Linea’s 48M Series of eight output channel amplifiers are optimised for live sound applications. Offering a unique combination of massive power and peerless audio performance integrated with unique DSP, the 48M Series represents an unmatched advancement in amplifier technology.
Sharing the same feature set and form factor as Linea's 44M Series of four channel amplifiers the 48M Series is available in models that develop between 400Watts and 2,500 Watts per channel (up to 2,500 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.
Ethernet is used for remote control and monitoring while a front panel, optimised for use in challenging live environments, allows full local control of all features. Control via Linea’s intuitive Podware 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.
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.
Product Features
- *B-GRADE*
- Eight 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
- 3,000 to 20,000 watts RMS total output
- Full front panel user interface
- 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
Product Specifications
General
- Number of channels: Eight
- Total power output, all channels driven: 20,000, 10,000, 6,000 and 3,200 Watts RMS
- Audio inputs: 4x Analogue, 2x AES3 and 4x Dante™ / AES67 (factory fitted option)
- Digital Signal Processing: High performance DSP processing on all inputs and outputs
- Control, monitoring and system status alarms:
- Ethernet network
- Volt-free relay and contact closure port
- Power-save modes:
- Standby after user defined time, instant wake up on audio
- Deep ECO sleep after user defined time, wake up on command
- System sleep and wakeup: Front panel switch, network command and audio detection
Power Output
- Model: 48 Series M20
- Power specification: RMS output power per channel, all channels driven with continuous program material and a nominal ambient temperature of 40ºC / 105ºF
- Crest Factor of 4 (12dB), 2-Ohm nominal load: 1,500W
- Crest Factor of 2.8 (9dB), 4-Ohm nominal load: 2,500W
- Crest Factor of 2 (6dB), 8-Ohm nominal load: 1,500W
- Bridged per channel pair, 4 or 8-Ohm load: 3,000W / 5,000W
- 100V line (CV) operation, Crest Factor 4 (12dB): 2,500W
- 70V line operation, Crest Factor 4: 1,937W
- 25V line operation, Crest Factor 4: 625W
Audio Performance
- Amplifier topology: Linea Research high performance Class D
- Amplifier modulation scheme: Low feedback, multiple loop, with feed-forward error correction
- Dynamic range to amplifier output:
- Analogue input, better than 113dBA typical
- AES / Dante™ input, better than 114dBA typical
- Gain (with all 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
- Maximum analogue input level: +20dBu
- Analogue input sensitivity range for full output: 0dBu to +20dBu, continuously adjustable
- Analogue input (four channels): Input 20k Ohm, electronically balanced, link directly connected to input
- Analogue 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
- 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 and 12A at 230V
Physical
- Cooling: Dual vari-speed fans, front to back airflow. Washable, tool less change filter media.
- Analogue IN and LINK: 4x female and 4x male Neutrik™ XLR
- AES3 dual channel IN and LINK: 1x female and 1x male Neutrik™ XLR
- Amplifiers output: 4x Neutrik Speakon™ NL4 connectors
- Mains input connector: Neutrik 32A Powercon™
- Dante Primary and Secondary: 2x Shielded RJ45
- Relay output & contact closure inputs: Phoenix™ pluggable terminal block (supplied)
- Front panel display (backlit): Graphical, high contrast, daylight visible
- Front panel encoders: Two, indented, velocity sensitive
- Front panel push buttons: Large, tactile, illuminated
- LED indicators: Bright, easily differentiated
- Enclosure: Standard 19” 2U (88mm), 357mm (14”) deep with handles and optional rear support
- Net Weight: 12.5kg (27.5 pounds)
