{"product_id":"chord-electronics-quartet","title":"Chord Electronics Quartet Upscaler","description":"\u003cp\u003eThe Chord Electronics Quartet is a reference-class two-box digital upscaler that runs the new Blackbird WTA filter on five Xilinx FPGAs, processing audio with four million filter taps for a tenfold improvement in transient timing accuracy over Chord's previous WTA generation. Eight years in development by Rob Watts, it's purpose-built to unlock the full potential of Chord's flagship DAC, the DAVE.\u003c\/p\u003e\n\n\u003ch5\u003eKey Features of the Chord Electronics Quartet\u003c\/h5\u003e\n\u003cul\u003e\n  \u003cli\u003e\n\u003cstrong\u003eBlackbird WTA Filter Architecture:\u003c\/strong\u003e The new Watts Transient Aligned filter delivers at least a tenfold improvement in transient timing accuracy over Chord's previous WTA designs, with nearly 100 percent of filter coefficients reaching the theoretical ideal sinc function.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eFive Xilinx FPGAs:\u003c\/strong\u003e Five times the processing power of the reference DAVE DAC, with 3,700 DSP cores running over two million lines of bespoke code to execute the Blackbird filter without compromise.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eFour Million Filter Taps:\u003c\/strong\u003e Interpolation complexity beyond any standalone DAC, computed directly in hardware rather than via FFT convolution shortcuts that introduce additional timing errors.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eIntegrated Pulse Array ADC:\u003c\/strong\u003e A first for a Chord upscaler. Analog sources, including high-end turntables, feed RCA inputs and benefit from the same upscaling and decimation filtering that eliminates aliasing distortion.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eTwo-Box Architecture:\u003c\/strong\u003e Audio circuitry isolated from a dedicated Rob-Watts-designed power supply featuring a proprietary pinch-off RF filter architecture, achieving the sonic purity of a battery-powered device from a mains-connected unit.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003e108-bit Lossless Digital EQ:\u003c\/strong\u003e Ten-shelf equalization with plus or minus 18 dB of adjustment across the audio band, with zero degradation of signal quality.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eProgrammable Latency:\u003c\/strong\u003e Selectable delay from 10 milliseconds to three seconds for perfect lip-sync during audio-visual playback.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eComprehensive Isolated Connectivity:\u003c\/strong\u003e Galvanically isolated USB-B, dual BNC (or single BNC) and optical inputs, plus dual BNC outputs at 768 kHz optimized for pairing with the DAVE DAC.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch5\u003eEngineered for the Chord Electronics DAVE DAC\u003c\/h5\u003e\n\u003cp\u003eThe Quartet is the upscaler the \u003ca href=\"\/products\/chord-electronics-dave\"\u003eChord Electronics DAVE\u003c\/a\u003e has been waiting for. Just as the \u003ca href=\"\/products\/chord-electronics-hugo-m-scaler\"\u003eHugo M Scaler\u003c\/a\u003e was developed to extract the full potential of the \u003ca href=\"\/products\/chord-electronics-hugo-tt2\"\u003eHugo TT2\u003c\/a\u003e, the Quartet exists to do the same for the DAVE, only at a far deeper level. Five Xilinx FPGAs and four million Blackbird WTA filter taps feed the DAVE's dual BNC inputs at 768 kHz, unlocking the maximum digital resolution Chord's flagship DAC was designed to receive. If you own a DAVE, this is the front end it was built for. If you're considering one, the DAVE + Quartet pairing is the reference combination in Chord's lineup.