PARK AUDIO RX Series User manual

series
9d
FOUR CHANNEL PROFESSIONAL
SWITCHING POWER AMPLIFIER
Owner’s Manual

ACCESSORIES
1. Power Cord 1 pc.
2. Dust filter 2 pcs
3. Owner’s Manual 1 pc.
4. Warranty 1 pc.

CAUTION
RISK OF ELECTRIC SHOCK
DO NOT OPEN
AVIS
RISQUE DE CHOC ELECTRIQUE
NE PAS OUVRIR
CAUTION!
The amplifier runs on 230 V AC voltage. Removing the cover will expose you to a
potentially dangerous voltage! Do not use the unit if the electrical power cord is
frayed or broken.
Power is supplied from 230 V AC single-phase grounded 50/60 Hz source!
CAUTION!
To reduce the risc of fire or electric shock, do not expose the amplifier to rain or
moisture!
CAUTION!
The amplifier can yield dangerous output voltage! Do not touch the non-insulated
cable parts, connected to the unit in operation!
CAUTION!
The high sound pressure caused by the high output signal, applied to speaker
systems, may endanger your hearing. Please, take care to observe the required
safety precautions.
WARNING SIGNS:
Important information! Intended to warn the user about any important
information contained in this Owner’s Manual.
Hazardous voltage inside! Intended to warn the user about electric shock
hazard due to high voltage inside the product.
This sign next to the output terminals warns about dangerous voltage while in
operation.

22
GENERAL
The four-channel professional power amplifier RX9d is designed for sound signal
high-fidelity amplification within professional sound reproduction systems.
The amplifier is equipped with built-in DSP engine (DFM audio, Germany), which
provides the precision processing of the audio signal. To control the parameters of the
amplifier (or group of amplifiers) the program NetControl is used, the amplifiers are
connected via the ETHERNET interface.
To ensure faultless operation of amplifiers, please, take time to read this Manual
before use.
WARNING!
Make sure to take all precautions where required.
Please, follow all instructions and guidelines.
To avoid any risk of electrical shock and/or fire hazard, please, do not expose this unit
to rain or moisture. Do not use this unit near open water.
Use dry cloth to clean the unit.
Do not block fan vents.
Do not place the unit near heating radiators, furnaces or other heat-emitting devices.
Do not connect this unit to an ungrounded power supply line.
Protect the power cord against damage.
Disconnect the unit from power supply in case of thunder or during downtime.
In case of malfunctioning, caused by water or any other foreign matter inside or when
the unit has been dropped, or the power cord has been damaged, or the unit has
been found faulty, please, consult qualified personnel.
WARNING!
The amplifier yields high output power. The manufacturer shall not be held respon-
sible for any damage to the speakers caused by excessive power from the unit.
UNPACKING
The manufacturer’s quality control system provides for careful examination of each
product before it leaves the factory to ensure its flawless appearance. After unpacking,
please, check the unit for any physical damage. In case of damage, please, contact your
local dealer. Keep the shipping carton and all packing material, as you may require them
for reshipment of the unit.

3
DESIGN FEATURES
Physical Design
The amplifier is enclosed in a metal (steel) case of 2U height. The amplifier is
designed to be installed into a standard 19" rack.
The amplifier must be fixed at four points, when installed in the RACK 19 "(two points in
front and two at the rear).
Power Supply Unit
Two independent switch-mode PSU. Individual for each pair of channel.
Cooling System
Forced, cooling rate smooth adjustable system.
Two powerful fans. Backward air flow direction.
Dust Filter
Two removable filters are located on the front panel under protective covers.
Covers can be removed and installed without the use of any tools.
Power Amplifier Units
RX9d amplifier is based on a modern, high performance D class topology.
This topology provides high efficiency, low heat generation and large output power At
the same time, the high switching frequency of the output stage (450 kHz) provides sound
quality comparable with the best analog amplifiers.
Analog inputs
The amplifier is equipped with four balanced analog inputs (XLR female).
The use of balanced inputs provides for an essential reduction of the environment-
induced hum and noise interference with long input connecting cables.
For DSP processing, the analog signal is converted to digital using four 24-bit A/D
converters, operating at 96 kHz. The dynamic range of A/D and D/A converters is 120 dB.
AES inputs
Inputs of channels 1 and 2 can be switched to digital input mode.
A digital AES/EBU two-channel audio signal can be applied to each input. Sound
signals can be sent to an amplifier from a digital mixing console or other device, that
generates a digital audio signal AES/EBU (AES3). The AES/EBU inputs have balanced
transformers and are protected against static electricity. Built-in sample rate converters
support a wide range of input formats (16-24 bit / 44.1-192 kHz), converting any of them into
internal format 24bit / 96kHz.
ETHERNET connectors
Two equivalent ports for connection to the ETHERNET network.
Provide the ability to configure and remotely control the amplifier over a network, using
the NetControl software. The built-in router allows you to connect multiple amplifiers in
chain.
Line Outputs
Four XLR connectors (male).
Provide the possibility of parallel connection of several amplifiers, using standard
signal cables.

