Chord Electronics Quartet Upscaler Officially Released

Chord Electronics officially releases the Quartet: the most radical advancement in digital tech this century

A landmark digital audio device incorporating the all-new new Blackbird WTA filter plus a built-in ADC

Kent, England, 21 May 2026: Chord Electronics, the founder-owned British hi-fi manufacturer, has officially launched the Quartet upscaler, the most radical advancement in digital audio technology this century, with full details, specifications, and pricing announced (£25,000).

The Quartet is a reference-class digital upscaler: a highly advanced device that takes digital audio data and reconstructs it with a degree of timing accuracy that conventional digital technology cannot approach. It is the most significant digital audio product in Chord Electronics' 37-year history.

Upscalers use interpolation: they mathematically reconstruct the gaps between digital samples, using advanced algorithms to restore information lost when analogue sound is captured as digital data. The quality of the reconstruction, and ultimately the sound quality, depends entirely on the sophistication of the filter used. In the Quartet, Chord Electronics’ Rob Watts has developed the most advanced filter ever incorporated into a consumer audio product: the all-new Blackbird WTA (Watts Transient Aligned), the result of 46 years of research by digital design consultant Watts.

The Quartet also incorporates a built-in ADC (analogue-to-digital converter), allowing analogue sources, including turntables, to benefit from its powerful upscaling technology for the first time in a Chord Electronics upscaler. The Quartet has been designed to partner with all Chord Electronics DACs and unlock the full potential of the flagship DAVE DAC, with its 768 kHz resolution capability. 

The digital audio problem the Quartet solves

When analogue sound is converted to digital and back again, something is lost. The leading edges of musical notes, known as transients, are subtly but consistently mistimed. Transients are central to how the brain interprets music: they convey pitch, timbre, and the placement of instruments in space. Mistimed transients mean a loss of depth, individuality, and the organic sense of a live performance. As Rob Watts explains: "Conventional digital audio is like putting a steak through a mincer and expecting to reconstruct the original from the mince." 

Core technology: the Blackbird WTA filter

Where Chord Electronics’ previous upscaler, the award-winning M Scaler, employed one million filter ‘taps’ to reconstruct audio timing (taps: the technical indicator of the complexity of the interpolation filter), the Quartet employs four million, implemented across 5x Xilinx FPGAs. The result is actually a tenfold improvement over the previous-generation WTA filter, and a tenfold improvement in transient timing accuracy, a step change rather than an incremental advance; the Quartet also boasts five times the FPGA power of the DAVE DAC.

Critically, nearly 100 per cent of the Blackbird WTA's mathematical coefficients reach the theoretical ideal (what audio engineers call the ‘sinc function’: the gold standard for a perfect reconstruction filter). In practice, this means the Quartet can rebuild the timing of a musical performance with a degree of faithfulness previously unattainable in the digital domain. 

Crucially, all filtering is implemented directly in hardware, not via FFT convolution — the software industry shortcut of converting audio into frequency data, filtering it there, and converting it back, a process that introduces the very timing errors it purports to correct.

The effect of the Blackbird WTA on music is transformational. Instruments acquire a tangible presence and a more natural sense of timbre. Bass pitch becomes cleaner and better defined. Reverberation and spatial depth, the sense of a real acoustic space, are markedly improved. 

The missing link/A Chord Electronics first: the built-in analogue-to-digital converter

The Quartet is the first Chord Electronics upscaler to incorporate an ADC, opening its upscaling technology to analogue sources for the first time. While the audio world frequently focuses on the DAC, the initial ADC can be thought of as the ‘gatekeeper’ of digital sound quality. Conventional ADCs suffer from a fundamental flaw known as ’aliasing’: a destructive form of distortion where high-frequency digital noise bleeds backward into the audible music frequencies, permanently damaging the precise timing information of the original recording. 

To bypass this, standard professional recorders use crude ‘half-band’ filters that compromise sound quality and introduce timing errors right at the source. The Quartet’s custom-designed Pulse Array ADC completely rewrites this script. By utilising proprietary, advanced decimation filters, it completely eliminates aliasing distortion from its massive 104 MHz noise-shaper output. For the music lover, this means the initial conversion from a live microphone or master tape to digital data is finally executed with absolute small-signal accuracy and zero measurable noise floor modulation. 

ADC: studio-grade transients from any analogue source

The sonic benefit of this advanced ADC architecture is a radical improvement in transparency and realism when archiving or listening to analogue sources. In listening tests comparing the Quartet ADC to industry-standard, high-end professional studio converters using pure master tapes, the sonic leap was profound. Because the Pulse Array ADC preserves the ultra-fine timing cues that the human brain relies on to map a soundstage, instruments no longer sound mechanical. The Quartet ADC ensures that the crucial starting and stopping of every single note remains perfectly intact. 

Two-box concept: Rob Watts-designed power supply incorporating sophisticated RF rejection

The Quartet is a two-box design, with a separate Rob-Watts-designed power supply incorporating sophisticated RF rejection. A proprietary pinch-off RF filter architecture prevents internal noise from propagating through the signal path, achieving the sonic purity normally associated with battery-powered devices from a mains-power-connected unit.

Further features include a 108-bit, ten-shelf lossless digital EQ, first debuted in the Mojo 2, with ±18 dB of adjustment. This enables the Quartet to accommodate a wide variation in file quality, across genre and decade, giving the user complete control over equalisation with no loss of quality.

The rear panel features isolated USB-B; dual BNC, supporting output up to 768 kHz and optical connectivity; RCA analogue inputs for the ADC; and programmable latency from 10 milliseconds to three seconds for straightforward audio-visual integration.

Features: 

·       Four million filter taps, a tenfold improvement in transient timing accuracy over the M Scaler and previous WTA filter

·       Proprietary Blackbird WTA filter architecture

·       Five Xilinx 200T FPGAs; 3,700 DSP cores; over two million lines of proprietary code

·       Built-in Pulse Array ADC so analogue sources can benefit

·       Direct-implementation filtering in hardware not FFT convolution like software

·       108-bit lossless digital EQ; programmable latency; connectivity to 768 kHz

·       Separate sophisticated RF-rejecting power supply designed by Rob Watts

·       See/hear the production version at HIGH END 2026 Vienna from 4 June

·       Compatible with all Chord Electronics DACs/Unlocks the DAVE’s full potential

Price and availability

The Quartet is available to order now priced at £25,000. It is supplied with a five-year warranty and is available in Argent Silver or Jett Black. Note: the supporting Choral Ensemble Stand System is available separately at £1,595 per tier.

Web - https://chordelectronics.co.uk/