\u003c\/p\u003e\n\n\u003ch5\u003eEight Years of Development\u003c\/h5\u003e\n\u003cp\u003eThe Quartet represents the most significant advancement in digital audio technology in Chord Electronics' history. Developed over eight years by Chord's Digital Design Consultant Rob Watts, it addresses a fundamental flaw inherent in standard digital playback: the subtle but critical mistiming of transients that obscures spatial cues, blunts attack, and flattens the realism of recorded music. Every architectural decision in the Quartet exists to correct that flaw at a level no other digital component has approached.\u003c\/p\u003e\n\n\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0555\/5073\/8528\/files\/quartet-silver-three-quarter-inline.jpg?v=1779740313\" alt=\"Chord Electronics Quartet two-box digital upscaler in Silver, three-quarter view\" style=\"width:100%;max-width:1000px;height:auto;border-radius:12px;margin:16px 0;\"\u003e\n\n\u003ch5\u003eThe Blackbird WTA Filter Architecture\u003c\/h5\u003e\n\u003cp\u003eAt the core of the Quartet's performance is the all-new Blackbird WTA (Watts Transient Aligned) filter. Representing the culmination of 46 years of specialized research, the Blackbird filter uses four million filter taps, the technical measure of interpolation complexity. That figure represents a tenfold increase over previous WTA designs and delivers a corresponding tenfold improvement in transient timing accuracy, while completely eliminating certain transient timing errors that earlier architectures could not.\u003c\/p\u003e\n\u003cp\u003eTechnically, nearly 100 percent of the filter's mathematical coefficients reach the theoretical ideal sinc function: the gold standard for perfect waveform reconstruction. All filtering is executed directly within the hardware architecture. By avoiding the software-industry shortcut of FFT convolution, which converts audio to frequency data and back, the Quartet preserves pure signal integrity and delivers unmatched transient fidelity.\u003c\/p\u003e\n\n\u003ch5\u003eFive Xilinx FPGAs and Hardware-Level Processing\u003c\/h5\u003e\n\u003cp\u003eTo process this complex interpolation algorithm without compromise, the Quartet uses five Xilinx 200T FPGAs, five times the processing power of the reference DAVE DAC. Together they provide 3,700 DSP cores running over two million lines of proprietary code. Every filter calculation is executed in hardware. Nothing is offloaded to a general-purpose processor, nothing is shortcut through frequency-domain conversion. This is what allows the Blackbird filter to operate at full tap depth in real time without introducing latency artifacts that would defeat the purpose of the filter itself.\u003c\/p\u003e\n\n\u003ch5\u003eIntegrated Pulse Array ADC for Analog Sources\u003c\/h5\u003e\n\u003cp\u003eFor the first time in a Chord Electronics upscaler, the Quartet integrates a proprietary Pulse Array ADC. Analog sources, including high-end turntables, connect via RCA inputs and benefit directly from the device's upscaling power. The ADC's advanced decimation filtering eliminates the aliasing distortion that compromises traditional analog-to-digital conversion, outperforming even dedicated studio-grade conversion hardware. For an analog source, the Quartet behaves like the front end of a reference digital chain: take the signal in, eliminate aliasing artifacts, and pass it forward at full Blackbird-grade transient resolution.\u003c\/p\u003e\n\n\u003ch5\u003eTwo-Box Architecture and the External Power Supply\u003c\/h5\u003e\n\u003cp\u003eThe Quartet's two-box configuration isolates sensitive audio circuitry from its power supply. The external PSU is itself a Rob Watts design, incorporating a proprietary pinch-off RF filter architecture, battery-level isolation characteristics, and Chord Electronics' most advanced RF filtering implementation to date. The objective: achieve the exceptional sonic purity of a battery-powered device while running from the mains. Four-stage output isolation further protects the high-rate digital outputs from any noise that could compromise the signal arriving at the DAC.