• 44C series

4 Channel Advanced Contractor Amplifiers
Linea Research 4 channel
amplifiers present a unique
combination of power and audio
performance combining
advanced DSP and network
control with many contractor
friendly features. Sharing thesame feature set and form factor
as the 88C series amplifiers and•
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available in models developing
between 1,500 Watts and 5,000
Watts per channel (or 10,000
Watts for a bridged pair).
Uniquely each channel can be
optimised to deliver its power
into 2, 4 or 8 Ohm nominal loads
as well as 25V, 70V & 100V
constant Voltage (CV) lines. This

offers designers and integrators
unparalleled flexibility and costeffectiveness. Using state of theart components and a finely
optimised design results ingenerous power reserves that
ensure pristine sound quality is
maintained even under the mostextreme conditions.

Four channels of sonically pure Class D amplification
Power per channel, all channels driven
Unique, precise, 96kHz digital signal processing
Model
44C20
44C10
44C06
Over-designed switch mode power supply
2 Ohm
5,000
2,500
1,500
Tamper-proof front panel
4 Ohm
3,000
2,5001,500
Contractor friendly connectors
8 Ohm
1,500
1,500
1,500
Contact closure control ports and relay status outputs
Ethernet, RS232 and RS485 for system control and monitoring
Analogue, AES3 and Dante™ / AES67 audio inputs
Powerful grouping and multi-layer EQ
Accepts 48kHz and 96kHz FIR files via System Engineer
Fully designed and engineered by Linea’s in-house development team
Manufactured, tested, and supported entirely in the UK

General Specifications
Number of output channels

Four

Total power output, all channels driven

20,000, 10,000 and 6,000 Watts RMS

Audio inputs

4x Analogue, 2x AES3 and 4x Dante™ / AES67 (factory fitted option)

Digital Signal Processing

High performance 96kHz DSP on all inputs and outputs

Control, monitoring and system status alarms

Ethernet network, RS232 & RS485
Volt-free relay and contact closure ports. Heartbeat system health output

Power-save modes

Standby after user defined time with fast wake up on audio
Deep ECO sleep after user defined time with wake up on command

System standby and wakeup

Network command, audio detection & contact closure

Power Output
Model44C2044C1044C06

Power specification

RMS output power per channel, all channels driven with continuous program material
and a nominal ambient temperature of 40°C / 105°F

Crest Factor of 4 (12dB), 2 Ohm nominal load

5,000W

2,500W

1,500W

Crest Factor of 2.8 (9dB), 4 Ohm nominal load

3,000W

2,500W

1,500W

Crest Factor of 2 (6dB), 8 Ohm nominal load

1,500W

1,500W

1,500W

Bridged, per channel pair, 4 Ohm load

10,000W

5,000W

3,000W

25V line (CV) operation, Crest Factor 4 (12dB)

1,250W

885W

685W

70V line (CV) operation, Crest Factor 4 (12dB)

3,500W

2,500W

1,500W

100V line (CV) operation, Crest Factor 4 (12dB)

5,000W

2,500W

1,500W

Audio Performance
Amplifier topology

Linea Research high performance Class D

Amplifier modulation scheme

Low feedback, multiple loop, with feed-forward error correction

Dynamic range
Measured relative to the amplifier output

Analogue input, better than 113dBA typical
AES / Dante™ input, better than 114dBA typicalGain (with all the DSP level controls set to 0dB)

32dB

Frequency response, 4 Ohm load

<7Hz to >30kHz, 4 Ohms, -2.5dB points

Total harmonic distortion, THD<0.05% typical, 1kHz signal, AES17 filter, 4 Ohm load

Inter-channel crosstalk, worst case combination

Better than -85dBr at 1kHz and -75dBr at 10kHz

Slew rate>60V per microsecond typicalDamping factor (Ref 8 Ohms)>800 at amplifier output (see Linea’s “Damping factor debunked” white paper)

Maximum analogue input level+20dBuAnalogue input sensitivity range for full output

0dBu to +20dBu, continuously adjustable

Analogue input (four channels)

Input 20k Ohm, electronically balanced, link directly connected to inputAnalogue ground scheme

AES48 standard compliant

AES3 input (two audio channels)

Transformer isolated with unique active cable equalisation for extended range

AES3 link (two audio channels)

Active AES3 signal regeneration. Automatic direct bypass to the AES3 input ensuring
the audio signal will still flow even when the amplifier is powered down