When analog input signal is used, the line outputs are connected in parallel to the
corresponding line inputs. When the digital input signal is used, the outputs are connected to
the corresponding inputs via buffer amplifiers.
DSP engine
The amplifier is equipped with a flexible and powerful high-end DSP from
DFM audio, Germany.
The close integration of processing and amplification allows the DSP to monitor and
better respond to amplifier behavior, making dynamics processing far more accurate and
effective than that typically achieved with separate components. The onboard DSP offers
four channels of crossover filters, parametric EQ, FIR filter and alignment delay – everything
needed to optimize a loudspeaker system.
Flexibly configurable RMS and PEAK limiters in each channel ensure reliable
loudspeakers overload protection.
DSP settings control is performed via ETHERNET, using personal computer with the
installed NetControl software.
For use in large installations, the processor has the tools for group control of many
amplifiers simultaneously. The amplifier can be supplied with pre-formed library of passive
speakers.
Software is designed for group control of a large number of amplifiers
simultaneously. The program provides the ability to create virtual systems, which can be
automatically merging with real amplifiers.
It is based on the work with Speaker and Preset libraries. The amplifier can be supplied
with pre-installed Speaker libraries. Also, the user can update the Speaker library or create
his own library. When creating a sound system, the user simply selects the desired type of
loudspeaker from the library.
The NetControl installation package and user manual can be downloaded from
parkaudio.ua (’’Downloads’’ section on the RX9d amplifier page).
User Interface
LCD display, LED indicators and controls (encoder and 4 buttons with illumination).
LED indicators on the front panel shows a signal presence, limiters activation and the
overload of each amplifier channel. Encoder, LCD and buttons provide local access to
navigation and DSP control.
Removable Power Cord
NEUTRIK powerCON 20A.
This feature is provided for convenience of transportation and rack mounting.
4

FUNCTIONAL FEATURES
Output Overload and Short-Circuit Protection
Individual per each channel. Protects the output stage of the amplifier units against
short-circuiting, as well as limits the output current, when a maximum-level sine signal is
applied continuously to 2-Ohms loudspeaker.
In case short-time overload (e.g. overload, caused by a sudden drop of complex load
impedance), the fast output stage protection system limits the output current to 60A.
In case of long-term overload (>0.5sec), the slow protection system limits the output
current to 40A.
In case of a short circuit, the protection system momentarily blocks the output of the
amplifier. The processor periodically tries to turn on the amplifier. If the short-circuit persists
for a long time, test attempts are made less often.
The protective system does not switch the amplifier off, so it resumes its unattended
operation after the short-circuiting conditions are gone.
Built-in to each channel microprocessor ensures safe operation.
DC Output Protection
Independent for each pair of channel. Prevents DC damage to loudspeakers.
The amplifier’s schematics precludes transit of any clicks or noise during the power-
on/off transition process.
Protection of loudspeakers against DC damage is ensured for each pair of channel by
individual power supply units which are disabled in the event of output DC voltage or any
powerful LF fluctuations. In case the protection system becomes active on all channels and
both power supply units become disabled, all indicators go off.
The amplifier can be restarted with the POWER toggle switch, by way of turning the
amplifier off and turning it on, about 2 minutes later again.
Thermal Protection
Individual for each channel. Protects the amplifier’s output stage against
overheating.
In case the temperature of the output stage transistors rises to 80°С, the CLIP LED of
the corresponding channel lights up. At the same time, the thermal protection system will
gradually reduce the signal level as the temperature increases. When the output stage
reaches 85°C, the thermal protection system will block the input and output stage of the
corresponding amplifier channel. After the temperature drops to 70°С , the amplifier
automatically resumes operation.
Soft Start
Reduces the power-on inrush current.
The soft start system is provided to reduce inrush current to the amplifier and to
minimize the noise contributed by the amplifier to the power mains during the poweron
process.
Soft Signal Start
Ensures smooth power-on sound signal rise.
During the power-on process, this feature ensures smooth gain from zero to the
maximum level to provide for a smooth rise of the sound level emitted from the
loudspeakers.
5

