Quartet M Scaler: everything he said

260 posts and passages, oldest first, as one-line summaries in our words. Each link opens the original.

• 2021-08-24Watts says the item asked about is not one of his projects, and repeats that he is working on much more complex M scalers among other projects. needs context Head-Fi, Aug 2021
• 2021-08-25Watts says research is progressing and results come later next year, revealing it will be another M scaler intended to match Dave. Head-Fi, Aug 2021
• 2022-01-05Watts says benefits of longer taps diminish markedly at higher sample rates, 768 kHz seems the sweet spot, so future more costly M scalers will stay at 705/768. Head-Fi, Jan 2022
• 2022-02-11Watts says his high-end M Scaler uses a Choral (DAVE) chassis and is not 4M taps, algorithm outweighs taps, and gives SINAD of 125dB (Mojo 2) and 127dB (TT2). Head-Fi, Feb 2022
• 2022-02-15Watts attributes HF errors to ADC noise shapers and decimation, keeps HF filter off on DAVE via M Scaler, prices the Choral M Scaler at DAVE level, and rejects XMOS. Head-Fi, Feb 2022
• 2022-03-16Watts describes recording an amateur orchestra with a Blumlein ribbon mic into a Focusrite ADC, compares playback with live, and blames lost depth, transients and timbre on the ADC. Head-Fi, Mar 2022
• 2022-04-10Watts describes twisting eight PTFE solid cores per conductor, hopes to finish the xM scaler and ADC later this year, and says the next ADC prototype will take ribbon mics. Head-Fi, Apr 2022
• 2022-07-11Watts says Chord units need stereo PCM downmixes, surround is not on his radar, the Shield's 0.63 sec delay allows full 1M taps, and a Choral prototype supports 1 sec. Head-Fi, Jul 2022
• 2022-08-19Watts says a disclosed scaler to match DAVE, three or four years in work and priced like DAVE, won't replace the Hugo M Scaler; more taps help, but algorithm matters. AVstore 7:51
• 2022-08-19Watts says DAVE with his prototype scaler and Dan Clark Audio Stealth headphones came close to his live recordings, but depth was one-third or 50 percent less. AVstore 46:35
• 2022-09-16Watts says vinyl's clicks and lack of transparency rule it out, his M scaled Hugo 2 and DAVE are far more involving, and his recording played back warmer than live. Head-Fi, Sep 2022
• 2022-09-18Watts says an NVIDIA device's negative video delay lets him run the M Scaler at 1 million taps, a bigger M Scaler has one-second delay working, and he dislikes surround. The Source AV 4:38
• 2022-09-18Watts says companies update products after 3 years; he needed mature technology, and work over COVID on a bigger M Scaler has bottomed out interpolation, after 40 years. The Source AV 15:25
• 2022-09-18Watts says with DAVE and a prototype of the new scaler, left-right accuracy of his recordings is identical to perfect, but depth is not. The Source AV 18:19
• 2022-10-18Watts says Krisdonia noise is the likely problem, power-bank tests wait until after his Asia trip, and a 100 Wh Bixpower would run an M Scaler 8 hours. Head-Fi, Oct 2022
• 2022-10-25Watts says the Ultima DAC and Choral scaler take much of his time, notes he hears to 15kHz at 62, and says HF hearing loss does not affect transient-timing perception. Head-Fi, Oct 2022
• 2022-10-25Watts says a video mode supporting the Nvidia Shield's 1 s delay will be available on the Choral M Scaler, and it makes a tremendous difference. Head-Fi, Oct 2022
• 2023-01-02Watts says he is not working on it now, as he must finish the Choral M scaler and the Ultima DAC first. needs context Head-Fi, Jan 2023
• 2023-01-08Watts says only an optical source plus battery on the M Scaler guarantees noise-free operation, as mains units leak noise even via optical; the Choral M Scaler addresses this. Head-Fi, Jan 2023
• 2023-03-26Watts says the limit is reached when doubling taps is inaudible; during Covid he investigated it while working on a scaler to match DAVE, stressing reconstruction accuracy over taps. Eric's Hi-Fi 3:09
• 2023-03-26Watts says that tap count means a WTA function spanning two billion years past and future, which is impossible; he found an improvement to reveal with the new scaler. Eric's Hi-Fi 5:21
• 2023-03-26Watts says the coming product costs about as much as DAVE; he designs to performance, Chord prices from materials cost, and it has many FPGAs and a new technique. needs context Eric's Hi-Fi 7:47
• 2023-03-26Watts says his focus is the new scaler and the Ultima DAC; other projects wait until the Ultima DAC is finished, and DAVE replacement work has not started. Eric's Hi-Fi 8:40
• 2023-04-03Watts says what is coming up is a new scaler to match DAVE. Amplify Audio 41
• 2023-07-13Watts says he is busy on the Ultima DAC and a Choral-range M scaler for Dave, expects a pre-production unit soon, and has agreed a new name. Head-Fi, Jul 2023
• 2023-07-15Watts says all M scalers will work with all current DACs, including Mojo 2 and Hugo 2 via dual data, that scaler benefits need long-term listening, and urges forum civility. Head-Fi, Jul 2023
• 2023-07-23Watts says a more complex EQ is technically possible for the new M scaler given its FPGA capacity. Head-Fi, Jul 2023
• 2023-07-24Watts says the Choral range M scaler uses multiple Xilinx 200T FPGAs, since bigger FPGAs cost four times as much for a given performance. Head-Fi, Jul 2023
• 2023-09-23Watts describes his cycle of FPGA design, simulation, digital measurement and AB listening tests, and says he has more things to try on the new scaler. Head-Fi, Sep 2023
• 2023-10-01Watts says a surface bright at infrared dissipates more, and that the new scaler he is working on had heat sinking and power dissipation problems from his own mistakes. The Source AV 46:59