AES3 supported sampling rates

24kHz to 192kHz (auto locking)Digital Signal Processing
Resolution

40 bit, Linea Research proprietary algorithms

Sample rate

96kHz throughout

Physical inputs to DSP drive modules

4x Analogue, 2x AES & 4x Dante™ inputs can be routed to four DSP drive modules

Drive module input processing

Input signal routing, Delay, Gain, HPF, Phase, Mute
EQ: 2x low shelf, 6x PEQ / band pass and FIR shelving filters

Drive module output processing

Source, Delay, Gain, Phase, Mute, Crossover filters, VX limiters
EQ: low shelf, 8x PEQ / band pass and shelving filters / 768 tap FIR

Preset management

10 snapshots for device wide setup, 50 presets for loudspeaker settings
Presets can be recalled to sets of outputs or individual outputs as required

Unique high-performance processing
Overlays

Twelve additional independent overlays of EQ, Delay and Gain
Flexible grouping for effective control of many amplifier channels in large systems

Class leading VX limiters

See the ‘speaker protection systems’ section

Hardman crossover filters

Better out of band rejection than Linkwitz-Riley

LIR crossover filters

Unique Linear Phase alignments without the compromises of FIR filters

Power Supply
Topology (main power supply)

Linea Research high performance Series Resonant

Topology (auxiliary and standby supplies)

Low quiescent Eco-Flyback

Internally stored energy>600 Joules

Nominal mains input voltage range

85V to 240V, Power supply automatically detects voltage and configures accordingly

Mains input frequency range

47Hz to 63Hz

Mains inrush current (max for <10ms)

6A at 115V, 12A at 230V

Protections Systems
Under all circumstances the control and protection systems will endeavour to deliver the maximum power possible for a given set ofconditions, applying limiters only in extreme circumstances. Muting will only occur when a dangerous situation is detected, normal
operation automatically resuming when the condition clears.
System protection

Speaker protection

Excessive power supply current or amplifier output current

Sustained clipping prevention

Excessive temperature per sub system: PSU, amplifier and DSP

DC offset protection

Mains voltage within acceptable limits

Excessive HF energy (VHF) limiter

Internal power rails producing correct output
Fans operating at correct speed

Power distribution protection systems

VX audio output limiters
Vx provides a linear phase virtual crossover and two limiter paths oneach output. This unique system delivers effective protection forsystems that incorporate passive crossovers.
Vx Limit Multiband peak limiter, two per output

Mains inrush current limiting for soft start and anti-surge

Vx MaxMains average current limiting for mains breaker management

X-Max

Driver excursion limiter

Randomised initialisation when remotely powered up

T-Max

Driver thermal limiter (long term power limiter)

Monitoring, measurements recorded against time

Monitoring, device statistics and counters

Supply current

Number of power cycles counted

Supply voltage

Number of mains brownout events counted

Thermal Capacity

Fan speeds continuously monitored

Each driver current

Fan under-speed events counted

Each driver impedance

Various protection mute events counted

Protection limiting for each output

Driver Impedance continuously monitored

Multiband overshoot limiter, two per output

An inbuilt notification system is provided that indicates problems to remote devices either via the network or the Volt-free changeover
relay contacts accessible on the rear panel.

PhysicalCooling

Dual vari-speed fans, front to back airflow. Washable, tool-less change filter media.

Analogue IN and LINK

Phoenix™ pluggable terminal block (mating plug supplied)

AES3 IN and LINK

Phoenix™ pluggable terminal block (mating plug supplied)

Amplifier output

Neutrik Speakon™ NL4 connectors

Mains input connector

Neutrik 32A Powercon™

Dante™ Primary and Secondary

2x Shielded RJ45

Ethernet network

Shielded RJ45

RS232 and RS485

Phoenix™ pluggable terminal block (mating plug supplied)

Relay, ‘heatbeat’ outputs

Phoenix™ pluggable terminal block (mating plug supplied)

Contact closure inputs

Phoenix™ pluggable terminal block (mating plug supplied)

Front panel LED indicators

Per channel - Input level, output level & status

Enclosure, all models

Standard 19” 2U (88mm), 357mm (14”) deep with handles and optional rear support

Net Weight

12.5kg (27.5 Lbs)

For more information about the 44C series amplifiers or Linea’s other high-performance audio products,
please contact us or your local dealer.
Linea Research Ltd
Units 1 & 2 Aylesford Court
Works Road
Letchworth Garden City
Herts, U.K.
SG6 1LP
Tel: +44(0)1462 893 500
Tel: +1 949 436 4745 (USA Office)
Email: info@linea-research.co.uk

www.linea-research.co.uk

E&OE AUGUST2019 V1.3