Martin audio MA9.6K, MA12K, MA18K SCHEMATICS

The Martin Experience

MA18K, MA12K & MA9.6K

User’s Guide

All material © 2007. Martin Audio Ltd. Subject to change without notice.

Contents (click appropriate item)

All material © 2007. Martin Audio Ltd. Subject to change without notice.

Important safety instructions

Warning notices

Introduction

1 Installation & operation

1.1 Unpacking

1.2 Mounting

1.3 Operating precautions

1.4 AC mains connection

1.5 Connecting inputs

1.6 Connecting outputs

1.7 Connecting remote control

2 Setup and settings

2.1 Introduction

2.2 The main screen

2.3 The main menu

2.3.1 Output attenuation

2.3.2 Gain/sensitivity

2.3.3 Input select

2.3.4 Max output voltage

2.3.5 Max mains current

2.3.6 Clip limiter Ch1 – Ch2

2.3.7 Gate Ch1 – Ch2

2.3.8 KETH

2.3.10 Bar meters

2.3.11 Output meters

2.3.12 Temperature

2.3.13 Mains meters

2.3.14 Hardware info

2.3.15 Hardware monitor

2.3.16 The SmartCard function

2.3.17 LCD contrast

2.3.18 Set unlock code – universal unlock code

2.3.19 Service

3 Protection

3.1 Turn-on/turn-off muting

3.2 Short circuit protection

3.3 Thermal protection

3.4 DC fault protection

3.5 Input/output protection

4 User maintenance

4.1 Cleaning

4.2 Service

4.3 Dust removal

5 Technical notes

All material © 2007. Martin Audio Ltd. Subject to change without notice.

5.1 Block diagram

6 Technical specifications

Important safety instructions

All material © 2007. Martin Audio Ltd. Subject to change without notice.

Caution

To reduce the risk of electric shock, do not remove the cover. No user-serviceable parts inside. Refer
servicing to qualified service personnel.

Safeguards

Electrical energy can perform many useful functions. This unit has been engineered and manufactured to
assure your personal safety. Improper use can result in potential electrical shock or fire hazards. In order not
to defeat the safeguards, observe the following instructions for its installation, use and servicing.

Approvals

* MA18K pending

This equipment has been tested and found to comply by Competent Body (Directive 89/336/EEC-EMC)
pursuant to the product family standard for audio professional use:

EN 55103-1, EN 55103-2 EN61000-3- 2 & EN 61000-3-3.

In a domestic environment this product may cause radio interferences in which case the user may be
required to take adequate measures.

This equipment has been tested and found to comply by Notified Body (Directive 2006/95/EEC L.V) pursuant
to the audio apparatus safety requirements: EN 60065.

*

Warning notices

All material © 2007. Martin Audio Ltd. Subject to change without notice.

Location

Install the amplifier in a well-ventilated location where it will not be exposed to high temperature or humidity.

Do not install the amplifier in a location that is exposed to direct rays of the sun, or near to hot appliances or
radiators.

Excessive heat can adversely affect the cabinet and internal components.

Installation of the amplifier in a damp or dusty environment may result in malfunction or accident.

Precautions regarding installation

Placing and using the amplifier for long periods on heat-generation sources will affect performances.

Avoid placing the amplifier on heat-generating sources.

Install this amplifier as far as possible from tuners and TV sets. An amplifier installed in close proximity to
such equipment may cause noise or degradation of the picture.

WARNING: To prevent fire or electric shock:

Do not expose this equipment to rain or moisture.
Apparatus shall not be exposed to dripping or splashing and no objects filled with liquids, such as

vases, shall be placed on the apparatus”.

Safety rules

This device must be powered exclusively by earth connected mains sockets in electrical networks compliant
to the IEC 364 or similar rules.

It is absolutely necessary to verify this fundamental requirement of safety and, in case of doubt, require an
accurate check by a qualified personnel.

The constructor cannot be considered responsible for eventual damages caused to persons, things or data
for the missing of accurate earth link.