Overvoltage Protection System
Relay system. Used to protect the amplifier against overvoltage in the mains.
In case of accidental connection of the amplifier to incorrect-wired mains, the inter-
phase voltage of 400V may be applied to the amplifier. In this case the protection system
will block the mains connection to the power supply. Only the protection system stand-by
power supply unit remains in operation. The system activates, whenever the mains
voltage exceeds ~265V. The amplifier automatically resumes operation after the mains
voltage goes down to ~260V.
Microcontrol Monitoring
All amplifier protection systems are controlled by the microcontrollers, built into each
channel of the amplifier. Microcontrollers constantly monitor protection and control
systems, which increases the overall reliability and fault tolerance of the amplifier.
6

7
AMPLIFIER BLOCK DIAGRAM
1+
1+
2+
2+
1+
Ch1/AES1-2
INPUT
Power
amplifier
Ch 1
1+
2+
2+
THRU
THRU
Ch1, Ch2
OUTPUTS
TO SPEAKERS
Ch2
Ch 2
Ch 3
Ch 4
THRU
THRU
Ch3, Ch4
Ch4
Ch2/AES3-4
Ch 3
Ch 4
INPUT
INPUT
INPUT
DSP

8
FRONT PANEL
Dust filter cover grills.
POWER – выключатель питания усилителя.
SIGNAL LEDs indicating output signal on Channels 1... 4.
LIMIT – Channel 1,2,3 and 4 limiters activation LEDs.
CLIP – overload LEDs for channels 1, 2, 3 and 4.
Indicating overload and distortion occurence.
2 x 20 characters LCD display
DSP CONTROL – encoder knob for the menu navigation and parameters setting.
SEL/MUTE – channel selection for setting parameters/ mute corresponding channel.
1
2
3
6
7
8
1 1
4x2200 W
2 5
4673
8
5
4

REAR PANEL
INPUTS (Ch1/AES1-2, Ch2/AES3-4, Ch3, Ch4) – balanced inputs (XLR
female). For analog signal connection Ch1/AES1-2, Ch2/AES3-4, Ch3, Ch4
are used. For digital signal connection Ch1/AES1-2 and Ch2/AES3-4 are
used.
Analog/digital signal choise is performed via local amplifier interface or
NETControl software.
Output fan grill.
SPEAKER OUTPUTS – output SpeakOn connectors for speakers
connection. Connectors pin assignment are marked on the amplifier rear
panel.
MAINS IN – mains cable connector.
THRU – line outputs. Used for sending the input signal to another amplifiers.
In analog signal mode THRU connectors are parallel to corresponding
INPUTS (Ch1/AES1-2, Ch2/AES3-4, Ch3, Ch4). In digital mode THRU
connectors (Ch1/AES1-2, Ch2/AES3-4) are linked to corresponding inputs
via buffer amplifier.
ETHERNET 1, ETHERNET 2 – RJ45 connectors for ETHERNET network
connection.
1 2 3
9
4
5 8
6 7 10 11
12 17 13 16
Ch3Ch4
INPUTSTHRU
ETHERNET 2 ETHERNET 1
Ch1/AES1-2
Ch2 /AES3-4
31 42 5 86 7 9
11 10
Serial No
17 12 1615 14 13
17 16
9

