APART MA240 User manual

MA120 - MA240
Instruction manual

Instruction manualMA120 - MA240

4
Mixing amplifiers

Instruction manualMA120 - MA240

6
Mixing amplifiers
Introduction
“Setting a new industry standard”
When we, at Apart, look at mixing amplifiers today it seems like the
complete pro audio industry slumbered. Stuck into old habits, the
overall look and feel remains a hassle for both users and installers
worldwide.
Thanks to excessive research and input from our partners, our
R&D department together with a world leading design company
succeeded in redefining the look of the “mixing amplifier” as we
know it today.
The new and revolutionary Apart MA120/240 mixing amplifier
offers the end-user an unseen cutting edge design and ease of use.
The groundbreaking front panel is clear and easy to use without any
unnecessary bells and whistles.
The refreshing rear panel will give every installer an instant
gratification due to the sheer and logic design.
Together with an unprecedented connectivity and immaculate
sound performance this reliable mixing amplifier is the new
standard in the fixed install audio market.

Instruction manualMA120 - MA240
7
Features
• 19” rack unit, 2U high with removable rack ears.
• High power class-D power amplifier module with 100 volt / 70
volt / 4 ohm output connectivity.
• Output power
- MA120: 1 x 120 W @ 70 V / 100 V / 4 ohm.
- MA240: 1 x 240 W @ 70 V / 100 V / 4 ohm.
• High thermal efficiency.
• PREAMP output and REC output.
• Patented front panel designed to give an intuitive user
interface.
• Front control for end-user and back panel for configuration
installer (out of reach of end-user).
• Universal switching mode power supply.
• Auto standby mode (can be switched off) with < 0.5W standby.
• 24 volt DC / 500 mA priority output.
• Dedicated emergency input with vox and mute all switch.
• Paging mic input with contact closure.
• 2 front panel operated mics: mic A with switchable vox.
• 4 line inputs on RCA.
• Signal clip indicators and gain control on all inputs for fast and
easy configuration of the input gain.
• Status leds on the front panel with led VU meter.
• No cooling fan – maintenance free.
• Extended speaker and amplifier protection circuits : over current
protect, over temperature protect, APC clip limiter.
• 4 priority levels for audio routing.
• Isolated emergency input.

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Mixing amplifiers
1
1. Emergency input: connect your balanced 0 dBV line level emergency
input to the euroblock connector. If available, connect the emergency
contact to the “mute all” connection. The contact must be “potential
free”, i.e. a relay or switch contact that does not carry any voltage.
Alternatively, activate the “vox” circuitry by turning the vox control
until you hear an audible “click”. Now turn the vox control up
while playing music until the vox circuit is activated. The vox and
the mute all switch have the same function: they will mute all other
sources, and will wake up the unit from standby (auto standby and
front button standby). The emergency level can be set with the
volume control. If the clip led lights up when the emergency signal
is present, lower the level of the emergency signal at the source to
avoid distortion. Activating the emergency input will also activate the
priority output (11).
2. Paging mic input: connect your paging mic here: the input accepts
microphone level signals on balanced euroblock, line level signals
on balanced euroblock or RCA. Set the mic/line switch accordingly.
Adjust the gain control so that the clip led does not light up when
the signal is at its highest level. Then set the volume control as
desired. When the paging contact is closed, all other sources (except
emergency input) will be muted, and the chime will sound. Set the
chime level as desired. The paging contact will also activate the
priority output (11). To test the chime level, a chime test button is
present.
14
2 3 4 5 6 7 8 9 10
13
11 12
Connections

Instruction manualMA120 - MA240
9
3. MIC A input: connect a microphone here: the euroblock accepts
balanced microphone or line level signals and RCA. Set the mic/line
switch accordingly. Phantom power (48 V) can be applied to the
balanced euroblock by pushing the phantom power switch. The led
beneath the switch will be lit when phantom power is present. Adjust
the gain control so that the clip led does not light up when the signal
is at its highest level. If necessary, activate the vox circuitry by turning
the vox level control until you hear an audible “click”. Now turn the
vox potmeter up until the vox circuit is activated. The MIC A volume
can be set using the front panel potmeter (2). MIC A can be activated
by pressing the MIC A select switch on the front panel (3). The vox
circuit, when activated, will attenuate (30 dB attenuation) all lower
priority sources (Mic B, input 1-4). MIC A has its own lo and hi eq
controls. MIC A input is compatible with the local input panel that
requires phantom voltage.
4. MIC B input: connect a microphone here: the euroblock accepts a
balanced microphone signal and RCA. The led beneath the switch
will be lit when phantom power is present. Adjust the gain potmeter
so that the clip led does not light up when the signal is at its highest
level. The MIC B volume can be set using the front panel potmeter
(9). MIC B can be activated by pressing the MIC B select switch on
the front panel (10). When selected, the MIC B signal will be mixed
together with a signal present on line input 1-4. MIC B has its own lo
and hi eq controls.
5. Input 1: line level input on RCA connectors. Adjust the gain control
so that the clip led does not light up when the signal is at its highest
level.
6. Input 2: line level input on RCA connectors. Adjust the gain control
so that the clip led does not light up when the signal is at its highest
level.
7. Input 3: line level input on RCA connectors. Adjust the gain control
so that the clip led does not light up when the signal is at its highest
level.

