PARK AUDIO GS Series User manual

GS4d
GS5d
GS6d
GS7d
GS8d
GS series
Park Audio
TWO-CHANNEL
PROFESSIONAL POWER AMPLIFIERS
WITH DSP
Owner’s Manual

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

TABLE OF CONTENTS
Стр.
Safety Precautions. . . . . . . . . . . . . . . . . . . . . . . . . . . 2
General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Unpacking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Design Features. . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Functional Features . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Front Panel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Rear Panel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Input and Output Connectors . . . . . . . . . . . . . . . . . . . . . . . 11
Cabel Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . 12
AC Power Requirements . . . . . . . . . . . . . . . . . . . . . . . . 13
ack-Mounting Requirements . . . . . . . . . . . . . . . . . . . . . . . 14
Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Amplifier Setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Operating Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Dimensions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

2
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.

3
GENERAL
The two-channel professional power amplifiers series with DSP are designed GS
for sound signal high-fidelity amplification within professional sound reproduction
systems.
The amplifiers are 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.
This manual applies to any GSd series amplifier:
–GS4d – 2 х 2000W into 2Ohms;
–GS5d – 2 х 2500W into 2Ohms;
–GS6d – 2 х 3000W into 2Ohms;
–GS7d – 2 х 3500W into 2Ohms;
–GS8d – 2 х 4000W into 4Ohms;.
ATTENTION!
The GS4d, GS5d, GS6d, GS7d, GS8d amplifiers have the same design and
functional features and differ only in the schematics elements, output power and
weight. Unless specified otherwise, the word “amplifier” hereinafter applies to any of
the above models.
To ensure the most advantageous and faultless operation of the amplifier, please,
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 amplifiers yield high output power. The GS4d, GS5d, GS6d, GS7d, GS8d
manufacturer shall not be held responsible for any damage to the speakers caused
by excessive power from the unit.

4
DESIGN FEATURES
Physical Design
The amplifier is enclosed in a metal (steel) case of 2U height. Amplifier front panel
is made of aluminum.
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 Source
Switchable. Individual for each channel.
Cooling System
Forced, cooling rate smooth adjustable system.
Four fans, two per each channel. Backward air flow direction.
Dust Filter
Front panel filter easily removable/replaceable for periodic maintenance.
Power Amplifier Unit
Based on TD Class schematics.
TD Class power amplifier combines the best features of both Class D and analogue
amplifiers. The amplifier boasts the efficiency comparable to Class D amplifiers and
sound quality typical of analogue amplifiers.
Analog inputs
The amplifier is equipped with 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 input
Input of channel 1 can be switched to digital input mode.
A digital two-channel audio signal can be applied to input. Sound signals can AES/EBU
be sent to an amplifier from a digital mixing console or other device, that generates a digital
audio signal (AES3). The inputs have balanced transformers and are AES/EBU AES/EBU
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.

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
Switchable. XLR (male).
Allows to appply signal to another amplifier. SWITCHED OUTPUT located on the
rear panel allow to choose signal applied to line outputs.
Note.
*In the case of amplifier power failure, the line output is connected to the line input via
relay, providing uninterrupted signal transit.
Input Signal
AES1-2 Digital Signal
(line output
connected to input via
buffer amplifier*)
CH1 Analog
Signal
CH2 Input Analog Signal
(line output connected
parallel to input)
CH1 Input Analog Signal
(line output connected
parallel to input)
AES1-2
Digital Signal
CH2 Analog
Signal
CH2 Input Analog Signal
(line output connected
parallel to input)
CH1 Analog
Signal
DSP engine OUT3
Output Analog Signal** CH2 Analog
Signal
DSP engine OUT4
Output Analog Signal**
CH1 CH 2
Signal is
not applied
to amplifer
Switches
Position
THRU
POST DSP
AES1-2
Digital Signal
DSP engine OUT3
Output Analog Signal**
DSP engine OUT4
Output Analog Signal**
Signal is
not applied
to amplifer
** The amplifiers have DSP module with four inputs (IN1-IN4). Only inputs IN1 and IN2
are used, inputs IN3 and IN4 are not used. Therefore, to receive a processed signal at the line
outputs, you need to enable signal routing to the outputs OUT3 and OUT4 from the inputs IN1
and/or IN2.
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.
5
Output Signal Input Signal Output Signal

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 GSd amplifier page).
User Interface
LCD display, LED indicators and controls (encoder and 2 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.
6

7
FUNCTIONAL FEATURES
Output Short-Circuit Protection
Individual per each channel. Protects the output stage of the power amplifier
against short-circuiting, as well as limits the output current when a maximum-level
sine signal is applied continuously to 2-Ohms loudspeaker.
Overload Protection
The double-stage overload protection system, independent for each channel, protects
the output stage and optimizes the quality sound under overload.
In the event of short overloads (for example, caused by a sharp decrease in
the complex load resistance), only the current protection of the output stage is
activated. It limits the output transistors current to safe level. Protect threshold
allows to give full output power shortly, even on case of very low load.
In case of a more continuous overload, the protection system activates the built-in Clip-
limiter, which reduces the level of the input signal.
DC Output Protection
With switchable power supply. Prevents DC Independent for each channel.
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.
High Frequency Protection
Independent for each channel. Prevents any damage to HF drivers as might be
caused by non-musical signals of powerful high frequency spectrum.
Should any powerful high frequency fluctuations occur on the output either
as a result of poor contact in the input cable connectors, or being send to the
amplifier’s input by any other device (such as a crossover or mixing console), the
protection system activates the built-in optoelectronic Clip-limiter to reduce the
input signal level. Thus the protection system effectively prevents any damage to
tweeters as might be caused by non-musical signals of powerful high frequency
spectrum.

8
Thermal Protection
Independent for each channel. Protects the amplifier’s output stage against
overheating.
The amplifier may stop functioning only in case of the fan breakdown or blocked
air flow. In this case upon reaching 85°С, the independent protection system disables
the respective channel of the amplifier. The CLIP LED goes on and the SIGNAL LED of
the affected channel goes off. The amplifier resumes its operation in the reverse order.
As soon as the amplifier cools down, the affected channels gradually regain their
amplification level up to the set value.
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
power-on 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.
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.