Before powering this device verify that the amplifier is supplied with the correct voltage rating.
Verify that your mains connection is capable to satisfy the power ratings of the device.
Do not spill water or other liquids into or on the unit.
Do not use this unit if the electrical power cord is frayed or broken.
Do not remove the cover. Removing the cover will expose you to potentially dangerous voltage.
No naked flame sources such like lighted candles should be placed on the amplifier.

Contact the authorized center for ordinary and extraordinary maintenance.

Speaker damage

Martin Audio 9.6K, 12K & 18K amplifiers are among the most powerful professional amplifiers available and
are capable of producing much more continuous power than many loudspeakers can handle. It is the user's
responsibility to use suitable speakers with the amplifier and to use them in a sensible way that will not
cause damage.

Martin Audio will not be responsible for damaged speakers.

Even if you reduce the gain using the amplifier's front panel attenuation controls, it is still possible to reach
full output power if the input signal level is high enough. A single high-power crescendo can damage high­frequency drivers almost instantaneously, while low-frequency drivers can usually withstand very high,
continuous power levels for a few seconds before they fail. Reduce power immediately if you hear any

speaker "bottoming out" - harsh pops or cracking distortion that indicate that the speaker voice coil or

All material © 2007. Martin Audio Ltd. Subject to change without notice.

diaphragm is striking the magnet assembly.

Martin Audio recommends that you use amplifiers of this power range for more headroom (cleaner sound)
rather than for increased volume.

Consult the relevant Martin Audio User Guide paying particular attention to limiter recommendations. Our
usual limiter recommendations restrict the continuous power delivered to the loudspeaker system whilst
allowing short-term peaks to pass unhindered.

Speaker output shock hazard

A Martin Audio amplifier is capable of producing hazardous output voltages. To avoid electrical shock, do
not touch any exposed speaker wiring while the amplifier is operating.

This manual contains important information on operating your Martin Audio amplifier correctly and
safety. Please read it carefully before operating your amplifier. If you have any questions, contact
your Martin Audio dealer.

Introduction

The totally new technology employed in the Martin Audio 9.6K, 12K & 18K power amplifiers has changed the
way the world looks at professional audio amplification. No other amplifiers come close for applications
demanding high power and long term reliability. Thanks to amazing reductions in heat output along with
reductions in weight and the specific high output power, 9.6K, 12K & 18K amplifiers can be used in an
unlimited range of applications such as concert touring, opera houses, theatres, churches, cinema, theme
parks, television sound stages and industrial applications.

More sound and less weight

Compared to a conventional amplifier, Martin Audio 9.6K, 12K & 18K amplifiers offer very high efficiency and
deliver more power to the loudspeakers with much reduced heat dissipation. This greater efficiency enables
dimensions, weight and power consumption to be reduced. The output stages of the amplifiers typically run
at 95% efficiency, dissipating only 5% of the input energy as heat.

One of the most interesting characteristics is that 9.6K, 12K & 18K efficiency is almost independent of output
level. Conventional amplifiers achieve their best efficiency only at full rated power output. Since standard
music has an average power density of 40% of the maximum level, conventional amplifiers can easily
generate 10 times more heat than 9.6K, 12K or 18K amplifiers for the same volume of sound.

Superior Sound-Sonic Accuracy

Crystal-clear highs, and a tight, well-defined low end: the most accurate reproduction of an audio signal.
Patented design features ensure very high performance in parameters such as distortion, frequency
response, slew rate, power bandwidth and dumping factor.

Totally Digital with High Reliability

The 9.6K, 12K & 18K series is based on PWM technology that has been used for 30 years or more in power
supplies and inverters. PWM provides high reliability, small size, low weight and high efficiency. A PWM
converter works as a high frequency sampler, converting the variable amplitude (audio) signal into an
impulse sequence with average value equal to the audio input.

9.6K, 12K & 18K amplifiers use very high sampling frequencies to obtain high performances across the
audio band.