• 2023-10-05Watts says unanodized Hugo M Scaler prototypes showed anodizing doubles heat-sink performance, and Choral scaler heat issues led to a redesign of metalwork, PCB and FPGA code. Head-Fi, Oct 2023
• 2023-11-08Watts says Ultima DAC PCBs test well, but he is finishing the Choral range M Scaler first and expects to be full time on the Ultima DAC by January 2024. Head-Fi, Nov 2023
• 2023-12-24Watts names his upcoming projects as the M scaler to match DAVE and the Ultima DAC, and says certainly not TT3. Head-Fi, Dec 2023
• 2023-12-25Watts says he has been working with pre-production units of the Choral M scaler this month, everything works, and it exceeds his sound-quality expectations from earlier prototypes. needs context Head-Fi, Dec 2023
• 2024-03-17Watts says Quartet will have 176.4/192 kHz toslink and coax outputs plus dual BNC at 705.6/768 kHz. Head-Fi, Mar 2024
• 2024-03-18Watts says Quartet's single BNC and optical outputs are fixed at 176.4/192k, decimated from 705.6/768 kHz with new filters and separately noise shaped for 4FS. Head-Fi, Mar 2024
• 2024-03-28Watts says Quartet will have more complex lossless EQ built in, which he is finishing now. Head-Fi, Mar 2024
• 2024-04-05Watts says well over 90% of DAC sound quality depends on interpolation filter and DAC implementation, criticizes listeners and reviewers, and says Quartet holds five 200T FPGAs. Head-Fi, Apr 2024
• 2024-04-08Watts rebuts a claim that more taps make transients collide, saying longer sinc filters make transients independent, and each tap doubling improved sound. Head-Fi, Apr 2024
• 2024-04-17Watts says pre-production Quartet into Dave beat an M scaled Dave, it works with all current DACs, and a dedicated bit clock would only add RF. Head-Fi, Apr 2024
• 2024-05-04Watts says Quartet replacing a Hugo M Scaler on another listener's Dave made instruments sound real, and describes ADC decimation filter work and the 104MHz pulse array ADC. Head-Fi, May 2024
• 2024-05-04Watts says the Quartet M Scaler will not launch at Munich, but a prototype can be heard on trade days, and the production version will differ slightly. Head-Fi, May 2024
• 2024-05-10Watts says a power supply feeds Quartet and has a very sophisticated RF filter built into it. Reactcore 0
• 2024-05-10Watts says dual BNC outputs are happening as well. Reactcore 0
• 2024-05-10Watts says the changes in this unit are quite a lot compared to the M Scaler. Reactcore 9
• 2024-05-10Watts says this is 4 million taps, followed by an unclear phrase transcribed as 'there's like two million big'. Reactcore 18
• 2024-05-10Watts poses the question of why they run at 768 kHz. Reactcore 9
• 2024-05-10Watts names 16FS at 1.6 MHz as an alternative rate and says there is a sweet spot. needs context Reactcore 14
• 2024-05-10Watts says the amount of data the upsampler is looking at is also critically important for sound quality, and begins to describe a trade-off. needs context Reactcore 47
• 2024-05-10Watts says the sweet point is 16FS and that DAVE takes up 16FS. Reactcore 1:00
• 2024-05-16Watts says Quartet M Scaler took 6 years, his most complex project, with five FPGAs (the same as Hugo M Scaler), two million lines of code and 2,500 discrete components. ConvinceMeAudio 42
• 2024-05-16Watts says Quartet has a power supply delivering 75 amps to the FPGAs, plus a separate power supply of his own design whose key element is an RF filter covering DC to 10 gigahertz. ConvinceMeAudio 1:31
• 2024-05-16Watts says 200-plus-component RF filters at Quartet's input and supply output keep RF out of Quartet and DAVE; stopping circulating currents makes BNC cable quality irrelevant. ConvinceMeAudio 2:12
• 2024-05-16Watts says this isolation gives much better sound quality, and that isolation through the RF filters is fundamentally crucial. ConvinceMeAudio 2:55
• 2024-05-16Watts says 16-bit is an arbitrary target; his research found even infinitely small timing errors are perceptible, which led him to improve the interpolation filter in Quartet. ConvinceMeAudio 8:31
• 2024-05-16Watts calls it a good question but says he will answer it at launch, since technical details are not being discussed today. needs context ConvinceMeAudio 9:35
• 2024-05-16Watts confirms it still uses dual BNC, saying he had to decide between an optical connection and keeping dual BNC. ConvinceMeAudio 10:10
• 2024-05-16Watts says optical would require changing the DAC and fails anyway with DAVE and scaler both on mains, so he kept dual BNC and contained the noise inside the product. ConvinceMeAudio 10:19
• 2024-05-16Watts says the noise does not leak into the mains, so it sounds like battery power and BNC cables matter less than with the Hugo M Scaler. ConvinceMeAudio 10:47
• 2024-05-16Watts says the BNC drivers are improved: the Hugo M Scaler had one stage of galvanic isolation, while this has three, each with built-in RF filters. ConvinceMeAudio 11:00
• 2024-05-16Watts answers that the scaler's source inputs are USB, optical and BNC. needs context ConvinceMeAudio 11:31
• 2024-05-16Watts says it can be used with Mojo 2 or any Chord DAC, because they all accept dual BNC. ConvinceMeAudio 11:42
• 2024-05-16Watts agrees; the price is not set because the design is not quite finished, but it will cost more than DAVE. ConvinceMeAudio 12:03
• 2024-05-16Watts says Quartet has two sets of BNC outputs, so it can feed two different products anyway. ConvinceMeAudio 14:16
• 2024-05-16Watts says Quartet has that built in, with separate drivers and separate outputs for each. ConvinceMeAudio 14:33
