Quartet Upscaler: A Statement Piece for Digital Audio Purists
Chord Electronics’ new Quartet upscaler is being positioned as a reference-class digital audio component and one of the most important products in the company’s 37-year history. Priced at USD 35,995 (approx. RM169,000), it clearly targets listeners assembling no-compromise, reference DAC setups where digital audio upscaling is central rather than optional. Designed to sit alongside and drive Chord’s flagship DAVE DAC, Quartet is built to unlock DAVE’s full 768 kHz capability while exerting tight control over the entire digital signal path. Instead of merely chasing higher sample rates on paper, the device focuses on filter tap technology and timing reconstruction as the primary levers for high-end audio precision. For serious systems where the DAC is already state-of-the-art, Quartet acts as a dedicated timing and interpolation brain, promising audible gains in transient clarity, space, and naturalness that standard oversampling filters cannot match.
Four Million Taps and Blackbird WTA: Inside the Timing Engine
At the heart of the Chord Quartet upscaler is the new Blackbird WTA filter, implemented with four million taps across five Xilinx FPGAs. By comparison, Chord’s earlier M Scaler employed one million taps, underscoring just how aggressively Quartet scales filter complexity. Taps represent the number of coefficients an interpolation filter can use to reconstruct missing information between digital samples; more taps allow a closer approach to the theoretical “sinc” reconstruction ideal. Chord claims a tenfold improvement over its previous WTA design and a tenfold enhancement in transient timing accuracy, backed by five times the FPGA processing power found in the DAVE DAC itself. Crucially, Quartet performs its filtering directly in hardware rather than relying on FFT convolution, which Chord argues can reintroduce timing errors. For listeners, the promise is sharper transient focus, more intelligible bass pitch, and a more coherent, lifelike spatial presentation from familiar recordings.
Timing, Transients, and the Jitter Problem Quartet Wants to Solve
Rob Watts, Chord’s longtime digital designer, frames conventional digital audio as trying to reassemble a steak from mince: something vital is lost in the process. That “something,” in his view, is timing. Transients—the leading edges of notes—carry crucial cues about pitch, timbre, and spatial placement. When they arrive even slightly late or early because of jitter, imperfect reconstruction filters, or phase inaccuracy, the soundstage can flatten, instruments blur together, and realism declines. The Quartet upscaler attacks this by using its high-tap Blackbird WTA filter to reconstruct inter-sample information with far greater temporal precision than standard DAC filters typically achieve. Rather than merely smoothing out the waveform, it attempts to rebuild the exact timing of musical events so that the brain can parse acoustic space more easily. In high-resolution digital playback chains, this positions Quartet as a tool specifically engineered to tackle jitter and phase-related artifacts at their root.
Built-In ADC: Extending Chord’s Timing Philosophy to Analog Sources
In a first for the brand’s upscalers, Quartet includes an onboard analog-to-digital converter, allowing analog sources—turntables, tape decks, and line-level components—to be digitized and passed through the same timing-focused processing as digital streams. Chord argues that conventional ADCs often suffer from aliasing, where ultrasonic noise folds back into the audible band, potentially smearing microdynamics and timing cues. To counter this, Quartet uses a custom Pulse Array ADC with proprietary decimation filters to cleanly reduce its 104 MHz noise-shaper output while minimizing noise floor modulation. The idea is to preserve transient integrity from the very first conversion step, so downstream digital audio upscaling does not try to “fix” already compromised data. For audiophiles who previously kept vinyl and other analog formats outside the digital chain, Quartet reframes the conversation: even cherished analog sources can now be integrated into a single, timing-optimized reference DAC setup.
Positioning Quartet in the Reference DAC Landscape
Quartet’s eye-watering USD 35,995 (approx. RM169,000) price and extreme engineering place it firmly in the realm of statement hardware for digital audio obsessives. Paired with a DAVE DAC, it effectively becomes a specialized digital front end dedicated to timing reconstruction, pushing an already high-end converter closer to Chord’s theoretical ideal. Its four million-tap filter, five-FPGA architecture, and integrated ADC mean it can oversee the entire signal chain—from digitizing analog sources to delivering ultra-precise digital streams to the DAC. For systems built around high-resolution streaming, disc transports, and even vinyl, Quartet offers a single hub where digital audio upscaling and filter tap technology are treated as the main determinants of perceived realism. While its cost and complexity will limit its audience, the device crystallizes an argument: resolving the fine structure of timing, not merely resolution or format, may be the next frontier in high-end audio precision.