The Brüel & Kjær 2690-0S-WH3345 Nexus Microphone Conditioner is a modular signal conditioning mainframe engineered for precision acoustic and vibration measurement in field and laboratory environments. The NEXUS architecture supports one to four independent input channels, accommodating condenser microphones, CCLD accelerometers, charge transducers, hydrophones, force transducers, and sound intensity probes within a single reconfigurable unit. This flexibility enables users to build custom measurement configurations without replacing hardware.
## Technical Specifications
**Input Architecture**
• Modular NEXUS mainframe; up to four independent channels per unit
• Condenser microphone inputs via 7-pin LEMO connectors with floating topology for EMI rejection
• CCLD and charge transducer support with current and voltage overload detection
• Sound intensity probe channels with IEC 61043 Class 1 and ANSI S1.9–1996 Class 1 compliance
**Microphone & Preamplifier Supply**
• Selectable polarization voltage: 0 V or 200 V
• Preamplifier supply: ±14 V or ±40 V (user-selectable)
• Current overload detection on all microphone channels
**CCLD Transducer Support**
• Constant current output: 4 mA or 10 mA
• 8 V DC tacho probe supply on TNC inner screen
**Signal Conditioning**
• Adjustable gain: -20 dB to 80 dB with automatic calibration storage
• Low-pass filters: 0.1, 1, 3, 10, 22.4, 30, 100 kHz at 40 dB/decade
• High-pass filters: 0.1, 1, 10, 20 Hz (20 Hz/80 dB/decade for 20 Hz)
• A-weighting filter standard; B-, C-, D-weighting available on request
• Intensity-specific 20 Hz/40 dB/decade high-pass filter
• Optional single and double integration filters; user-defined filters on request
**Overload Management**
Multi-stage detection: transducer current (CCLD and microphone), transducer voltage, common-mode input, signal, and common-mode output. Status indication via front-panel LEDs and RS-232 interface.
## Key Features
• Floating microphone inputs eliminate ground-loop interference
• Integrated reference generator capability
• Front-panel overload status indication with RS-232 reporting
• Tool-free module reconfiguration
## Typical Applications
Automotive testing, environmental acoustics, structural vibration analysis, sound intensity surveys, and general-purpose signal conditioning for transducer-based measurement systems.
## Compatibility & Integration
RS-232 interface for remote overload monitoring and system control. Accepts standard Brüel & Kjær NEXUS input modules and accessories.