• 2024-05-16Watts says the two outputs are not isolated from each other, sharing a supply and ground, but both are isolated so each DAC is isolated from the scaler. ConvinceMeAudio 14:42
• 2024-05-16Watts corrects the interviewer: the product is called the Quartet M Scaler. The Speaker Shack 16
• 2024-05-16Watts says the product is named Quartet because it has 4 million taps. The Speaker Shack 18
• 2024-05-16Watts calls it a big project, says he started work when the Hugo M Scaler was finished, and says it has taken 6 years (opening words unclear in transcript). needs context The Speaker Shack 29
• 2024-05-16Watts says development took long because of engineering complexity and because it was a research exercise into interpolation filters: how many taps are needed to perfectly reconstruct. needs context The Speaker Shack 45
• 2024-05-16Watts says it is going to be priced but the price is not yet known. needs context The Speaker Shack 3:51
• 2024-05-16Watts lists five FPGAs, two million lines of code, 2,500 discrete components and a 75 amp supply of his own design, with RF filters from DC to 10 GHz. The Speaker Shack 4:00
• 2024-05-16Watts says the RF filter has over 200 components and the same filter sits at Quartet's input and at the power supply output, controlling noise in and out. The Speaker Shack 4:43
• 2024-05-16Watts says this isolates Quartet (phrase partly garbled), giving much better sound quality and less need to worry about BNC connections. The Speaker Shack 5:00
• 2024-05-16Watts says a few recording engineers have listened to it and were blown away. needs context The Speaker Shack 5:50
• 2024-05-16Watts says one recording engineer, hearing a track he mixed some time ago, heard faulty edits he had never heard before. needs context The Speaker Shack 6:00
• 2024-05-16Watts defines focus: keeping track of a quiet instrument as a crescendo builds; normal digital loses it, while with Quartet quiet instruments stay clearer under loud ones. The Speaker Shack 6:27
• 2024-05-16Watts says reproduced audio is poor at instrument power and tracking quiet background players, and Quartet taught him how important timing information is for both. The Speaker Shack 7:31
• 2024-05-17Watts says he has been very busy with the Quartet M Scaler. AVstore 16
• 2024-05-17Watts says he spent six years on Quartet, his most complex project, which uses five FPGAs of the M Scaler's type instead of one and two million lines of code. AVstore 21
• 2024-05-17Watts says the work involved much experimentation fine-tuning the algorithm, and that the device contains two and a half thousand discrete components. needs context AVstore 1:00
• 2024-05-17Watts says Quartet is as complex as a PC in a small box and has a separate 75 amp power supply to feed its FPGAs' power requirements. AVstore 1:13
• 2024-05-17Watts says separating it reduces processing noise and isolates Quartet from the DAC: RF filters in the supply and Quartet's input stage make it behave like a battery. AVstore 1:38
• 2024-05-17Watts answers 4 million taps. needs context AVstore 4:31
• 2024-05-17Watts says the four million taps are why it is being called Quartet. needs context AVstore 4:34
• 2024-05-17Watts says the algorithm matters much more than the number of taps, and it has been optimized to reconstruct timing much more accurately than before. AVstore 4:40
• 2024-05-17Watts says it already has this: the DSP EQ has 5 settings, off plus 4 settings the user can set. Head-Fi, May 2024
• 2024-05-28Watts reports strong press and user reactions to Quartet with DAVE in Munich, says rivals have not closed DAVE's technical lead, and that Quartet lifts DAVE further. Head-Fi, May 2024
• 2024-05-29Watts shows a pre-production Quartet M Scaler prototype designed to match DAVE: 6 years of development, two million lines of code, 75 amp supply, five 200T FPGAs. HIFICLUBE.NET JVH 8
• 2024-05-29Watts states the tap count: 4 million taps. needs context HIFICLUBE.NET JVH 1:09
• 2024-05-29Asks (attribution uncertain) whether the product is called Quartet because it has 4 million taps. HIFICLUBE.NET JVH 1:22
• 2024-05-31Watts says he is not under contract with Chord, a scaler needs physical separation from the DAC, DSD sounds unreal, and subjective impressions can be characterized objectively. Head-Fi, May 2024
• 2024-06-18Watts says most of six years went into developing the Quartet M Scaler, partly a research study of interpolation filters and transients, through five board versions and many FPGA program changes. article, Jun 2024
• 2024-06-18Watts answers that it is named Quartet because it has four million taps. needs context article, Jun 2024
• 2024-06-18Watts says the M Scaler is guaranteed better than a 16-bit reconstruction and Quartet better still, and explains how the brain uses transient timing for separation, location, timbre, note edges and bass pitch. article, Jun 2024
• 2024-06-18Watts explains how interpolation modulates transient timing, harming separation, timbre, bass and fatigue, says any timing error is perceptible, and lists Quartet's five FPGAs, 2,500 components, 75-ampere supply and two million code lines. article, Jun 2024
• 2024-06-18Watts says the first Quartet installation outside the family, in Singapore, gave a night and day difference on a 1957 Coltrane track, with instruments instantly placed in space. article, Jun 2024
• 2024-06-18Watts says Quartet will cost more than DAVE, and describes Spice-modeled 'pinch-off' RF filters in its separate supply and input, isolating DAVE from its noise and making the sound warmer and smoother. article, Jun 2024