10
CABLE REQUIREMENTS
Input Cables
Make sure to use only shielded cables whether balanced or unbalanced. Shielding
when properly grounded, protects a signal against external electrical interference. As a
rule, unbalanced lines of over 3 meters long are not acceptable. Greater distances require
a balanced cable.
Avoid placing input cables close to power cords or power transformers.
Output Cables
The amplifier is capable of delivering high level output current; therefore, the wire
gauge used for speaker cables is particularly important. Inadequate wire gauge adds
significant resistance to the speaker’s own impedance, reducing the power which is
actually delivered to the speaker. It will also result in a decreased damping factor and
possible fire hazard.
Since the power applied to the loudspeaker is of primary concern in system design,
we have included the table below to allow you determine the appropriate wire gauge for
your application.
The table shows the percentage of the power loss in a 10-meter copper multiple-core
cable. This table reflects the power loss as a percentage of the output power of the
amplifier applied to the load. Use this table to determine the power loss to the load at other
cable lengths. For example, if you plan to deliver 1000 Watts to 2-Ohm load through 20 m
of 2.5-mm 2 cable, the power loss in the cable would be 7 % x 2=14 % of 1000 W or 140 W
lost in the cable.
2
1.50mm
2
2.00mm
2
2.50mm
2
4.00mm
2
6.00mm
0.24Ohm
0.18Ohm
0.15Ohm
0.09Ohm
0.06Ohm
10.7 %
8.3 %
7 %
4,3 %
2.9 %
2.9 %
2.2 %
1.8 %
1.1 %
0.7 %
5.7 %
4.3 %
3.6 %
2.3 %
1.5 %
Wire Gauge Cable
Resistance
Cable Power Loss
2Ohm Load 8Ohm Load4Ohm Load

11
INPUT AND OUTPUT CONNECTORS
Input Connectors
Use XLR (male) connectors to connect to the amplifier inputs and XLR (female)
connectors to line outputs.
Output Connectors
Use SpeakON NL2FC or NL4FC connectors to connect speaker systems to the
amplifier individual channel outputs. For connection of both channels via a single cable,
use SpeakON NL4FC.
CAUTION! Never attempt to jumper or otherwise link up any pins of output
connectors.
21
3
2 1
3
-
1
1+
-
1
2+
1+
-
2
-
1
2+
1+
-
2
XLR Wiring (male)
XLR Wiring (female)
–
( )
Cold
Shield (Ground)
( )
Hot +
–
( )
Cold
( )
Hot +
Shield (Ground)
NL2FC for individual channel linking up
Output +
Output –
NL4FC for individual channel linking up
Output +
Output –
NL4FC for linking up two channels with a single connector
Channel 1 (3)
output +
Channel 1 3
output –
Channel 2 (4)
output –
Channel 2 (4)
output +

12
RACK-MOUNTING REQUIREMENTS
The amplifier is designed to fit a standard 19” rack. While mounting, make sure to
provide unhindered air access to the front and rear sides of the rack. The fan blows air
backwards. It is not necessary to leave empty space above or below the amplifier. Prior to
installing the amplifier into the rack, remove the rubber feet from the amplifier bottom
panel. Fix the amplifier at four points, when installed in the RACK 19 "(two points in front
and two at the rear). Where required, use a adaptor bracket (optional) to extend the
mounting depth of the amplifier mounted into the rack.
AC POWER REQUIREMENTS
Use V 50/60Hz single-phase grounded mains.~220/230
The quality of the AC power supply mains is of prime importance for the amplifier
functioning. The amplifier should be powered from the mains designed for at least
1.5times the average current consumed by the amplifier.
Never try to connect the amplifier to a household mains.
If connected to weak power supply mains, the output power of the amplifier may be
reduced producing the so-called «feeble bass» effect, or the power supply line may be
damaged.
Use the power cord, supplied with amplifier.
Before connecting, please, make sure that there are no other devices consuming
much AC current, as the normal operation of such several devices may be impossible. In
the event of line voltage sag, the unit will continue to operate normally, albeit with less
power.
The actual AC current consumption by the amplifier depends on the type of the music
program and the load impedance. While installing the audio systems, in order to optimize
the power wiring, please, note that for reproduction of typical audio material at the full
output level, the average current consumption rate is as follows:
– 8 A for operation at 8 Ohm (for all channels);
– 13 A for operation at 4 Ohm (for all channels);
– 16A for operation at 2 or 2.7 Ohm (for all channels).
In order to minimize the AC current hum and noise, make sure to plug all audio devices
interconnected with signal cables, into the same mains outlet.