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Mixing amplifiers
8. Input 4: line level input on RCA connectors. Adjust the gain control
so that the clip led does not light up when the signal is at its highest
level.
9. Input 1-4 eq: lo and hi controls for line inputs 1-4.
10. Auto standby: set the switch to “enabled” to enable auto standby.
The amplifier will go to auto standby after 10 minutes if no signal is
present current selected inputs.
11. Priority out: this connector will supply 24 VDC, max 500 mA when
priority is activated. Priority will be activated by the emergency switch
or emergency vox, or by the paging contact on the paging mic input.
Typically, 24 volt priority is used to override volume controllers present
on speaker lines.
12. Speaker out: speaker output connector on euroblock. Use the 4
ohm, or the 70 volt or the 100 volt output. Never use more than one
output at the same time.
13. Pre-outs: the preamp output carries the same line level signal that is
being fed to the power amplifier and is taken after the front panel
volume control (6) and the front panel mic level controls (2). The rec
out carries the same signal as the line out, but it is not influenced
by the position of the front volume button and the front mic level
buttons.
14. Main input connector and power switch: connect the mains power
cord here. Switch on the power switch to power up the unit. The
mains fuse is also located here.

Instruction manualMA120 - MA240
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Note: emergency vox or emergency switch and the paging contact will
mute all lower priority input signals. MIC A vox will attenuate all lower
priority input signals by 30 dB. This is also known as “voice over circuit”.
The chime can only be activated by closing the paging contact on the
paging mic.
As long as the chime sounds, the paging message will be muted, even if
the chime level is set to the minimum(off) level.
IMPORTANT!
This amplifier relies on convectional cooling. In normal situations,
overheating will not occur due to the class D amplifier topology. Since
there are no cooling fans in the amplifier, make sure the convectional
cooling system can work properly. The unit can be built in a 19 inch rack
system using the included 19 inch brackets, but the ventilation holes
should never be blocked. Therefore, it is absolutely necessary to allow
at least one free rack space or 44 mm above the amplifier. Make sure
the ambient temperature is between 0 and 40°C. Operating the unit
beyond its normal limits may cause overheating. If necessary, use a forced
ventilation system in your mounting rack when the rack holds multiple
amplifiers.
The mains fuse is located in the mains inlet (14). When the fuse is broken,
replace it with a fuse of the same current and voltage rating:
- MA120: T 2 A L / 250 V.
- MA240: T 3.15 A L / 250 V.
For qualified personnel only!
Before using the amplifier for the first time, check the total impedance of
your speaker lines using an impedance meter: temporarily disconnect the
speaker line from the amplifier and measure the speaker line. Minimum
load impedance @ 100 volt must be 41.7 ohms or more. This value
corresponds to 240 watts @ 100 volt.
Minimum load impedance @ 70 volt must be 20.4 ohms. Do not use more
than 1 speaker output at the same time.

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Mixing amplifiers
1
1. On / Standby button and led: switch the standby ON / OFF with
this button. Please note that the main power switch at the rear
of the unit (14) must be switched on. Read more about standby
below. When the unit is on, the on/standby button led will light
up steadily. When the unit is in standby, the led will fade in /
fade out.
2. MIC A/B volume control: this control determines the output
volume of MIC A/B.
3. MIC A/B on/off switch: use this button to turn MIC A / B on
and off.
4. Name field: here you can attach the name stickers and the
name fields supplied with the unit.
5. Input 1 – 4 selection buttons: by pressing these buttons, you
can toggle between inputs 1 to 4, or switch off the selected
input by pressing the button that is lit. You can only select one
input at a time.
6. Volume control: turn the control button clockwise to increase
the volume, counterclockwise to decrease. The volume control
sets the output volume of the selected input 1 – 4 only.
2 3 4 5 6 7 8
Operation