• 2024-06-18Watts says Quartet links over BNC like the M Scaler but has three FPGA isolation stages to its one, making it less sensitive to BNC cables. article, Jun 2024
• 2024-06-24Watts says he does not recall calling the Hugo M Scaler a mess, says it remains essential on his flights, and calls Quartet a major advance on it. Head-Fi, Jun 2024
• 2024-06-24Watts defers Quartet's 4M-tap details to launch, says 5.2 uS at 192kHz is still too big, calls DSD a mess for timing, and describes his reference tracks. Head-Fi, Jun 2024
• 2024-06-28Watts says Quartet supports the dual AES format like the Hugo M Scaler, so a third party could build a dual BNC to USB converter, though not trivially. Head-Fi, Jun 2024
• 2024-07-12Watts gives the product's full name: the Quartet M Scaler. HIFICLUB 55
• 2024-07-12Watts calls Quartet a bigger, more exotic, more expensive Hugo M Scaler, six years in the making with three to four man-years of work, his most complex project. HIFICLUB 57
• 2024-07-12Watts says the M Scaler's 1 million taps improved pitch, timbre and staging; Quartet uses more FPGA power for 4 million taps and an improved filter. HIFICLUB 14:45
• 2024-07-12Watts says Quartet taught him that the Hugo M Scaler's better-than-16-bit reconstruction is not enough; much better is needed, with effects too small for measurement equipment. HIFICLUB 20:23
• 2024-07-12Watts says he developed a supply with special RF filters giving battery-like isolation, reducing sensitivity to BNC cables and sources, and raises why he does not build a network player. HIFICLUB 46:35
• 2024-07-12Watts rejects criticism that audible source differences mean the M Scaler is badly designed: it passes EMC and has galvanic isolation; Quartet is isolated further. HIFICLUB 48:49
• 2024-07-12Watts says he has not started a DAVE replacement; a DAVE owner who sold his unit heard Quartet with DAVE at Munich and decided to buy DAVE again. HIFICLUB 50:50
• 2024-07-12Watts says he began demoing to audiophiles, first a friend in Singapore, and was anxious because a system in someone else's room always sounds wrong to you. HIFICLUB 51:39
• 2024-07-12Watts says years of small improvements made progress hard to judge; plugging Quartet into his friend's system with M Scaler and DAVE made a huge difference, like forgetting the hi-fi. HIFICLUB 52:22
• 2024-07-12Watts says it was one of five such experiences in his life; the friend, who owns DAVE, TT2 and two M Scalers, expected better but not this much better. HIFICLUB 53:11
• 2024-07-12Watts says Quartet elevates DAVE to a new level, citing an ex-DAVE owner who now has to buy DAVE again. HIFICLUB 53:56
• 2024-07-12Watts greets Korean fans and invites them to listen to Quartet when it arrives in Korea, saying it is all about enjoying music. HIFICLUB 54:34
• 2024-07-18Watts says 1M taps gave 16-bit accuracy but any timing error is perceptible, describes the isolated 75 ohm coax output, and says flight-ready Quartet needs better FPGAs. Head-Fi, Jul 2024
• 2024-07-24Watts says to wait for launch; he has only stacked the units, expects no difference given his screening and filtering design, but must prove it with PSU listening tests. needs context Head-Fi, Jul 2024
• 2024-07-25Watts says he has worked on Quartet at least 6 years, since the Hugo M Scaler was finished, made discoveries over COVID; it matches DAVE, price undecided. Hifi Pig TV 34
• 2024-07-25Watts says it is two boxes, with a separate supply, because its five large FPGAs need 75 amps; it has 4 million taps, 4 times the Hugo M Scaler. Hifi Pig TV 1:28
• 2024-07-25Watts says he has never had security issues carrying an 'MSC' (probably M Scaler) or DAVE, or the Quartet to Munich as carry-on; Mojo 2 once caused an issue. Hifi Pig TV 3:43
• 2024-07-25Watts says he travels with the prototype Quartet because he still has coding to do at shows, and because he loves its sound, which makes good recordings sound more real. Hifi Pig TV 4:39
• 2024-07-25Watts says the goal is the illusion of real musicians in a real space, calls Quartet a big step toward it and the hardest product he has worked on. Hifi Pig TV 5:13
• 2024-09-29Watts says it is called the Quartet M Scaler, was shown possibly too early at Munich, and has taken more of his time since 2018 than anything in his life. The Source AV 3:16
• 2024-09-29Watts says he funds the project himself and is paid a royalty once Chord produces something; he did it for musical sound quality first and for intellectual reasons second. The Source AV 3:43
• 2024-09-29Watts says the M Scaler made a huge difference, so he wanted to know how much further the envelope could be pushed, and the project led him to unexpected findings. The Source AV 4:09
• 2024-09-29Watts says this is 4 million taps. needs context The Source AV 4:56
• 2024-09-29Watts says it has five 200T FPGAs. needs context The Source AV 4:59
• 2024-09-29Watts says it works to a different level of precision than the existing M Scaler, will not replace the Hugo M Scaler, and is a lot more expensive. needs context The Source AV 5:05
• 2024-09-29Watts says the design is unfinished; he hopes to sign it off in a couple of months, then production takes about six months, so next year. needs context The Source AV 5:24
• 2024-09-29Watts says some design work remains, but most of his work now is testing and evaluation, and that testing turned up interesting findings that delayed going into production. The Source AV 5:51
