Overview
Martin Audio 4ch Class-D Installation Amplifer. 2500w/ch @ 4-Ohm, 1500w/ch @ 8-Ohm, 2500w @ 70/100v. 96kHz DSP. Analog and AES3 inputs.
Linea’s 44C Series of four channel amplifiers are optimised for use in installations. Combining massive power and peerless audio performance with unique DSP, the 44C Series also incorporates many features that ease it’s integration on to both new and legacy systems, the 44C Series represents an unmatched advancement in amplifier technology.
Sharing the same feature set and form factor as Linea's 88C Series of eight channel amplifiers the 44C Series is available in models that develop between 1,500Watts and 5,000 Watts per channel (up to 10,000 Watts for a bridged pair). Unusually these are not, ‘transient’, ‘burst’ or ‘peak’ power figures, they are the power levels that are delivered by all channels simultaneously even when driven with the same dense program material.
With Linea amplifiers there is no need to ration power between channels, you can use all the power you have paid for all the time. This has been independently verified.
Linea can do this because state of the art components and a finely optimised design results in an amplifier that is between 7% and 10% more efficient than any competitive product. This efficiency gain directly translates in to the generation of about half the wasted energy (heat) which is clearly significant. In addition to reducing energy costs high efficiency results in generous power reserves ensuring that pristine sound quality is maintained even under the most extreme conditions.
Uniquely, each channel can be configured to deliver its maximum power into 2, 4 or 8 Ohms (2 or 4 Ohms for the C20 model), nominal loads as well as 25V, 70V & 100V constant Voltage (CV) lines. This offers designers and integrators unparalleled flexibility and cost effectiveness.
Ethernet is used for remote control and monitoring while the tamper proof front panel allows easy verification of the operating status and signal levels. Control via Linea’s intuitive SE System Engineer PC application provides many convenient and time saving features such as very flexible management of presets, and Overlay grouping of Mutes, Gains, Delays and EQ across an entire system. Control from 3rd party systems is also possible via TCPIP, RS232 and RS485 while comprehensive relay and contact closure ports ensure that basic control can be achieved very easily.
The advanced 96kHz DSP is fully integrated into the product and provides an array of unique and genuinely useful features. Because all aspects of the DSP algorithms are designed and hand crafted in house by Linea, they are not available on products from any other manufacturer. For example, LIR linear phase crossover filters which are as easy to use as more conventional filter shapes, and have less latency than FIR filters. Also the powerful VX Limiter suite which sports Peak, RMS and Excursion limiting, as well as multiband limiting for passive 2-way enclosures.
Features
- Four channels of sonically pure Class D amplification
- Unique, precise, 96kHz digital signal processing
- Over‐designed switch mode power supply
- 85V to 240V Auto-sensing PSU
- 6,000 to 20,000 watts RMS total output
- Tamperproof front panel
- Ethernet network for system operation and monitoring
- Analogue, AES3 and optional Dante™ / AES67 digital network audio
- Powerful grouping & multi‐layer EQ
- Accepts 48kHz and 96kHz FIR files via System Engineer (certain models)
- Fully designed and engineered in house by Linea Research
- Manufactured in the UK
Specifications
General Specifications
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Number of output channels |
Four |
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Total power output, all channels driven |
20,000, 10,000 and 6,000 Watts RMS |
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Audio inputs |
4x Analogue, 2x AES3 and 4x Dante™ / AES67 (factory fitted option) |
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Digital Signal Processing |
High performance 96kHz DSP on all inputs and outputs |
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Control, monitoring and system status alarms |
Ethernet network, RS232 & RS485 Volt-free relay and contact closure ports. Heartbeat system health output |
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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 |
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System standby and wakeup |
Network command, audio detection & contact closure |
Power Output
|
Model |
44 series C20 |
44 series C10 |
44 series C06 |
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Power specification |
RMS output power per channel, all channels driven with continuous program material and a nominal ambient temperature of 40ºC / 105ºF |
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Crest Factor of 4 (12dB), 2-Ohm nominal load |
5,000W |
2,500W |
1,500W |
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Crest Factor of 2.8 (9dB), 4-Ohm nominal load |
3,000W |
2,500W |
1,500W |
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Crest Factor of 2 (6dB), 8-Ohm nominal load |
1,500W |
1,500W |
1,500W |
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Bridged, per channel pair, 4 Ohm load |
10,000W |
5,000W |
3,000W |
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25V line (CV) operation, Crest Factor 4 (12dB) |
1250W |
885W |
685W |
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70V line (CV) operation, Crest Factor 4 (12dB) |
3500W |
2,500W |
1,500W |
|
100V line (CV) operation, Crest Factor 4 (12dB) |
5,000W |
2,500W |
1,500W |
Audio Performance
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Amplifier topology |
Linea Research high performance Class D |
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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 typical |
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Gain (with all the DSP level controls set to 0dB) |
32dB |
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Frequency response, 4 Ohm load |
<7Hz to >30kHz, 4 Ohms, -2.5dB points |
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Total harmonic distortion, THD |
<0.05% typical, 1kHz signal, AES17 filter, 4 Ohm load |
