Lab.gruppen C 88:4 Instruction manual

Unprecedented power density –•Total output of 8800 W
(2 ohms) in 2U
Four channels –•All channels bridgeable for 2- or 3-channel
configurations
Lo-Z or Hi-Z (70 V / 100 V) –•Selectable per channel, normal or
bridged
Patented Class TD•®amplifier topology
Voltage Peak Limiter (VPL) –•Configurable per channel to
optimize each output for connected loads
Phoenix-type input connectors•
Screw terminal output connectors•
Comprehensive protection and warning –•Excessive output
current, DC, high temperature, very high frequency (VHF), short
circuit, open load, mains fuse protection, and soft start
Efficient and uniform Intercooler•®cooling
NomadLink•®network ready
An Installation Amplifier without Compromise
Installed or on tour, uncompromising quality begins with supe-
rior sound. Over the past decade, the sound of Lab.gruppen ampli-
fiers has earned praise from renowned FOH engineers and owners
of the world’s premier sound rental companies. At the core of
the C Series high-power* model’s tight and transparent sound is
patented Class TD technology. As a proprietary implementation of
tracking Class D, Class TD approaches the exceptional efficiency of
Class D while retaining the superior sonic quality of the best Class B
output stages.
A Regulated Switch Mode Power Supply™(R.SMPS) contributes to
the remarkable efficiency of the C Series high-power models, while at
the same time providing stable operation even with wide fluctuations
in mains voltage. R.SMPS also works in conjunction with Class TD to
give extraordinary power density. More channels with more power
are condensed into a smaller package, allowing C Series amplifiers to
minimize rack space requirements and reduce installation costs.
Extreme power density demands efficient cooling, and here
Lab.gruppen’s Intercooler proves remarkably effective. Thousands of
small copper cooling fins dissipate heat, and all output devices are
mounted on one row perpendicular to airflow for uniform cooling.
C Series amplifiers are uniquely capable of adapting to a wide
variety of demanding load conditions. Each channel has an
individually configurable Voltage Peak Limiter (VPL), which allows
the output to be optimized for any loudspeaker load – whether one
massive subwoofer or a series of small 100 V loudspeakers. VPL
works in combination with adjustable input gain to achieve maximum
headroom regardless of input levels or output impedances.
To assure reliability, and minimize service interruptions, C Series
amplifiers offer comprehensive warning and protection features.
Whenever faulty wiring, improper use, or extreme ambient tempera-
tures threaten trouble, a C Series amplifier gives clear and accurate
warning indications. Protection measures are inserted only when
dangerous thresholds are passed. Conditions are re-checked at
six-second intervals, and normal operation resumes when measure-
ments return to nominal.
Every C Series amplifier is ready for the NomadLink network right out
of the box. With NomadLink, key amplifier parameters are displayed
via DeviceControl software, and remote control of channel mutes
and power on/off is under network control. (NomadLink requires the
separate NLB 60E NomadLink Bridge & Network Controller.)
Auditoriums•
Performing Arts Centers•
Convention Centers•
Stadiums and Arenas•
Theme Parks•
Hotels•
Houses of Worship•
Restaurants•
Clubs•
Educational Establishments•
Boardrooms•
Museums•
Offices•
Shopping Malls•
Transportation Facilities•
Applications
* C Series high-power models are:
C 88:4, C 68:4, C 48:4, C 24:4 and C 16:4
C 88:4
Technical Data
C Series: Dedicated Installation Amplifiers

Lab.gruppen ab •Sweden
internationaL contact • [e-mail] | uS contact • [e-mail]
www.labgruppen.com
Item no. TDS-C884
General
Number of channels 4
Peak total output all channels driven 8800 W
Peak output voltage per channel 141 V
Max. output current per channel 35.5 Arms
Max. Output Power 16 ohms 8 ohms 4 ohms 2 ohms 70 Vrms/100 Vrms peak
Per ch. (all ch.’s driven) 625 W 1250 W 2100 W 2200 W 2200 W
Bridged per ch. 2500 W 4200 W 4600 W n.r 4) n.r 4)
Performance with Gain: 35 dB and VPL: 141 V
THD 20 Hz - 20 kHz for 1 W <0.1%
THD at 1 kHz and 1 dB below clipping <0.05%
Signal To Noise Ratio >112 dBA
Channel separation (Crosstalk) at 1 kHz >70 dB
Frequency response (1 W into 8 ohms) +0/-3 dB 6.8 Hz - 34.2 kHz
Input impedance 20 kOhm
Input Common Mode Rejection, CMR 50 dB
Output impedance @ 100 Hz 30 mOhm
Voltage Peak Limiter (VPL), max. peak output
VPL, selectable per ch. 3) 141, 118, 100, 85, 71, 59, 50, 42 V
VPL, when bridged 3) 1) 282, 236, 200, 170, 142, 118, 100, 84 V
Voltage Peak Limiter mode (per ch.) Hard / Soft
Gain and Level
Amplifier gain selectable (all channels) 1)
– rear-panel switches 23, 26, 29, 32, 35, 38, 41, 44 dB
Default gain 35 dB
Level adjustment (per ch.) Front-panel potentiometer, 21 position detented from -inf to 0 dB, hidden behind security panel/dust filter grille
Connectors and switches
Input connectors (per ch.) 3-pin Phoenix, electronically balanced
Output connectors (per ch.) Barrier strip 2-pole screw terminals
Output bridge mode A+B and/or C+D, inputs A and C are input source
NomadLink network On board, 2 x RJ45 connectors
Intelligent fans (on/off) Yes, depending on presence of output signal
Power on/off and Remote enable on/off Individual switches on front-panel
Cooling Two fans, front-to-rear airflow, temperature controlled speed
Front-panel indicators
Common NomadLink Network; Power Average Limiter (PAL) 2); Power on
Per channel Signal present / High-impedance; -10 dB and -4 dB output signal; Voltage Peak Limiter (VPL); Current Peak Limiter (CPL);
Very High Frequency (VHF); High Temperature; Fault; Mute
Power
Operating voltage, 230 V / 115 V nominal 130 -265 / 65-135 V
Minimum power-up voltage, 230 V / 115 V 171 V / 85 V
Power Average Limiter (PAL) 2) Yes
Soft start / Inrush Current Draw Yes / max. 5 A
Mains connector 230 V CE: 16 A, CEE7; 115 V ETL: 30 A Twist Lock
Dimensions (W/H/D) W: 483 mm (19”), H: 88 mm (2 U), D: 343 mm (13.5”)
Weight 12 kg (26.4 lbs.)
Finish Black painted steel chassis with gray painted steel front
Approvals CE, ANSI/UL 60065 (ETL), CSA C22.2 NO. 60065, FCC
Note 1): Automatic -6 dB gain compensation when bridging channels. Ch.’s A+B and/or C+D, can be bridged individually.
Note 2): PAL can reduce the maximum output power to keep the power supply operating safely, and/or to prevent excessive current draw tripping the mains breaker.
Refer to Operation Manual.
Note 3): For sine waves, peak voltage output values translate to Vrms with the formula V/1.41 = Vrms. E.g. 100 V peak equals app. 70 Vrms.
Hence, outputs can be set for high-impedance loads without requiring a transformer.
Note 4): Regarding n.r. (not recommended) notes: The amplifier will be fully operational in bridge-mode into 2 ohm and high impedance (Hi-Z) loads, but due to physical constraints
in the construction, the max. output power will not be significanty higher than running individual channels and therefore this mode of operation is not recommended.
All specifications are subject to change without notice.
Specifications C 88:4