The Best Amplifier for Your Mains

Martin Audio 9.6K, 12K & 18K amplifiers adopt Power Factor Correction. This unique feature ensures that a
predominantly resistive load is presented to mains, minimizing current distortion and voltage/current
displacement. This leads to much improved performance of the amplifier at high levels of output and avoids
mains-voltage collapses, typical of standard and switching power supplies.

Another great advantage of this technology is that its performance is, to a large extent, independent of mains

All material © 2007. Martin Audio Ltd. Subject to change without notice.

voltage. The rated output power does not vary with load/line conditions.

Martin Audio 9.6K, 12K & 18K power amplifiers

Martin Audio 9.6K, 12K & 18K power amplifiers have many advanced features, Digital control of many
parameters, adjustable maximum mains consumption, selectable digital presets and a graphic display that
shows detailed information of the status of the amplifier. You can appreciate the functionality of these and a
lot of other features by reading this manual carefully.

The Show Always Goes On

The 9.6K, 12K & 18K Series is completely protected against every possible error in operation and is
designed to work under every condition. It gives you maximum power with maximum safety and increases
long-term reliability. Anticipating potential problems at the design stage means your show always goes on!

1 Installation and operation

All material © 2007. Martin Audio Ltd. Subject to change without notice.

1.1 Unpacking

Carefully open the shipping carton and check for any noticeable damage.

Every Martin Audio amplifier is completely tested and inspected before leaving the factory and should arrive
in perfect condition. If you find any damage, notify the shipping company immediately. Be sure to save the
carton and all packing materials for the carrier's inspection.

1.2 Mounting

All 9.6K, 12K & 18K amplifiers will mount in a standard 19" rack. Four front panel mounting holes are
provided.

Your 9.6K, 12K & 18K amplifier uses a forced-air cooling system to maintain a low, even operating
temperature. Drawn by an internal fan, air enters through the slots in the front panel and courses over and
through components.

The 9.6K, 12K & 18K series amplifiers feature an "intelligent" variable-speed DC fan which is controlled by

All material © 2007. Martin Audio Ltd. Subject to change without notice.

heat sink temperature sensing circuits: the fan speed will increase only when the temperature of either heat
sink requires it, which keeps fan noise to a minimum and helps cut dust accumulation inside. Under extreme
thermal load, the fan will force a very large volume of air through the heat sinks.

If either heat sink gets too hot, its sensing circuit will reduce the output power. If the amplifier overheats,
another sensing circuit shuts down its circuit to cut off power until it cools to a safe temperature. The exhaust
cooling air is forced out through the rear of the chassis (see below), so make sure there is enough space
around the sides of the amplifier to allow the air to escape. If it is rack mounted, make sure the exhaust air
can flow without resistance. If you are using a rack with closed backs, there must be at least one standard
rack space of opening in the front of the rack for every four amplifiers. Amplifiers may be stacked directly on
top of each other (no space needed between units), starting from the bottom of the rack.

1.3 Operating Precautions

Make sure the AC mains voltage is correct and is the same as that printed on the rear of the amplifier.
Damage caused by connecting the amplifier to improper AC voltage is not covered by the warranty. Make
sure the power switch is off before making any input or output connections.
It is always a good idea to have the gain controls muted during power-up to prevent speaker damage if there
is a high signal level at the inputs.

Whether you buy them or make them, use good-quality input and speaker cables. Most intermittent problems
are caused by faulty cables. Use good-quality connectors and wire, along with good soldering technique, to
ensure troublefree reliability.

1.4 AC Main connection

The AC Main connection is made via the CPC type connector on the rear side of the panel. The figure below
shows the connection to the amplifier. Be sure that your AC mains power source has the requirements
indicated in this manual. 9.6K, 12K & 18K amplifiers have an automatic power factor correction system for a
perfect mains network interface. The amplifier is a resistive load for the mains network, minimizing the
reactive power and the harmonic distortion on the current. The system allows performance to be maintained
even in circumstances of varying the mains voltage. Is important to connect the ground for safety, do

not use adapters that disable the ground.

