12
C Series
Quick Start Guide
13
Introduction
Welcome
Thank you for choosing Lab Gruppen C Series power amplifiers for your sound
reinforcement system installation. We are confident that you will be very pleased
with the performance, configuratio
n flexibility, reliability, and long-term
durability offered by the C Series products.
This manual provides a comprehensive guide to the features and functionality
of C Series model C 88:4, C 68:4, C 48:4, C 28:4 and C 16:4 amplifiers. Please read
through it in its entirely to become fully acquainted with the many configuration
options and multiple layers of protection circuitry.
To facilitate timely installation and use of this C Series product, we have included
a Quick Guide Overview (section 4). This brief summary, in conjunction with
Installation (section 3), contains the basic information needed to safely install the
amplifier and place it in service. However, we highly recommend reading through
this manual in its entirety, beginning with Main Features and Technologies and
continuing through Operation and Performance. As you become thoroughly
familiar with all aspects of operation, you may learn of features or options that
will affect your choices on amplifier modes or loudspeaker system configuration.
Lab Gruppen C Series power amplifiers are designed and built specifically for the
unique demands of permanent installation applications. C Series amplifiers offer
the optimum combination of high-quality audio reproduction, flexible features,
ease of installation, and 100% reliability in normal use.
By packing four or eight channels of reconfigurable power amplification into
a 2U chassis, the C Series achieves unprecedented power and channel density.
The benefits of compact dimensions include reduced rack space requirements
and minimal heat build-up. The flexible output stages enable each amplifier
channel to be set for either low impedance or constant voltage (70 V / 100 V)
mode. NomadLink, an easy-to-use network for monitoring and control,
is implemented as a standard feature on all C Series amplifiers.
Although C Series features and facilities are tailored to installation applications,
at the heart of each amplifier is the same advanced technology that has made
Lab Gruppen the benchmark of quality for touring concert systems: exceptional
sonic performance, rugged construction, proven reliability, and protection
features that anticipate every unwelcome possibility.
NOTE:
This manual is shipped with C Series amplifi er models C 88:4, C 68:4,
C 48:4, C 28:4 and C 16:4. All references to “C Series” in this manual apply to all
four of these models. A different manual is shipped with models C 20:8X, C 10:8X,
C 10:4X and C 5:4X. References to C Series in this document may or may not apply
to these C…X models.
Main Features
Your new C Series amplifier incorporates a number of sophisticated technologies
– many of them proprietary to Lab Gruppen – that are provided to ensure the
best possible performance and many years of reliable operation. Familiarizing
yourself with these technologies will prove invaluable in setting up and
optimizing your loudspeaker system.
Class TD amplifier and Regulated Switch Mode
Power Supply (R.SMPS)
Lab Gruppen’s patented Class TD technology combines the exceptional efficiency
of a Class D amplifier with the high sonic quality associated with Class B
designs. Class TD also incorporates the same basic concepts behind Class H
designs, but here they are refined and pushed to a higher level to achieve much
greater efficiency.
The Class TD output sections work in concert with Lab Gruppen’s unique,
regulated switch-mode power supply (R.SMPS) to create a superior overall power
amplifier topology. This ensures stable, full output power over an extremely
wide range of mains voltage levels. Sagging or fluctuating mains voltage will not
affect the power output delivered to the loudspeakers.
Amplifier gain
For greater flexibility in system integration, C Series amplifiers allow gain
adjustment from +23 dB to +44 dB in 3 dB steps. This feature accommodates
any combination of input device and loudspeaker type. For example, if the input
signal is weak, the gain can be boosted to maintain maximum power output
while avoiding a poor signal- to-noise ratio. This gain adjustment feature makes
it easier to achieve an optimal balance between headroom and noise floor.
Voltage Peak Limiter (VPL)
The Voltage Peak Limiter (VPL) feature allows user adjustments that determine
maximum voltage output, thus matching the amplifier to the connected speaker
load. Whether the connected load is low impedance (2 to 16 ohms) or high
impedance (70 V / 100 V), the VPL feature can be set to ensure that neither
temperature nor current limitations are exceeded before reaching the desired
voltage threshold.
Protection and performance optimization
Appropriate and reliable power amplification is vital to any audio system.
Inadequate or faulty power amplification could cause damage to the
loudspeakers, or in some cases to the power amplifiers themselves. To prevent
any damage or costly service interruptions, C Series amplifiers offer advanced
features to protect both internal circuits and any connected loads. These features
even protect the mains fuse that, in extreme cases, could be overloaded.
Following are short descriptions of standard built-in C Series protection features:
•
CPL
(Current Peak Limiter) ensures that the amplifier’s output does not exceed
the safe current handling parameters of amplifier components.
•
Temperature protection
ensures that the amplifier will not be damaged by
exceeding thermal limits.
•
PAL
(Power Average Limiter) limits the maximum average power consumption
according to the power supply and mains-breaker capabilities.
•
VHF
(Very High Frequency) protection circuits mute the output of the
amplifier when nondynamic continuous signals above 10 kHz are detected.
•
DC protection
ensures destructive DC signals will not appear at the amplifier
outputs. If such conditions occur an internal fuse opens and fault indication
is displayed.
•
Low-impedance
(short circuit) protection provides a fault warning indication
and shuts down the output stage when, for example, an input signal is present
and a malfunctioning cable or driver is short circuiting the output.
•
High-impedance
warning reports an alert when, at the same time, output
signal is high and no current draw is measured. This situation might occur
when no speakers are connected, or when a driver is blown.