• 2024-09-29Watts says listening tests showed he needed far greater filter coefficient accuracy, so he computed at 40 decimal places with aggressive noise shaping but could not verify performance. The Source AV 6:30
• 2024-09-29Watts says his son wrote an FFT algorithm from first principles; at a thousand-digit resolution distortion and noise were at 3,500 dB, proving the tool and computation correct. The Source AV 7:12
• 2024-09-29Watts says his son, a Tonmeister student at Surrey on a recording-studio placement in Belgium, built the tool in weeks, removing the 300 dB limit of Windows 64-bit floating point. The Source AV 8:10
• 2024-09-29Watts says running the coefficients through the new tool showed results nothing like expected because his coefficient tools were flawed, so he changed the tool set for much better precision. The Source AV 8:53
• 2024-09-29Watts says all the listening tests he had done on Quartet had to be rerun. The Source AV 9:43
• 2024-09-29Watts says that with new coefficients and a different calculation routine, the subjectively optimized numbers came out the same, a relief confirming his listening was correct. The Source AV 9:50
• 2024-09-29Watts says the result is better sound, not a huge difference; he works until fully happy, then presses the button, Chord goes into production, and he leaves. The Source AV 10:30
• 2024-09-29Watts says that with hardware and metalwork done, he has taken Quartet to a few select audiophiles, including a Singapore friend who owns many Chord products. The Source AV 13:01
• 2024-09-29Watts says the friend keeps a separate apartment for hi-fi, with a main system and a mini system, and that he plugged Quartet into the friend's DAVE. The Source AV 13:49
• 2024-09-29Watts says six years of hundreds of small improvements cost him a sense of scale, so trying a new product in someone else's system shows the real improvement. The Source AV 14:19
• 2024-09-29Watts says that on the friend's system the instruments suddenly sounded like reality, a night-and-day change rather than a small one. The Source AV 15:09
• 2024-09-29Watts says that with another audiophile, not using DAVE, the difference was hardly audible, and the problem turned out to be his power amp. The Source AV 15:29
• 2024-09-29Watts says Quartet reconstructs transient timing more accurately, aiding timbre and instrument separation; digital mis-times transients, only the M Scaler approach recovers them, and it put DAVE in a new game. The Source AV 15:46
• 2024-09-29Watts says Quartet works well with DAVE, but warns about using DAVE with a Class D power amplifier. The Source AV 16:28
• 2024-09-29Watts says pre-production metalwork exists with a few tweaks left, and that it has a separate power supply. needs context The Source AV 16:54
• 2024-09-29Watts says photographs of it have been published so people can see it. needs context The Source AV 17:08
• 2024-09-29Watts says it is a Choral range product with a separate power supply. needs context The Source AV 17:15
• 2024-09-29Watts says it will be more expensive than DAVE, hopefully not by too much, which he knows from his rough idea of the bill of materials cost. needs context The Source AV 18:58
• 2024-09-29Watts says Chord will not disclose the bill of materials cost to him because he is separate, but prices fairly as a standard multiple of it. The Source AV 19:11
• 2024-09-29Watts says he would be severely upset if they are not showing it at this show next year. needs context The Source AV 19:40
• 2024-09-29Watts says Chord has asked why he is late; new maths and measurement tools revealed something new and gave better sound, probably an incremental rather than night-and-day change. The Source AV 20:03
• 2024-09-29Watts says that with Quartet he has definitely broken through the ceiling. The Source AV 21:04
• 2024-09-29Watts says reaction was very positive; one unnamed reviewer went completely silent for half a minute to a minute after listening. needs context The Source AV 21:25
• 2024-09-29Watts says Quartet is about making the design work for him; if only one person, like his Singapore friend, loves Quartet, that is fine. The Source AV 30:18
• 2024-09-29Watts says that when they launch Quartet there will be lots of trips. The Source AV 31:32
• 2024-10-02Watts says a new unlimited-precision FFT showed his old coefficients were wrong; corrected ones kept the same preferred settings, improved sound, and delayed everything 3 months. Head-Fi, Oct 2024
• 2024-10-02Watts says he uses a scaler with TT2 on his main loudspeaker system and travels with Quartet paired with Hugo 2 in hotels, and that all are elevated in performance. Head-Fi, Oct 2024
• 2024-10-03Watts says PCB ground layers screen EMC, the new coefficient work needs a whole 200T FPGA and won't reach the Hugo M Scaler, and single-ended has the transparency edge. Head-Fi, Oct 2024
• 2024-11-04Watts says his in-DAC switching regulators run at 500kHz to 1MHz, while Quartet's mains supply runs at 70k followed by a regulator above 500k and a passive RF filter. Head-Fi, Nov 2024
• 2024-12-15Watts says Chord occupies Maidstone's original water pump-house, criticizes reviewers praising recycled old DAC tech as innovation, and says he has been busy finishing Quartet. Head-Fi, Dec 2024
• 2025-01-13Watts says Quartet's price is unknown but it will ship with its own PSU, the only one meeting its demands after extreme RF filtering work. Head-Fi, Jan 2025
• 2025-02-17Watts says the Quartet M Scaler shown at the show was started six years ago, combining research into interpolation filters with multi-FPGA development; the problem is transient timing. audio-2G 4:00
