Chord Electronics has launched a reference-class digital upscaler designed to reconstruct audio data with timing accuracy beyond conventional digital technology.
The Quartet is the company’s first upscaler to incorporate an analogue-to-digital converter (ADC), using a proprietary filter refined over 46 years of research.
Designed by Rob Watts, the new Blackbird WTA (Watts Transient Aligned) works with the Pulse Array ADC, bringing its processing approach to analogue sources.
Upscalers mathematically reconstruct the gaps between digital samples, using advanced algorithms to restore information lost when analogue sound is converted to digital data.
But the quality of the reconstruction depends largely on the filter used.
Watts said: “Conventional digital audio is like putting a steak through a mincer and expecting to reconstruct the original from the mince."
The Quartet is designed to partner with all Chord Electronics DACs, including the flagship DAVE which supports up to 768 kHz resolution capability.
While Chord’s earlier M Scaler used one million filter ‘taps’ to reconstruct audio timing, the Quartet employs four million implemented across five Xilinx FPGAs.
The company says nearly 100 per cent of the Blackbird WTA's mathematical coefficients approach the ‘sinc function’, considered the ideal reconstruction filter.
All filtering is implemented directly in hardware rather than via FFT-based convolution.
Its custom ADC uses proprietary decimation filters to eliminate aliasing distortion from its 104 MHz noise-shaper output – resulting in what the company describes as a “sonic leap” in listening tests.
A proprietary RF ‘pinch-off’ filter architecture prevents internal noise from travelling through the signal path, achieving performance typically associated with battery-powered devices from a mains-power-connected unit.
Further features include a 108-bit, ten-shelf lossless digital EQ, first introduced in the Mojo 2, offering ±18 dB of adjustment.
Around the rear, connectivity includes an isolated USB-B input, dual BNC, supporting output up to 768 kHz, optical connections, and RCA analogue inputs for the ADC.
Programmable latency from 10 ms to three seconds aids audiovisual integration.