•
Low inrush current
ensures that the mains breaker will not trip when
several power amplifiers are turned on simultaneously.
NomadLink / Ethernet control and
monitoring network
The NomadLink network allows easy setup and control of C Series power
amplifiers and other devices. The patented network topology allows automatic
detection and addressing of multiple amplifiers, and is controlled from a PC
via an NLB 60E NomadLink Bridge & Network Controller using standard TCP/IP
communication. Phantom powering through the network cables allows the
software to detect devices that are not currently turned on or connected to the
mains. This ensures very high reliability and redundancy levels while allowing
connected amplifiers to remain on standby with no power consumption.
Cable connections can be daisy-chained for easier system setup. This also reduces
total component costs, simplifies installation, and makes daily operation more
convenient. There is no need to create a star topology using many switches as
with, for example, an Ethernet system. Individual amplifier addresses do not
need to be manually entered: you will automatically know where an individual
amplifier resides in the network.
A daisy chain network-loop, in combination with the automatic addressing
of devices, enables Lab Gruppen’s proprietary DeviceControl software to
automatically create a precise picture of all connected devices and their relative
position in the chain. By quickly creating a clear overview of the entire system
configuration, DeviceControl provides flexible control over very large amplifier
systems. Set-up time is minimized, and critical information is readily available for
monitoring performance and solving problems during operation.
Via NomadLink, you can simultaneously monitor all metering data as well
as any fault or warning indications. NomadLink also allows you to remotely
control power on and power off, as well as engage Mute and Solo functions on
individual channels.
NOTE:
If the amplifier malfunctions due to dirty dust filters, any required repairs
are not covered by the warranty.
Installation
Unpacking
Carefully open the shipping carton and check for any noticeable damage. Every
Lab Gruppen amplifier is tested and inspected before leaving the factory and
should arrive in perfect condition. If any damage is discovered, please notify the
shipping company immediately. Only the consignee may institute a claim with
the carrier for damage incurred during shipping. Save the carton and packing
materials for the carrier’s inspection. Should you ever need to ship the amplifier,
always use the original packaging materials.
Mounting
The amplifier is two rack units high (2U) and will fit into a standard EIA 19" rack.
The depth is 343 mm (13.5"). The weight is approximately 8.5 kg (18.75 lbs.)
depending on model type.
Free airflow from front-to-rear of the amplifier must be possible. Therefore, no
doors or rack-lids should be mounted in front of or behind the amplifiers.
Amplifiers may be stacked directly on top of each other. There is no need for
spacing in between units, though this might enable more convenient installation
of cabling on the rear panel.
Cooling
The amplifier uses a forced-air cooling system with air flow from front to rear,
maintaining a low operating temperature within defined limits. Front-to-rear
airflow is preferred as cooler air is present at the front in nearly all applications.
(This allows higher continuous power levels without encountering thermal
problems.) Never attempt to reverse the airflow. The amplifier modules require a
pressure chamber between the fans and heat sink, and this effect functions only
in one direction.
Make sure that there is an adequate air supply in front of the amplifier, and that
the rear of the amplifier has sufficient space to allow the exhaust to escape. If
the amplifier is rack-mounted, do not use covers or doors on the front or rear of
the rack.
Should a heat sink overheat, the temperature sensing circuits will mute the
overheating channel. If the power supply overheats, another sensing circuit
will mute all output channels until the power supply cools to safe operating
temperature. An early warning before shut down will be indicated on the front
panel LEDs, and a warning will be sent through the NomadLink network.
Always make sure that the dust-filters behind the detachable front panel are
clean to ensure maximum possible airflow.
NOTE:
If the amplifier malfunctions due to dirty dust filters, any required repairs
are not covered by the warranty.
To calculate the maximum heat emission value when installing the amplifiers
in rooms with an air-conditioning system, please refer to the Current Draw and
Thermal Emissions specifications provided in the Appendix (section 6.4xxx).
Operating Voltage
The label placed to the right of the mains cable on the rear of the
amplifier indicates the AC mains voltage for which the amplifier is
wired and approved: 115 V or 230 V. Connect the power cable only to
the AC source type referred to on the label. The warranty will not cover damage
caused by connecting to an incorrect type of AC mains.
Lab Gruppen switch-mode amplifiers use primary switching. Because the mains
power is rectified directly in front of the transformer, the amplifier is insensitive
to mains frequency. It may be connected to 50 or 60 Hz sources, and actually will
operate on line frequencies from DC to 400 Hz.
If the power plug mounted at the factory is not appropriate for your country,
it can be removed and the proper connector wired in its place as follows:
BLACK or BROWN
LIVE
WHITE or BLUE
NEUTRAL
GREEN or GREEN/YELLOW
EARTH (GROUND)
If you are not 100% confident of your competence to replace the
mains plug, engage qualified personnel to do the job.
Once a suitable AC supply is connected, the amplifier can be turned on using the
front-panel power switch. The amplifier then goes through a soft-start sequence
as it self-checks its circuits. The fans will blow at high speed before dropping to
idle, and the “power” LED will illuminate.
Inrush power is controlled and limited during “soft start”, enabling multiple
amplifiers to be powered up simultaneously.
Grounding
There is no ground lift switch or terminal on the C Series amplifiers. The signal
ground is always floating, via a resistor, to chassis and therefore the grounding
system is automatic.
In the interests of safety, never disconnect the earth (ground) pin on the AC
power cord.
Use balanced input connections to avoid hum and interference.