maximum of 180 Watts speaker load is allowed per zone,
with a total maximum of 240 Watts for all zones when using
the internal MA247 power amplifier only. Do not overload
the amplifier. If the amplifier is overloaded, it will result in
overheating. Check your total speaker load with an impedance
or Wattmeter before operating the amplifier. Minimum total
speaker impedance (all zones combined) is calculated like
this (100 V x 100 V) / 240 W = 41.66 Ohms. Please note that
impedance can NOT be measured with a normal multimeter,
you need a special impedance meter or 100 Volt line
Wattmeter for this purpose. If you need more speakers and/or
more power, then you should use an external power amplifier.
The MA247 has an independent preamplifier circuit for zone 1,
and a combined pre-out/amp-in connector for all other zones,
allowing you to increase the total output power without the
need of a supplementary preamplifier.
• Please note that in some cases the music level in non-pageable
zones can slightly vary during paging. When you use an
external paging amplifier, the internal power amplifier will
‘see’ fewer speakers at its output, because these speakers are
switched to the external amplifier’s output during paging. This

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MIXING AMPLIFIERS
can result in music levels varying, depending on the speaker
load variation. This is not a malfunction. This effect will increase
depending on the speaker load variation. You can avoid such
situations by powering the sensitive zones with an external
amplifier connected to zone 1 line level output.
Front & Rear panel MA247MR
• Music selector 3 and 15 have 2 aux source inputs + internal
tuner and MP3 player section (MA247 has 4 aux source
inputs).
• On the left side of the front panel you will find a digital tuner
and the MP3 player. Operation of the tuner and MP3 player
will be explained later.
• Difference in MA247MR rear panel layout:
• Aux 3 & 4 mono input (26) have been replaced by a rec out and
tuner output bus.

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Tuner operation
• Antenna connector (17) for AM wire antenna and FM antenna
coax connector.
• Please note that you must use a HF ground isolation
transformer when connecting the FM antenna input to an
active antenna or cable network!
1. Display section: shows various tuner parameters such as
frequency band (FM or AM), selected frequency and preset
number. The tuner has 10 AM and 10 FM preset memory
locations.
2. FM/AM selector: press to switch between FM or AM band.
3. Scan down: press shortly to scroll one step down in the
frequency band (9 kHz AM, 50 or 100 kHz FM). Press for
about a second to search for the next radio station down the
frequency band.
4. Scan up: press shortly to scroll one step up in the frequency
band (9 kHz AM, 50 or 100 kHz FM). Press for about a second
to search for the next radio station up the frequency band.
1 2
87
3
9
4
10 11 12
5 6

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5. Scan button: press to scan all memory locations: the tuner
automatically selects the next memory location every 3 seconds.
After a full scan, the tuner resumes to normal operation. You can
interrupt the scan cycle by pressing the scan button during the
memory scan.
6. Save button: press this button, followed by a numeric button
(1 to 5, 5+) to store a preset in the internal memory. E.g., you want
to store the currently selected station in memory location number
1: press the save button, followed by the numeric 1 button. If you
want to save in locations 6 to 10: press the save button first, then
the +5 button followed by a numeric button 1 to 5 -> preset 6 =
button +5 followed by button 1…
7. Numeric button 1: press to select or save preset 1
8. Numeric button 2: press to select or save preset 2
9. Numeric button 3: press to select or save preset 3
10. Numeric button 4: press to select or save preset 4
11. Numeric button 5: press to select or save preset 5
12. Numeric button +5: press this button first to select or save
preset stations 6 to 10, followed by a numeric button 1 to 5.
Alternatively, during manual frequency scan, you can press this
button to select a half frequency step, e.g. FM steps are 100
kHz by default, press the +5 button to step up 50 kHz in the FM
band.
Note: after powering on the MA247/MA247MR main unit,
the tuner is automatically powered on. The tuner cannot be
powered off separately.

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MP3 operation
1. Display section: shows various parameters such as track
number, folder number (if present), elapsed track time, MP3
mode…
2. Repeat: press this button to alternate between repeat 1 (repeat
one track), repeat folder or repeat all. Repeat mode is shown in
the display.
3. Shuffle: press once to activate the shuffle function. The unit will
play a randomly selected track. To exit shuffle mode, press the
button once again. Shuffle mode is shown in the display.
4. Folder <<: press this button to select the previous folder. This
button has no function when no folders are present on the
media (USB stick or SD/MMC CARD slot).
5. Folder >>: press this button to select the next folder. This
button has no function when no folders are present on the
media (USB stick or SD/MMC CARD slot).
1 234567
10 11 12 13 14 15
98

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MIXING AMPLIFIERS
6. Track <<: press once (shortly) to select the previous track, keep
pushing to search backward in the track currently playing.
7. Track >>: press once (shortly) to select the next track, keep
pushing to search forward in the track currently playing.
8. USB slot: insert your USB memory stick here. Please note that
an external USB hard disk will most likely not work on this slot.
File system recognized is FAT32, maximum memory size is up
to 32 gigabytes. Some USB sticks don’t allow direct memory
access. These will not work on the MA247MR.
9. MMC /SD card slot: push in the card gently, metal contacts first,
pointing down. Push the card in until you hear a click. Push the
card again to eject. File system recognized is FAT32, maximum
memory size is up to 32 gigabytes.
10. Select USB-CARD: press this button to select USB or memory
card operation.
11. Prog button: press this button to enter program mode. Press a
second time to quit program mode, or press STOP to clear all
program steps. Programs are not memorized after powering
on and off. If you enter program mode, PROGRAM is displayed
in the display, the numeric characters show folder number,
track number and program step number. Enter program mode,
select a folder and track and press shuffle to enter the selected
folder/track. The last characters show the program step. Select
another folder/track and press shuffle to confirm the program
step. When you press shuffle twice, the selected track will
be played twice… After programming all steps, press play to
start playing the program. In order to clear the program, press
program or stop to clear the program steps. Programs cannot
be stored or recalled after cycling the power.

