NEXO’s New NXAMP Powered TDcontrollers

17 September 2007 — NEXO’s new NXAMP powered TDcontrollers represent a major breakthrough in the field of high-powered amplification for both fixed and mobile applications. A far more complex device than just a bundled power amplifier and loudspeaker controller, the NXAMPS offer cost-effective integration of command, control, protection and amplification of all NEXO loudspeaker systems.

Not only is the NXAMP lighter and less space-consuming than conventional amplifier-processor systems, but it also eliminates several stages of A/D conversion. Combining practical advantages with superior sonic performance, the NXAMP specifications place it among the industry’s most powerful amplifiers, presenting very high power with low load drive.

More than two years of research have yielded significant DSP innovations which allow multiple voltage/current/temperature sense lines from the amplifier’s output, to protect both the amplifier and power supply.

NXAMP DSP protection includes:

• Power-on protection (smooth start-up with in-rush limitation)
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  Power-off protection (clean shut-down procedure)
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  Peak Voltage limiter (clip limiting)
  
  
• Peak Current limiter
  
  
• VHF protection
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  Integrated current limiter
  
  
• DC offset protection
  
  
• Short circuit protection
  
  
• Fan speed control
• Power Amp overheat protection
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  SMPS overheat protection
  
  
• SMPS fault protection
• Power cable monitoring

NXAMP power supplies are full resonance types with half bridge converters. This exceptional design minimizes noise via (Zero Crossing Switch (ZCS) technology. NXAMP4x4 employs four times the structure of a monaural amplifier to present very high power with low load drive.

This requires four converters, four transformers and of course four power supplies. In addition, on both NXAMP models, two converters work synchronize the opposite phase, thus cancelling noise. The benefits include unrivalled sonic performance and low EMC

Both NXAMP amplifiers employ YAMAHA’s EEEngine technology. This technology offers the sonic purity of conventional class AB, but with a heat dissipation equalling class D technology. In fact, NXAMP rails constantly follow the output signal needs, minimizing the required headroom (and wasted energy).

NXAMP signal processing is identical on both models, and is derived from the NX242 TDcontroller. Processing power has been increased on both CPU and DSP side. NXAMP uses twin Freescale (formerly Motorola) DSPs, with a total processing power which is 3.5 times the processing power of an NX242 fitted with an ES-4 NXtension board.

Amplifier output is now sensed in both voltage and current and 24bit converters execute these measurements. The latest generation audio converters provide enhanced dynamic range with low latency (500us) analog input to output, in FLAT mode.

The rear panel expansion slot allows easy addition of an ES100 EtherSound board. This new generation of EtherSound firmware offers device-to-device communication and powerful new functions.

Power Specifications:

• NXAMP4x4
• Number of amplifier channels 4 x channels, 2 by 2 bridgeable
• Max. output voltage (no load) 4 x 200 Volts
• Max. output power (8 ohms) 4 x 1900W
• Max. output power (4 ohms) 4 x 3300W
• Max. output power (2 ohms) 4 x 4000W

• NXAMP4x1
• Number of amplifier channels 4 x channels, 2 by 2 bridgeable
• Max. output voltage (no load) 4 x 105 Volts
• Max. output power (8 ohms) 4 x 600W
• Max. output power (4 ohms) 4 x 900W
• Max. output power (2 ohms) 4 x 1300W