• 2025-02-17Watts says modern DSPs miss that accuracy but his Mojo 2 cores and a similar Quartet core do, so EQ keeps depth intact; he tests with alternating half-dB bands. audio-2G 18:39
• 2025-03-27Watts says Mojo 3 is news to him and a mobile M scaler awaits FPGAs: no low-cost successor to the 28nm 200T exists, and 16nm parts would dissipate about 8W. Head-Fi, Mar 2025
• 2025-05-12Watts says his Xilinx 200T FPGA has 720 DSP cores; the Quartet M Scaler he is developing to match DAVE has five 200T, two and a half thousand DSP cores. Audiophile Junkie 16:33
• 2025-05-12Watts says there is still a delay: 0.7 of a second with the M Scaler and three seconds with the Quartet M Scaler. Audiophile Junkie 17:12
• 2025-09-14Watts says the big project he has been working on since 2018 is the Quartet M Scaler. The Source AV 7:30
• 2025-09-14Watts says it is not a replacement for DAVE but an advanced version of the Hugo M Scaler, packed with new technology from six or 7 years of work. The Source AV 8:42
• 2025-09-14Watts says since having Quartet it has been disappointing to fly with just an M Scaler, because you get used to Quartet's sound quality. The Source AV 15:46
• 2025-09-14Watts says he has demoed Quartet and the M Scaler where you could barely hear a difference because the system was not transparent. The Source AV 17:36
• 2025-09-14Watts says he will show Quartet to a group of audiophiles in Asia following its progress, and will attend Singapore Formula One, where Elton John is playing. The Source AV 19:08
• 2025-09-14Watts says they are showing Quartet at the Tokyo show. The Source AV 21:54
• 2026-03-17Watts says the biggest DAC problem is reconstructing transient timing, which the brain uses for separation, timbre, bass pitch and depth; Quartet, six or seven years' work, launches next year. ecoustics 21:04
• 2026-03-17Watts says it is an M Scaler for DAVE: the upsampler feeds DAVE. needs context ecoustics 22:11
• 2026-03-17Watts says a cello recorded four meters away sounds two meters on DAVE and 2.5 to 3 with Quartet; commercial ADCs noise-shape to 140 dB, his ADC about 301 dB. ecoustics 45:04
• 2026-03-17Watts says the expensive scaler for DAVE has 'five two hundred T' FPGAs and a 75 amp supply that can create a lot of noise, which he had to keep from corrupting the DAC. ecoustics 1:10:13
• 2026-03-17Watts says many DAVE sales, and Quartet sales once people have heard it, came from people who started with a $650 Mojo and heard something new. ecoustics 1:18:21
• 2026-03-17Watts says Quartet is passing to production with a couple of months of code and testing left; its boards have 2,500 components needing two cascaded pick-and-place machines. ecoustics 1:24:36
• 2026-03-17Watts says he listened to a Mojo through Quartet last week and it transforms a Mojo as much as it does DAVE. ecoustics 1:25:47
• 2026-03-17Watts says he is not recommending buying a Quartet and a Mojo 2. ecoustics 1:26:03
• 2026-03-24Watts says DAC64 was revolutionary, he has worked with Chord since, also designed audio chips as a semiconductor designer, now works full time on Chord development, and Quartet took 8 years. Audio Force 4:07
• 2026-03-24Watts says Quartet took 8 years of constant development, changed his understanding of interpolation filters, and brings listeners closer to the sound of live music. Audio Force 4:40
• 2026-03-24Watts says DAVE is currently the best DAC in the world for transparency, but Quartet puts DAVE in a completely new category, improving everything about the sound. Audio Force 5:09
• 2026-03-24Watts agrees absolutely, saying it rests on solid technical reasons and very advanced technology built into Quartet. needs context Audio Force 5:38
• 2026-03-24Watts says Quartet as a project started in 2018 and has taken 8 years. Audio Force 9:36
• 2026-03-24Watts says Quartet began as a better Hugo M Scaler but became a study of interpolation filters; his unique WTA algorithm was tuned through thousands of listening tests. Audio Force 9:47
• 2026-03-24Watts says the ideal is impossible with a standard filter, so he developed a completely new type of interpolation filter called Blackbird WTA. Audio Force 13:51
• 2026-03-24Watts says Blackbird WTA optimizes both factors independently, giving a 10 times improvement in sound quality, the primary difference between Quartet and his earlier work. Audio Force 14:13
• 2026-03-24Watts says it is only for Quartet. needs context Audio Force 14:59
• 2026-03-24Watts says Blackbird WTA massively improves pitch, timbre, separation and location, especially depth, and a quiet background instrument is no longer swamped when a loud one enters. Audio Force 15:32
• 2026-03-24Watts says digital music can sound mechanical and jerky with rhythm that does not flow, and with Blackbird WTA things flow much more naturally. Audio Force 16:29
• 2026-03-24Watts says DAVE's transparency needs no Quartet to appreciate, and Chord has had no need to change it while competitors replace products every two or 3 years. Audio Force 18:55
• 2026-03-24Watts says DAVE is used in famous recording studios for its transparency, so there was no pressure to improve it, but Quartet takes DAVE to a profoundly new level. Audio Force 19:17
• 2026-03-24Watts says yes, Quartet just changes everything. needs context Audio Force 20:28
• 2026-03-24Watts says he wants people convinced by their own listening, and that every DAVE owner who has heard Quartet has been very excited, commenting they knew it would sound a lot better. Audio Force 20:38