\u003c\/p\u003e\n\n\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0555\/5073\/8528\/files\/quartet-silver-front-inline.jpg?v=1779740314\" alt=\"Chord Electronics Quartet upscaler and external power supply in Silver, straight-on front view\" style=\"width:100%;max-width:1000px;height:auto;border-radius:12px;margin:16px 0;\"\u003e\n\n\u003ch5\u003eLossless EQ and Programmable Latency\u003c\/h5\u003e\n\u003cp\u003eThe Quartet includes a subjectively lossless 108-bit digital EQ operating at 705.6 \/ 768 kHz, with ten-band octave control providing plus or minus 18 dB of adjustment. Because the EQ runs at the Quartet's native processing resolution, there is no degradation of signal quality regardless of how aggressively it is used. Programmable latency from 10 milliseconds to three seconds is also included, allowing perfect lip-sync alignment when the Quartet is used in an audio-visual playback chain.\u003c\/p\u003e\n\n\u003ch5\u003eComprehensive Isolated Connectivity\u003c\/h5\u003e\n\u003cp\u003eThe rear panel features comprehensive, isolated connectivity. Digital inputs include two BNC (or dual BNC), two optical, and one galvanically isolated USB-B. Digital outputs include one optical at 192 kHz, one S\/PDIF, and dual BNC at 768 kHz, capable of unlocking the maximum input resolution of the DAVE DAC. Two RCA analog inputs feed the integrated Pulse Array ADC.\u003c\/p\u003e\n\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0555\/5073\/8528\/files\/quartet-silver-rear-inline-v2.jpg?v=1779803954\" alt=\"Chord Electronics Quartet rear panel showing isolated USB-B, dual BNC outputs at 768 kHz, optical, RCA analog inputs, and external power supply\" style=\"width:100%;max-width:1000px;height:auto;border-radius:12px;margin:16px 0;\"\u003e\n\n\u003ch5\u003ePair With\u003c\/h5\u003e\n\u003cp\u003eThe Quartet is part of Chord Electronics' \u003ca href=\"\/collections\/chord-electronics-choral\"\u003eChoral product range\u003c\/a\u003e, designed to integrate visually and acoustically as a complete reference stack. Pair the Quartet and the DAVE DAC with the \u003ca href=\"\/products\/chord-electronics-ultima-pre\"\u003eChord Electronics Ultima Pre\u003c\/a\u003e for reference analog gain, then close out the chain with a \u003ca href=\"\/products\/chord-electronics-ultima-integrated\"\u003eChord Electronics Ultima Integrated\u003c\/a\u003e for single-chassis power or step up to dedicated \u003ca href=\"\/collections\/chord-electronics-power-amplifiers\"\u003eChord Ultima power amplifiers\u003c\/a\u003e for full reference separates. The \u003ca href=\"\/products\/chord-electronics-choral-ensemble-stand\"\u003eChord Electronics Choral Ensemble Stand\u003c\/a\u003e pictured with the Quartet is sold separately and provides the proper isolation and visual integration that ties the full Choral chain together.\u003c\/p\u003e\n\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0555\/5073\/8528\/files\/quartet-silver-on-choral-stand-inline.jpg?v=1779740316\" alt=\"Chord Electronics Quartet on the Chord Choral Ensemble Stand, three-quarter view\" style=\"width:100%;max-width:1000px;height:auto;border-radius:12px;margin:16px 0;\"\u003e\n\n\u003ch5\u003eThe Listening Room Difference\u003c\/h5\u003e\n\u003cp\u003eWe don't just sell high-end audio, we provide a level of service that's as refined as the products we offer. When you invest in a reference upscaler like the Quartet, you deserve more than a box on your doorstep. You deserve a partner who understands the art of sound and is committed to helping you experience it at its absolute best.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eOwner Michael Hoatson will personally deliver the Quartet to your home, anywhere in the country.\u003c\/strong\u003e Not a curbside drop-off. Painstaking setup, room placement, full system integration. Third-generation audio family with decades of experience. Bring a system to life.