The Keysight U8903B is a benchtop audio analyzer delivering high-precision measurements across analog and digital audio signals. It measures frequency response, distortion, noise, SNR, SINAD, IMD, THD, crosstalk, phase noise, and oscilloscope/spectrum analyzer-equivalent functions. The instrument achieves residual distortion below –110 dB, enabling evaluation of highly demanding audio devices with exceptional accuracy.
Technical Specifications
Measurement Range & Resolution
• Standard frequency range: DC or 10 Hz to 96 kHz
• Wide bandwidth option (N3431A): DC or 10 Hz to 1.5 MHz
• 24-bit digital resolution
• Two-million-point FFT (with wide bandwidth option)
• Configurable up to 8 simultaneous analog analyzer channels
• AC level range: < –120 dBFS to 0 dBFS
• Amplitude accuracy: ±0.03 dB overall
• Residual noise: Less than 1.3 μVrms (20 Hz to 20 kHz bandwidth)
Generator Performance
• Output frequency range: 5 Hz to 0.45 sampling rate (Fs)
• Residual THD+N: Less than –140 dB
• Output level: 0.6 mV to 6 V open circuit
• Output impedance: Switchable 50 ohms or 600 ohms
• Maximum output power: +17 dBm into 600-ohm load (at 50-ohm output impedance)
Analyzer Specifications
• Distortion and SINAD fundamental range: 20 Hz to 100 kHz
• Frequency measurement range: 20 Hz to 150 kHz
• AC level display ranges: 300.0 V, 30.00 V, 3.000 V, 0.3000 V, 30.00 mV, and finer scales
• DC level display ranges: 300.0 V, 48.00 V, 16.00 V, 4.000 V
• DSI logic level input: 1.2 V to 3.3 V variable
– Key Features
• Ultra-low residual distortion below –110 dB enables measurement of high-fidelity audio components
• Wide bandwidth option extends analysis to 1.5 MHz for Class D amplifiers and switching supplies
• Eight simultaneous analog channels support multichannel audio systems (5.1, 7.1 surround)
• Switchable 50-ohm/600-ohm output impedance adapts to professional and consumer equipment
– Typical Applications
• Consumer audio device evaluation (headphones, speakers, receivers)
• Professional audio equipment testing
• Class D amplifier analysis
• Switching power supply characterization
• Multichannel surround sound system verification
– Compatibility & Integration
Supports AES3/SPDIF (consumer and professional) and DSI (I²S, left justified, right justified, DSP) digital audio standards.