• 2026-03-24Watts says Quartet has five 200T FPGAs, five times the Hugo M Scaler's chip count, with 75 amp peak currents, so the supply must block noise both in and out. Audio Force 24:08
• 2026-03-24Watts says he developed a complex new 'pinch-off RF filter' to keep RF in and out of Quartet, aiming at battery sound, since lithium-ion or car batteries are the ultimate source. Audio Force 25:45
• 2026-03-24Watts says Quartet's supply makes it sound the same as running on batteries, so owners cannot upgrade it: it already has the best possible power supply. Audio Force 26:36
• 2026-03-24Watts says the most important thing is understanding, and Quartet radically improved his understanding of how interpolation filters work. Audio Force 27:43
• 2026-03-24Watts says he used Quartet in listening tests for the various changes and was amazed. needs context Audio Force 28:45
• 2026-03-24Watts says Mojo 2 sounded remarkably good with Quartet as its source, showing the correct source fundamentally improves even something as humble as Mojo 2. Audio Force 28:54
• 2026-03-24Watts says Mojo 2 is inexpensive and limited by its source, then introduces Quartet's analog input, a pulse array A-to-D converter, prompted by recording engineers praising DAVE. Audio Force 29:11
• 2026-03-24Watts says engineers wanted the best A-to-D using DAVE's technology, which now works in Quartet, and he has been making test recordings of its performance. Audio Force 29:58
• 2026-03-24Watts says his mother immediately heard the difference between a high-performance ADC and Quartet's ADC on a phone speaker, so recording quality will improve for everyone. Audio Force 30:22
• 2026-05-03Watts says he is showing the Quartet M Scaler, developed over the last 8 years, with new interpolation filter technology that he says raises digital reproduction to a new level. Audio Force 1:05
• 2026-05-03Watts says Quartet has a fundamentally better interpolation filter, the Blackbird WTA filter, the new development shown at the show. Audio Force 7:39
• 2026-05-03Watts says Quartet (transcribed 'Cortax') has no measurable noise floor modulation while all other DACs, at any price, do, so separation and timbre suffer less with Chord DACs. Audio Force 14:34
• 2026-05-03Watts says the pulse array's small-signal accuracy and lack of noise floor modulation matter for ADCs too; Quartet is the first product using his pulse array ADC, and a Pro Audio ADC is in development. Audio Force 16:00
• 2026-05-03Watts urges listeners to hear Quartet M Scaler at a dealer, to ignore the nonsense and enjoy music, and says 1930s recordings sound really good as his system improves. Audio Force 20:02
• 2026-08-30Watts says the biggest project is a pro audio interface using Quartet's pulse array ADC; Quartet took him 8 years and is his most complicated product. The Source AV 2:17
• 2026-08-30Watts says they spent a studio day recording piano and a singer at 768 kHz with Quartet, and he has never heard piano sound as good. The Source AV 3:00
• 2026-08-30Watts says Quartet is an expensive scaler that adds sound quality at the next level; once used to it you cannot listen without it. The Source AV 4:30
• 2026-08-30Watts says the first batch is nearly sold out before units reach dealers, and he is humbled that people have paid for Quartet, often without hearing it. The Source AV 4:57
• 2026-08-30Watts says a single-stage filter trades off two problems like a seesaw; his Blackbird WTA solves each in turn, a new structure cutting the delay to tens of seconds. The Source AV 8:23
• 2026-08-30Watts says the approach is radically different and he is super excited by the sound quality they are getting from Quartet. needs context The Source AV 9:14
• 2026-08-30Watts says yesterday's talk covered Quartet, interpolation and the Blackbird WTA; this afternoon's is on the A to D converter, and he asks Daniel about the recording. The Source AV 17:49
• 2026-10-02Watts says his informal relationship with Chord dates from 1997, Chord pays only once products are in production, and he spent 8 years developing Quartet with his own finance. HiFi Buys 2:01
• 2026-10-02Watts says they have not yet talked about the ADC, which is in Quartet. HiFi Buys 1:40:55
• 2026-10-02Watts says Quartet has a one-second delay mode because the NVIDIA Shield can set a one-second video delay. HiFi Buys 2:14:45
• 2026-10-02Watts says he never de-engineers a product to sell a pricier one, calling it ethically wrong, and Quartet was a research exercise into interpolation accuracy and its limits. HiFi Buys 2:33:16
• 2026-10-11Watts says Quartet took longer because his son Daniel built unlimited-precision coefficient tools; a test sine computed to 3,000 decimal places showed distortion and noise about 3 thousand dB down. Distorsiuni Interioare 8:25
• 2026-10-11Watts says newly identified issues added 2 years; Quartet was finished when every possibility was explored, with no deadline from Chord, as research plus product development. Distorsiuni Interioare 9:38
• 2026-10-11Watts says the digital recording lost soundstage depth and was warmer than the original, partly from the ribbon mic, with much of the difference being speed, impact and power that Quartet brings out. Distorsiuni Interioare 11:17
• 2026-10-11Watts says Quartet contains a pulse array ADC; two test recordings at 768 kHz were made with it, and he expected better separation, depth and power. Distorsiuni Interioare 11:57
• 2026-10-11Watts says an ADC has a DAC in its feedback loop; the surprise was far more accurate pitch of female vocalists than pro ADCs give, which he attributes to aliasing. Distorsiuni Interioare 12:51