1.5 Connecting Inputs.

Input connections are made via the 3-pin XLR-female type or 1/4" phone Jack connectors on the rear side of
the amplifier.

All material © 2007. Martin Audio Ltd. Subject to change without notice.

The figure below shows the connection of analog input for balanced and unbalanced line. You can use both
configurations, but you must consider that unbalanced long line can introduce noise in the audio system. The
Link switch located in the rear panel is for direct paralleling the rear input connectors. You can use the
remaining input connector to carry signal to other amps.

1.6 Connecting Outputs
Warning: there are lethal voltages at the loudspeaker connectors when the amplifier is turned on. To
prevent damage turn the amplifier off before connecting the loudspeaker.

Output connectors are made via neutrik speakon connectors. Consult the wire gauge chart to find a suitable
wire gauge to minimize power and damping factor losses in the speaker cables. The outputs can also work
in bridge mode. For each device the 1+ and 2+ pins of speakon connector are connected inside and have to
be considered the positive output of the channel; the 1- and 2- pins of speakon connector are connected
inside and have to be considered the negative output of the channel.

Note: Channel B is internally polarity reversed. Because the internal polarity is corrected by feeding the
minus pins of the channel B output with the output voltage, the amplifier outputs work in-phase as far as the
user is concerned.

By having channel A and B operating in opposite polarity, internally, the energy storage in the power supply
is more efficient. This is significant for signals below 100Hz (sub bass etc.) and improves the power
bandwidth.

Be sure to use balanced inputs on all measurement equipment (also oscillator probes) in you are
bench testing.

1.7 Connecting Remote Control

All material © 2007. Martin Audio Ltd. Subject to change without notice.

You can control the amplifier via a RS485; The illustration shows the connection of the data cable to the plug
located to the rear panel of the amplifier. connection.

The same picture shows also the ID selection for Remote Control (in this case ID= 28); to change the ID,
rotate the selectors at the desired value.

2 Setup and settings

All material © 2007. Martin Audio Ltd. Subject to change without notice.

2.1 Introduction

The figure below shows the front panel of 9.6K, 12K & 18K Series. The front panel controls, in conjuction
with the graphic LCD display above the buttons, give to the user the total control and detailed information
about the status of the amplifier. Each pushbutton has multiple functions and the display shows the current
active function for each button. Read carefully the instructions below that help you to manage the functions
of the amplifier.

2.2 The main screen

The illustration below shows the main screen; this screen appears after a short presentation when the user
powers on the amplifier. In the first line, after power on, "WAIT" appears; if the system parameters are
normal, this is replaced with "READY". During the normal operation the controller monitors the system
parameters.

If a paramenter is out of range, the correspondent code error appears on the LCD meter of the relative
channel in the third line; if the abnormal parameter is associated to both channel, the error code appears in
the center.

The LED bars can function as output voltage or output current meters; in the first case the LCD meters
function as output current meter, vice versa in the second case. The first green LED at the bottom side of the
LED bar indicates, when lighted, the presence of input audio signal above -60 dBV on the corresponding
channel.

From the second green LED to the yellow one, each LED represents 3dB. The green LEDs will be lit during
normal working. The yellow LED will lit at -2 dB. If the level of the audio signal reach the channel output
capability, a red LED will be triggered.

The LED bars have diagnostic function also; a flashing yellow LED indicates a critic range of temperature
(from 80°C to 85°C) of the power devices on the corresponding channel, if this LED is lit continuously, the
temperature is above 85°C. A continuously lit red LED indicates that the corresponding channel is in
protection.

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The fourth line of the screen shows the functions of the buttons below.

The "lock" function is activated if the corresponding button is pressed more than 1 second; in this case all
the other buttons are locked. The same operation unlocks these buttons (unlock code is required - see
section 2.3.18 for more details).

The "mute" buttons switch off the two channels independently; in this case the writing "muted" appears on
the first line. The same operation disables the mute function.

