Lab Gruppen C 68:4

Lab Gruppen's C 68:4 delivers 4 × 1700 W and is 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 100/70 V loudspeakers.  VPL works in combination with adjustable input gain to achieve maximum headroom regardless of input levels or output impedances.

Every C Series 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 managed efficiently under network control.

For more information, please consult the attached sheet (under "Documents")

Specifications:

• Number of channels: 4
• Peak total output all channels driven: 6800 W
• Peak output voltage per channel: 141 V
• Max. output current per channel: 24.5 Arms
• Dimensions: 19" W x 13.5" D x 2RU H (483 x 88 x 343 mm)
• Weight: 26.4 lbs. (12 kg)
• Finish: Black painted steel chassis with gray painted steel front
• Approvals: CE, ANSI/UL 60065 (ETL), CSA C22.2 NO. 60065, FCC

Max. Output Power per Channel (all channels driven):

• 16 Ohms: 650 W
• 8 Ohms: 1200 W
• 4 Ohms: 1700 W
• 2 Ohms: 1200 W
• Hi-Z: 1600 W (70 Vrms/100 V peak)

Max. Output Power Bridged per Channel:

• 16 Ohms: 2400 W
• 8 Ohms: 3400 W
• 4 Ohms: 2400 W
• 2 Ohms: n.r.
• Hi-Z: 3200 W (140 Vrms/200 V peak)

Performance with Gain: 32 dB and VPL: 100 V

• THD 20 Hz - 20 kHz for 1 W: <0.1%
• THD at 1 kHz and 1dB 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.: 141, 118, 100, 85, 71, 59, 50, 42 V
• VPL, selectable when bridged: 282, 236, 200, 170, 142, 118, 100, 84V 
• Voltage Peak Limiter mode (per ch.): Hard / Soft

Gain and Level:

• Amplifier gain selectable (all channels) – 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
• High pass filter: Fixed at 35 Hz, switchable per channel
• NomadLink® network: On board, 2 x RJ45 connectors, IN and OUT
• 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); Power on
• Per channel: Signal present / High-impedance; -10 dB & -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): Yes
• Soft start / Inrush current draw: Yes / max. 5 A
• Mains connector: 230 V CE: 16 A, CEE7; 115 V ETL: 20 A / NEMA 5-20P

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.
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.

TMGR# C68:4