AMPLIFIER SETUP
DSP settings control is performed via ETHERNET, using personal computer with the
installed NetControl software.The NetControl installation package and user manual can
be downloaded from parkaudio.ua (’’Downloads’’ section on the RX9d amplifier page).
Some DSP engine settings are available in the amplifier system menu.
VOLUME – signal level setting for each
channel.
DELAY – delay setting for each channel.
LOAD PRESET – presets loading from
Preset Library (memory cell 1 ... 92).
Applied to all channels simultaneously.
SET SPEAKER – Speaker presets load-
ing from Speaker Library (memory cells 93
... 190). Applied to all channel separately.
STORE PRESET – current setting store as
user preset into Preset Library ( in one of
the memory cells (1 ... 92).
SETUP IP – amplifier IP address setting.
SELECT INPUT – input mode choise
(analog or digital AES/EBU).
SYSTEM TEMPERATURE – amplifier
temperature.
AMPLIFIER INFO information about –
amplifier.
AMPLIFIER STATE amplifier state –
information. Shows error codes.
Enter the menu by short clicking the encoder knob DSP CONTROL.
Ch1: –80 ... +15dB
1 ... 92
Analog/Digital
CH1: 0 ...1500ms
CH2: 0 ...1500ms
CH3: 0 ...1500ms
CH4: 0 ...1500ms
1 ... 92
CH1: 93 ... 190
CH2: 93 ... 190
CH3: 93 ... 190
CH4: 93 ...190
STORE PRESET
LOAD PRESET
SETUP IP
SELECT INPUT
VOLUME
DELAY
SET SPEAKER
SYSTEM
TEMPERATURE
AMPLIFIER
INFO
AMPLIFIER
STATE
Ch1: –80 ... +15dB
Ch1: –80 ... +15dB
Ch1: –80 ... +15dB
13
Choose the needed menu item by knob DSP CONTROL rotation.
Current menu item is marked by the arrow cursor (left and right).

14
To make changes in the current menu item short click the DSP CONTROL knob.
Rotating the DSP CONTROL knob set the needed parameter setting.
In this menu item (VOLUME) signal level for each channel is set. The desired
channel is chosen by clicking SEL/MUTE button for the corresponding channel. The
channel number is indicated in the upper line of the LCD-display. Rotating the
DSP CONTROL knob changes parameter with step 0.1dB. The step can be changed
from 0.1dB to 1dB and vice versa by short clicking DSP CONTROL knob.
No parameters confirmation needed. It is enough to choose another channel or exit
from current menu item. To exit current menu item press and hold DSP CONTROL knob.
When the power is turned off, the amplifier remembers the current settings. When
amplifier is turned on again, all previous settings will be restored automatically.

15
MAINTENANCE
Cleaning of Dust Protective Air Filter
No special tools are required for removing the filter.
Filters are located under the cover grills on the front panel. To remove the cover, take
the edge of the hole with your finger (shown in the figure below) and pull it toward. The
locking latch must be unlocked. After that, carefully remove the cover and the filter. A
heavily dusted filter can be washed in any synthetic detergent, thoroughly rinsed and
dried.
In case the filter is worn out, replace the filter with a spare one supplied.
ATTENTION! Never install a wet filter.
Do not dry the filter with hot air or expose it to direct sun rays.
4x2200 W

SPECIFICATIONS
Output Power:
– 2-2.7 Ohm 4 х 2500 W (~230 V)
– 4 Ohm 4 x 2200 W (~230 V)
– 8 Ohm 4 x 1200 W (~230 V)
Peak Output Voltage 168 V
Frequency Responce 20 Hz – 20 kHz (±0.5 dB, Pnom.)
Total Harmonic Distortion 0.02% (20 Hz – 20 kHz)
Slew Rate 60 V/µs
Damping Factor 600 (1 kHz, 8 Ohm)
Crosstalk 60 dB (1 kHz)
Signal-to-Noise Ratio 100 dB (unweighted)
Input Impedance 10 kOhm (balanced)
Gain 35 dB
Power Requirements ~230 V, 50/60 Hz
Weight 12 kg
Dimensions 482 mm (W), 96 mm (H), 442 mm (D)
DSP Parameters SHARC DSP,
96 kHz sampling rate / 40 bit floating
point
ADC: 120dB SNR , -100 dB THD/N,
+18 dBU Input Level
DAC: 120 dB SNR , -104 dB THD/N,
+18 dBU Output Level
DSP Functions Crossovers.
20 PEQ per channel.
Delay up to 1.5sec/channel.
RMS and Peak Limiters.
Two banks of FIR filter (500 tap each)
per channel.
Speaker library (96 speaker).
92 user presets.
OPERATING CONDITIONS
Air Temperature: 5 ... 50°C
Atmospheric Pressure: 86.6 ... 106.7kPa (650 – 800 MMHG)
Relative Humidity: less than 80%
16

4x2200 W
DIMENSIONS
482
440 max
439
442
465
76
88
96
428
12
17

PARK AUDIO II, Ltd. Vinnytsia, Ukraine
www.parkaudio.ua
[email protected]