If the "menu" button is pressed, the main menu is displayed on the LCD screen.

2.3 The main menu

The illustration shows the main menu. You can scroll the menu items by pushing the up or down buttons and
choose the selected one by pushing "ok" (if the chosen item enables or disables a function, the writing "on"
is replaced with "off" for disabling it, or "on" for enabling it. See below for menu tree.

All material © 2007. Martin Audio Ltd. Subject to change without notice.

2.3.1 Output attenuation

The illustration below shows the Output attenuation screen. You can choose to set CH1, CH2 or both by
pushing the "C1+2" button. The "+" and "-" buttons change the value of the output attenuation in the range
from 0 to -30dB. Note: for the best sonic performance it is preferrable to set the output attenuation to

0dB (no attenuation), and select the proper gain/sensitivity by the following menu.

2.3.2 Gain/Sensitivity

The illustration below shows the Gain/Sensitivity screen. You can choose to set CH1, CH2 or both by
pushing "C1+2" button. The "+" and "-" buttons change the value of the gain. The values of gains permitted
are 26, 29, 32 and 35 dB.

2.3.3 Input select

You can choose among two different input modes (if available): Analog and Ethernet. The up and down
buttons change the selection; the "sel" button locks the selected option.

2.3.4 Max output voltage

The illustration below shows the Max output voltage screen. You can choose to set CH1, CH2 or both by
pushing "C1+2" button. The "+" and "-" buttons change the value of the max output peak voltage.

All material © 2007. Martin Audio Ltd. Subject to change without notice.

2.3.5 Max mains current

The Max mains current screen is shown below. The "+" and "-" buttons change the value of the max mains
current input in the range from 15 to 32A.

2.3.6 Clip limiter CH1 - CH2

Enable this function to prevent the distortion due to excessive amplitude of output signal. You can
enable/disable it by pushing the on/off button.

CAUTION: There is the risk of damage to the loudspeakers, if Clip Limiters are deactivated. You
should not deactivate Clip Limiters unless their function is taken over by external devices, such as
digital system controllers. In such cases it is mandatory, to properly adjust parameters in the
external device.

2.3.7 Gate CH1 - CH2

This function allows to mute the amplifier channels individually if input signal amplitude is falling below the
values shown in the following table. You can enable/disable it by pushing the on/off button. Gating the output
is delayed by 5 seconds after input signal removal, and follows in reversed way the bottom green LED on the
CH1, CH2 bar LED display *(muted if green LED is off).

2.3.8 KETH

This section is not currently implemented.

2.3.10 Bar meters

In the Bar meters screen you can choose if the LED bars operate as output voltage meter and LCD bar in
the main screen as output current meter (by selecting "LED Volt, LCD Curr), or vice versa (by selecting the
other item).

All material © 2007. Martin Audio Ltd. Subject to change without notice.

2.3.11 Output meters

In the Output meters screen you can view the values of the output signal for CH1 and CH2. Furthermore, the
impedance of the load is showed in the bottom line of the screen (see illustration). Minimum of output
voltage for impedance measurements is 10Vrms, measurements values are stored into logbook. Time
between single impedance measurements can be up to several minutes depending on program signal.
Output power is shown as maximum value every 200 mS.

C1+C2 shows the output values are being shown in bridge mode.

2.3.12 Temperature

In the Temperature screen you can view the historic temperature diagram of the last four hours of the final
current use in the range from 10 to 90°C; in the bottom-right side of the screen there is the present value.

2.3.13 Mains meters

In the Mains meters screen you can view the voltage and the current of the mains.

2.3.14 Hardware info

In this screen you can view some information about the hardware of the amplifier:

S/N the serial number of the amplifier
HW ID the hardware identifier

If you push the "more" button, you can view the other info

KFRNT the version number of the front panel
KCTRL the version number of the controller
KETH the version number ethernet adapter

Lifetime the operating time of the amplifier

All material © 2007. Martin Audio Ltd. Subject to change without notice.

