Audio analyser delivers speed, accuracy improvements

With a typical residual THD+N of -120 dB (conservatively specified at -117 dB), the two analogue channels of the APx555 boast the lowest noise and distortion of any audio analyser, allowing the most sensitive measurements to be made with assurance. This performance is coupled with 1 MHz bandwidth (mono) and FFT resolution of 1.2 million points.

The generator is capable of producing low distortion sine wave signals up to 204 kHz, at high-level amplitudes up to 26 Vrms. The analyser offers audio developers previously unachievable insight into the behaviour of their designs, unimpaired by noise or artefacts from the test system. In conjunction with the APx555 introduction, Audio Precision is releasing the new APx500 v4.0 software, which provides a multi-mode user interface for the entire APx family of analysers.

Developed with system flexibility in mind, the software allows easy switching between Sequence Mode – the fast and efficient menu of measurements with which APx users worldwide are familiar – and Bench Mode,  a SYS-2700 series-inspired approach that delivers real-time feedback of any selected parameters, including waveform scope, FFT spectrum, levels, frequency, THD+N, and more. Engineers may choose the mode that best suits their needs with a click of a mouse button.

“Bench Mode offers more visibility into real-time behaviours.” says Eric Cline, Engineering Technician at Analog Devices. “Being able to see everything at once is a huge deal - distortion, noise, and signal level on meters is incredibly important. It definitely answers my requests, offering the best of both of worlds. You have the APx ease-of-use, but can still have all the measurements, all on one screen, when you need it.”

Regarding digital I/O, AES3 and S/PDIF are standard to the APx555, with the instrument also supporting the entire range of APx options, allowing native connectivity and analysis of audio via Bluetooth, HDMI, Digital Serial (I2S, TDM) and PDM (1-bit oversampled) formats.  The APx555 provides a full range of AES3 and S/PDIF digital output impairments, including jitter generation and analysis.

A new Advanced Master Clock handles input and output clock signals to synchronize the APx555 with external equipment. The APx series uses a modular architecture that supports a wide range of digital I/O, ensuring that as formats change APx options will be ready to support the audio industry. APx500 measurement software is under constant development, keeping pace with new standards and methods in audio test.