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12. Mute button: press once to mute the MP3 player, press again
to unmute.
13. Play /pause: press to start playback, press again to pause
playback.
14. Stop: press to stop playback.
15. Power button: press to power on or off the MP3 player.
The USB and CARD reader will only read MP3 files. ID3 tag and
folder names are not displayed.
For maximum compatibility, avoid media containing other than the
supported file types.
When a medium is inserted while another medium is playing,
playback will be interrupted.
Not all media are compatible with the media player. Media must be
formatted in FAT32 file system only.
All memory locations on the media must be accessible. Hidden
files and folders, autorun executables or other types of software
necessary for accessing the memory will cause malfunction of
the media player, causing dropouts during playback, unexpected
skipping of files or no functionality at all. In such cases, remove the
media and try media from other manufacturers. Files present on
the media with file extensions other than MP3 may cause erratic
behavior of the media player and should always be avoided.
USB hard disks will most likely not work on the media player’s USB
Notes about media compatibility

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MIXING AMPLIFIERS
Rear panel
1 3 5 10 12
2 4 6 7 8 9 11 13 14 15 16 17
18 34 19 21 23 25 27 29 30 31 32 33
20 22 24 26 28
1. Loudspeaker output connector zone 6: zone 6 is a 70 Volt
speaker line output compatible with 100 Volt speaker lines.
Com = speaker ground, 70 V = speaker plus connection. If this
zone is selected for paging, it will become a normal 100 Volt
line. Use this output for your ‘silent’ zones.
2. Loudspeaker output connector zone 5: zone 5 is a 70 Volt
speaker line output compatible with 100 Volt speaker lines.
Com = speaker ground, 70 V = speaker plus connection. If this
zone is selected for paging, it will become a normal 100 Volt
port for many reasons: the file system is not FAT32, the memory
size exceeds the maximum specifications and the USB port’s supply
current is insufficient to power the hard drive.
Due to FAT32 file system limitations, maximum file size is limited to
4 Gb.
Depending on the reading speed of the media, excessive file
fragmentation may cause erratic behavior of the media player.
Usually, reformatting the media and rewriting the files will solve this
problem.

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line. Use this output for your ‘silent’ zones.
3. Loudspeaker output connector zone 4: zone 4 is a 100 Volt
speaker line output compatible with 100 Volt speaker lines.
Com = speaker ground, 100 V = speaker plus connection.
4. Loudspeaker output connector zone 3: zone 3 is a 100 Volt
speaker line output compatible with 100 Volt speaker lines.
Com = speaker ground, 100 V = speaker plus connection.
5. Loudspeaker output connector zone 2: zone 2 is a 100 Volt
speaker line output compatible with 100 Volt speaker lines.
Com = speaker ground, 100 V = speaker plus connection.
6. Zone 1 balanced line level output: this is the line level output
for zone 1. Connect your external amplifier here.
7. Emergency input with priority contact: the emergency input
has highest priority. The emergency level can be set with knob
‘8’ only and bypasses ALL other level controls. The emergency
signal is also present on the preamp out connectors. You can
activate the emergency input by closing a contact between the
GND and prior connections, or alternatively, activate the input
by setting the automatic vox circuitry. Set the internal jumper
marked ‘S3’ to the vox position and set the threshold level with
VR13. The jumper and level adjustment are located inside the
unit on the rear PCB. In order to reach them you will need to
open the unit. For authorized persons only.

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MIXING AMPLIFIERS
8. Emergency input level: this is the only level control on the
emergency input. The emergency signal bypasses all possible
level controls in the MA247 unit.
9. Chime level: turn this knob to set the level of the two tone
chime. The chime is activated by the priority switches from mic/
line 1 – 4. Please note that the emergency input switch or vox
circuitry does not activate the chime.
10. Paging group 1 dipswitches: click the dipswitches to the ON
position for zone 1 to 6 to enable zone 1 to 6 zone group
paging with mic 2-4. Connect the GND and PG1 (paging group)
connector on mic 2, 3 or 4 to the microphone paging switch.
This will enable zone group 1 paging (e.g.using our MICPAT-2
unit). The dipswitch settings are valid for mic 2 – 4 inputs only.
Mic 1 is a higher priority mic and overrides these settings.
11. Paging group 2 dipswitches: click the dipswitches to the ON
position for zone 1 to 6 to enable zone 1 to 6 zone group
paging with mic 2-4. Connect the GND and PG2 (paging group)
LEVEL
ADJUSTMENT
PRIORITY
SWITCH / VOX
SLECTION
JUMPER