2.3.15 Hardware monitor

In this screen you can view some information about the system parameters:

PWRBSCH1 - PWRBSCH2 amplifier power supply voltages channel 1-2
VAUX internal auxiliary voltages

If you push the "more" button, you can view the others parameters:

+5VAN auxiliary analog voltage
VEXT external remote control voltage
VAUX if the "OK" written is displayed, auxiliary voltages of power supply are correct.
IGBTCONV if the "OK" written is displayed, the DC/DC converter monitor function properly
192KHZ if the "OK" written is displayed, the frequency system clock is right

2.3.16 The Smartcard function

The Smartcard operates as memory and can save the settings of the amplifier. These settings can be loaded
into other amplifiers avoiding the manual setup of these. When you insert the smartcard in the slot over the
LCD screen), the screen shown below appears.

You can select the desired option by pushing up or down button and "ok" to activate it. The option "Recall

local preset" does not appear if the smartcard is blank.

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2.3.17 LCD contrast

In this screen you can set the contrast of the LCD display by pushing the +/- buttons (see figure 2.3.10)

2.3.18 Set unlock code

In this screen you can insert the numeric key to unlock the settings. The same screen appears when the
“unlock” button in the main screen is pressed. There is a universal key to unlock the settings. This is 270156

2.3.19 Service

This function is factory reserved.

.

All material © 2007. Martin Audio Ltd. Subject to change without notice.

3 Protection

3.1 Turn-On/Turn-Off muting

For about four seconds after turn-on, and immediately at turn-off, the amplifier outputs are muted.

3.2 Short circuit protection

A short circuit protection system safeguards the amplifier's output transistors under short circuits and other
stressful loads. It is completely inaudible when inactive. In case of short circuit, the red LED will be light-up
and writing "PROT" appears in the first line of the display (see Par. 2.2 for a detailed description). The
amplifier will reset himself 50 times every 2 seconds. Once 50 resets have been performed and the fault still
exisst on the output, the unit sets into steady protection mode. Turn ON/OFF cycle is needed to restart the
unit.

3.3 Thermal protection

The 9.6K, 12K & 18K amplifiers use a continuously variable speed fan to assist cooling (the fan speed
changes in response to the amplifier's cooling needs). If the heat sink temperature reaches approximately
80°C, the yellow LED starts to flashing. If the temperature is more then 85°C the thermal sensing circuitry
will mute each power section channels, the LED will light permanently and the power supply will be cut off.
Once the heatsink has cooled down, the amplifier will automatically reset and the LED will be go out. It is
possible to reduce the temperature by reducing the output power.

3.4 DC fault protection

If DC or excessive subsonic energy appears at a channel output, an instantaneous protection circuit will cut
off the power supply for both channels. Power supply shutdown is used instead of speaker relays, thereby
improving the damping factor and reliability of the 9.6K, 12K & 18K amplifiers.

3.5 Input/Output protection

An ultrasonic network decouples RF from the outputs and keeps the amplifier stable with reactive loads.

All material © 2007. Martin Audio Ltd. Subject to change without notice.

4 User maintenance

4.1 Cleaning

Disconnect the amplifier from the AC main source first; use a soft cloth and mild non-abrasive solution to
clean the faceplate and chassis.

4.2 Service

There are no user-serviceable parts in your 9.6K, 12K or 18K amplifier. Refer servicing to qualified technical
personnel.

If your 9.6K, 12K & 18K amplifier needs repair, contact your Martin Audio dealer or distributor.

4.3 Dust removal

Especially in a dusty environment, the front side filters clog with dust after prolonged use, this will interfere
with cooling. You may use compressed air to remove the dust from filters.

To remove air filters unscrew the retaining screws and rotate the covering grill; repeat the same operation on
the other side.

All material © 2007. Martin Audio Ltd. Subject to change without notice.

5 Technical notes

5.1 Block diagram

The illustrations below show the output stage block diagram and the power supply block diagram.

6 Technical specifications

All material © 2007. Martin Audio Ltd. Subject to change without notice.