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Inter-channel crosstalk, worst case combination |
better than -85dBr at 1kHz and -75dBr at 10kHz |
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Slew rate |
>60V per microsecond typical |
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Damping factor (Ref 8 Ohms) |
>800 at amplifier output (see Linea’s “Damping factor debunked” white paper) |
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Maximum analogue input level |
+20dBu |
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Analogue input sensitivity range for full output |
0dBu to +20dBu, continuously adjustable |
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Analogue input (four channels) |
Input 20k Ohm, electronically balanced, link directly connected to input |
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Analogue ground scheme |
AES48 standard compliant |
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AES3 input (two audio channels) |
Transformer isolated with unique active cable equalisation for extended range |
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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 |
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AES3 supported sampling rates |
24kHz to 192kHz (auto locking) |
Digital Signal Processing
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Resolution |
40 bit, Linea Research proprietary algorithms |
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Sample rate |
96kHz throughout |
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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 |
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Drive module output processing |
Source, delay, gain, Phase, Mute, crossover filters, VX limiters EQ: low shelf, 8x PEQ / band pass and shelving filters |
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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 |
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Unique high performance processing |
|
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Overlays |
Twelve additional independent overlays of EQ, Delay and Gain Flexible grouping for effective control of many amplifier channels in large systems |
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Class leading VX limiters |
See the ‘speaker protection systems’ section |
|
Hardman crossover filters |
Better out of band rejection than Linkwitz-Riley |
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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 |
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Internally stored energy |
>600 Joules |
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Nominal mains input voltage range |
85V to 240V, Power supply automatically detects voltage and configures accordingly |
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Mains input frequency range |
47Hz to 63Hz |
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Mains inrush current (max for <10ms) |
6A at 115V, 12A at 230V |
Protections Systems
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Under all circumstances the control and protection systems will endeavour to deliver the maximum power possible for a given set of conditions, 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 |
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Excessive power supply current or amplifier output current |
Sustained clipping prevention |
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Excessive temperature per sub system: PSU, amplifier and DSP |
DC offset protection |
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Mains voltage within acceptable limits |
Excessive HF energy (VHF) limiter |
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Internal power rails producing correct output |
|
|
Fans operating at correct speed |
VX audio output limiters |
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Vx provides a linear phase virtual crossover and two limiter paths on each output. This unique system delivers effective protection for systems that incorporate passive crossovers. |
|
|
Power distribution protection systems |
Vx Limit Multi-band peak limiter, two per output |
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Mains inrush current limiting for soft start and anti-surge |
Vx Max Multi-band overshoot limiter, two per output |
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Mains average current limiting for mains breaker management |
X-Max Driver excursion limiter |
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Randomised initialisation when remotely powered up |
T-Max Driver thermal limiter (long term power limiter) |
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Monitoring, measurements recorded against time |
Monitoring, device statistics and counters |
|
Supply current |
Number of power cycles counted |
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Supply voltage |
Number of mains brownout events counted |
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Thermal Capacity |
Fan speeds continuously monitored |
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Each driver current |
Fan under-speed events counted |
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Each driver impedance |
Various protection mute events counted |
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Protection limiting for each output |
Driver Impedance continuously monitored |
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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. |
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Physical
|
Cooling |
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 |
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Mains input connector |
Neutrik 32A Powercon™ |
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Dante Primary and Secondary |
2x Shielded RJ45 |
|
Ethernet network |
Shielded RJ45 |
|
RS232 and RS485 |
Phoenix™ pluggable terminal block (mating plug supplied) |
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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 |
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Enclosure, all models |
Standard 19” 2U (88mm), 357mm (14”) deep with handles and optional rear support |
|
Net Weight |
12.5kg (27.5 pounds). |