\u003c\/p\u003e\n\u003ch5\u003eChord Electronics Quartet Specifications\u003c\/h5\u003e\n\u003ctable style=\"width:100%;border-collapse:collapse;\"\u003e\n  \u003cthead\u003e\n    \u003ctr style=\"background-color:#f3f3f3;\"\u003e\n      \u003cth style=\"text-align:left;padding:12px;width:34%;border:1px solid #e5e5e5;\"\u003eSpecification\u003c\/th\u003e\n      \u003cth style=\"text-align:left;padding:12px;width:66%;border:1px solid #e5e5e5;\"\u003eDetail\u003c\/th\u003e\n    \u003c\/tr\u003e\n  \u003c\/thead\u003e\n  \u003ctbody\u003e\n    \u003ctr\u003e\n\u003ctd style=\"padding:12px;border:1px solid #e5e5e5;\"\u003eFilter Architecture\u003c\/td\u003e\n\u003ctd style=\"padding:12px;border:1px solid #e5e5e5;\"\u003eBlackbird WTA, 4 million taps\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd style=\"padding:12px;border:1px solid #e5e5e5;\"\u003eProcessing\u003c\/td\u003e\n\u003ctd style=\"padding:12px;border:1px solid #e5e5e5;\"\u003e5 x Xilinx 200T FPGAs, 3,700 DSP cores, 2+ million lines of code\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd style=\"padding:12px;border:1px solid #e5e5e5;\"\u003eEQ\u003c\/td\u003e\n\u003ctd style=\"padding:12px;border:1px solid #e5e5e5;\"\u003e108-bit lossless, ten-band octave, plus or minus 18 dB\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd style=\"padding:12px;border:1px solid #e5e5e5;\"\u003eADC\u003c\/td\u003e\n\u003ctd style=\"padding:12px;border:1px solid #e5e5e5;\"\u003eProprietary Pulse Array with advanced decimation filtering\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd style=\"padding:12px;border:1px solid #e5e5e5;\"\u003eDigital Inputs\u003c\/td\u003e\n\u003ctd style=\"padding:12px;border:1px solid #e5e5e5;\"\u003e2 x BNC (or dual BNC); 2 x Optical; 1 x USB-B (galvanically isolated)\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd style=\"padding:12px;border:1px solid #e5e5e5;\"\u003eDigital Outputs\u003c\/td\u003e\n\u003ctd style=\"padding:12px;border:1px solid #e5e5e5;\"\u003e1 x Optical (192 kHz); 1 x S\/PDIF; 2 x Dual BNC (768 kHz)\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd style=\"padding:12px;border:1px solid #e5e5e5;\"\u003eAnalog Inputs\u003c\/td\u003e\n\u003ctd style=\"padding:12px;border:1px solid #e5e5e5;\"\u003e2 x RCA\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd style=\"padding:12px;border:1px solid #e5e5e5;\"\u003eProgrammable Latency\u003c\/td\u003e\n\u003ctd style=\"padding:12px;border:1px solid #e5e5e5;\"\u003e10 ms to 3 seconds\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd style=\"padding:12px;border:1px solid #e5e5e5;\"\u003ePower Consumption\u003c\/td\u003e\n\u003ctd style=\"padding:12px;border:1px solid #e5e5e5;\"\u003e130 W full; 20 W standby\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd style=\"padding:12px;border:1px solid #e5e5e5;\"\u003eDimensions (each box)\u003c\/td\u003e\n\u003ctd style=\"padding:12px;border:1px solid #e5e5e5;\"\u003e7.8 cm H x 33.5 cm W x 15.2 cm D\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd style=\"padding:12px;border:1px solid #e5e5e5;\"\u003eWeight\u003c\/td\u003e\n\u003ctd style=\"padding:12px;border:1px solid #e5e5e5;\"\u003eMain unit 3 kg; PSU 3.2 kg\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd style=\"padding:12px;border:1px solid #e5e5e5;\"\u003eFinishes\u003c\/td\u003e\n\u003ctd style=\"padding:12px;border:1px solid #e5e5e5;\"\u003eBlack; Silver\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003c\/tbody\u003e\n\u003c\/table\u003e\n\n","brand":"Chord Electronics","offers":[{"title":"Silver","offer_id":42770232574048,"sku":"CHORDQUARTETSL","price":35995.0,"currency_code":"USD","in_stock":true},{"title":"Black","offer_id":42770232246368,"sku":"CHORDQUARTETBL","price":35995.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0555\/5073\/8528\/files\/chord-electronics-quartet-silver-three-quarter.jpg?v=1779736982","url":"https:\/\/listenroom.com\/products\/chord-electronics-quartet","provider":"The Listening Room","version":"1.0","type":"link"}