Instruction manualMA120 - MA240
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7. Status leds: Protect led lights up when an overload of the
amplifier occurs. The amplifier will be muted until the condition
is normal again. Emergency led will light up to indicate that an
emergency message is coming through. The paging led lights
up when the paging contact is closed. Vox MIC A will light up
to indicate that the vox circuit of MIC A is active. The vox circuit
will only be active if MICA is selected (front button 3).
8. Output VU meter leds: this led bar indicates the output level.
Avoid hitting the red zone!
Standby
The auto standby function can be enabled/disabled via a switch (10)
at the rear of the unit. The power/standby control led will slowly
fade in/out to indicate that standby is activated.
Basically, there are 2 standby modes:
• manual standby: activated by pushing the power button on the
front.
• auto standby: activated by the auto standby circuitry.
The unit will go to auto standby after 10 minutes when the
following requirements are fulfilled:
• Auto standby is enabled
• No audio signal is present on the SELECTED INPUT or MIC*
(or when no input is selected)
• No emergency signal is present and the vox is active or the
emergency contact is not closed
• The paging contact is not closed

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Mixing amplifiers
The unit will wake up from manual standby by any of the
following:
• Pressing the standby / power button.
• Activating the emergency input by the emergency vox or the
emergency mute all.
• Cycling the power using the rear power switch
(or a mains power interruption).
• Pushing any front panel button.
The unit will wake up from auto standby by any of the
following:
• Activating the previously selected sound source
(i.e. signal present on the previously selected input**).
• Pushing any front panel button.
• Activating the paging contact.
• Activating the emergency input by the emergency vox or the
emergency switch.
• Cycling the power using the rear power switch (or a mains
power interruption).
*Note: when the audio cable at the selected input is long and noisy,
the unit will not go to auto standby mode.
**The minimum required signal level required to wake up the unit
from auto standby is 2-10 mVrms for line inputs and
0.1 - 0.5 mVrms for microphone signals.

Instruction manualMA120 - MA240
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The 4 ohm and 70 volt connectors are not used. Connect the
common or speaker line ground wire to the COM connector.
Connect the 100 volt line to the 100 volt connector.
The minimum speaker line impedance is 83.3 / 41.7 ohms
(120 / 240W).
Check the impedance with an impedance meter before connecting
the speaker line to the amplifier.
Practical example
Connecting the speakers
Example: 100 volt speaker line.
Connect the speaker line wires
as shown.
Note: never use more than one output at a time ! Do not overload
the speaker output. In 70 and 100 volt speaker lines, the power of
all speakers in the chain must be added. The total power MUST be
lower than or equal to the amplifier’s output power. For example:
on a 240 watt 100 volt amplifier, you can connect 4 x 60 watt
100 volt speakers in parallel: 4 x 60 = 240 watts.
Always measure the speaker line with an impedance meter or
speaker line watt meter

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Mixing amplifiers
Practical example
Connecting and setting up a paging microphone
1. Connect the microphone wire as shown in the picture.
The + - GND is used for the balanced signal of the microphone.
The paging contact closure is indicated in the picture.
mic signal paging
contact
2. Set the mic / line
button to “MIC”.
3. Close the paging
contact.

Instruction manualMA120 - MA240
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4. While speaking in the microphone as loud as possible, turn the
gain control slowly clockwise until the clip led lights up at the
highest peaks. Now turn the control back a little. Open the
volume control until the paging message sounds as loud as
desired. Watch the output VU meter on the front of the unit
and make sure meter never hits the red zone.
5. Open the paging contact.

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Mixing amplifiers
6. Turn the chime potmeter about halfway, push the “test”
button to hear the chime and adjust the chime volume as
desired using the chime potmeter.
Note: the paging mic and chime levels are independent from the
position of the big volume control on the front of the unit.
The paging contacts must be potential free, i.e. no voltages should
be present on these connectors.

Instruction manualMA120 - MA240
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Practical example
Connecting a line source (tuner, CD player, ...) to input 1
1. Connect the output of
the line source to the
cinch connectors of
input.
2. While the line source is
playing, turn the gain
control on input 1 slowly
clockwise until the clip led
lights up at the highest
signal peaks. Now turn the
control back a little.

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Mixing amplifiers
3. Select “INPUT 1” on the front panel. Turn up the big volume
control on the front panel to hear the selected source through
the speaker(s).
Note: use the gain control also to equalize the level differences
between sources. For example, if the CD player plays “louder” than
the radio, turn the gain control of the CD player a little lower to
compensate for the difference in output level.
When a stereo source is connected, the signals of the left and right
inputs will be mixed to mono.
warranty info
Warranty claims and claims for hidden defects can be considered only if the
defects appear within the warranty period of 24 months and are notified
within 8 days following their appearance per registered letter. The warranty
is not valid in case of an incident, wear, for moving parts, power surges,
inadequate packing or shipping, improper use or storage and the disregard of
recommendations of Apart Audio. The warranty only concerns the spare parts
and not the involved labor, transportation or any other costs. The product
must be returned in the original packaging with the proof of purchase by an
Apart-Audio authorized reseller.
The general terms and conditions can be found here:
http://www.apart-audio.com/conditions/General_Terms_and_Conditions_
Apart_Audio.pdf