• 2026-10-11Watts says aliasing errors are not harmonically related to the signal, confuse the brain's pitch tracking and degrade transient timing; Quartet eliminates aliasing unlike standard pro ADCs. Distorsiuni Interioare 13:35
• 2026-10-11Watts says Quartet includes a pulse array ADC so vinyl can be recorded, making it a digital preamp; finishing required perfecting this discrete ADC with flash ADCs and integrators. Distorsiuni Interioare 15:29
• 2026-10-11Watts says his research from 2018 asked how many taps give subjectively perfect reconstruction, and why his five-variable WTA coefficient formula had a sweet spot. Distorsiuni Interioare 17:04
• 2026-10-11Watts says aliasing matters because out-of-band signal-correlated noise degrades transient timing, and Quartet's DSD decimation follows its ADC decimation process. Distorsiuni Interioare 56:10
• 2026-10-11Watts says the improvement comes from Quartet's 18 kHz HF filter transparently removing out-of-band noise and signal-correlated distortion, improving transient timing; he had expected digitization to sound worse. Distorsiuni Interioare 1:14:52
• 2026-10-11Watts says he cannot discuss future development, but Quartet puts DAVE in a different league musically, as shown when a prototype was shown at Munich just over 2 years ago. Distorsiuni Interioare 1:17:34
• 2026-10-14Watts says ESS chips have half a dozen filters and at most a few hundred taps, versus 4 million on Quartet and, he thinks, about 44 thousand on Mojo 2. Part-Time Audiophile 33:10
• 2026-10-14Watts says the ADC has been a background project since 2016; hearing the pulse array ADC built into Quartet's analog input made him wish he had done it years earlier. Part-Time Audiophile 50:30
• 2026-10-14Watts says his big project has been Quartet, the 4 million tap upsampler. Part-Time Audiophile 52:29
• 2026-10-14Watts says Quartet began about 8 years ago after the 1 million tap Hugo M Scaler, which guarantees 16-bit accurate reconstruction; 6 years of research went into improving interpolation filters. Part-Time Audiophile 52:36
• 2026-10-14Watts says Blackbird WTA with 4 million taps consumed most of his time; the next big project is the pro audio ADC, with others including the very high-end Ultima DAC. Part-Time Audiophile 53:34
• 2026-10-14Watts says DAVE and Mojo are his most famous, Mojo for audiophile performance at a phone-like price, but Quartet is his most important design, partly for its built-in ADC. Part-Time Audiophile 1:03:03
• 2026-10-14Watts says Quartet solved interpolation filters for him; with the ADC and 768 kHz recordings he can decimate (to '24 kHz' as spoken), re-interpolate and compare, controlling microphone to transducer. Part-Time Audiophile 1:03:53
• 2026-10-17Watts says the female vocalist's pitch reproduction differed greatly: she sounded out of tune on the commercial ADC and in tune on the Quartet ADC. article, Oct 2026
• 2026-10-17Watts says everyone wins because recordings will get better, so you will not need to spend large sums on a Quartet. article, Oct 2026
• 2026-10-17Watts lists transient speed, instruments leaping from dense mixes, timbre variation, soundstage, unpicking many instruments, natural flow, and emotion as improvements, noting listener dependence. article, Oct 2026
• 2026-10-17Watts says to make sure the HF filter is set to 18K. needs context article, Oct 2026
• 2026-10-17Watts says Blackbird WTA improves sinc reconstruction accuracy tenfold, eliminates the other problem and cuts the delay from 900 trillion years to tens of seconds; the algorithm, not four million taps, is the story. article, Oct 2026
• 2026-10-17Watts lists Quartet's hardware problems: heat removal, nine prototypes, over 2,000 components, BNC cables sounding the same, and a supply as good as battery power. article, Oct 2026
• 2026-10-17Watts says budget was not an issue for Quartet, which had to meet technical and sound-quality requirements and then took whatever price resulted. article, Oct 2026
• 2026-10-17Watts says the name Quartet comes from the four million taps. article, Oct 2026
• 2026-10-17Watts confirms it and says they could have called it Quintet but Quartet rings better. article, Oct 2026
• 2026-10-17Watts says Quartet has an analog input. article, Oct 2026
• 2026-10-17Watts says Chord compared a turntable and phono stage direct to a preamp against going through Quartet and DAVE; the digital route sounded a lot better, which puzzled him. article, Oct 2026
• 2026-10-17Watts says Quartet's 18 kHz filter in ADC decimation removes everything above 20 kHz, and that out-of-band noise and distortion are audible because they corrupt transient timing. article, Oct 2026
• 2026-10-17Watts says removing out-of-band noise outweighs the transparency losses of DAVE and Quartet, and an analog filter cannot do it transparently, so analog should stay simple. article, Oct 2026
• 2026-10-17Watts says Quartet with DAVE is the best DAC combination today for emotional engagement and hearing the recording as an original musical event. article, Oct 2026
• 2026-10-17Watts recounts a customer who sold his DAVE hearing a Munich prototype and saying it made DAVE a new category, so he would buy another DAVE. article, Oct 2026
• 2026-10-17Watts says his Mojo 2 4.4 mm connector listening tests used Quartet and it transformed Mojo 2; it works but would not be a sensible pairing. article, Oct 2026
• 2026-10-17Watts says Chord asked for an analog input on Quartet, expecting about 20% more scaler sales, and they weighed a separate ADC against integration. article, Oct 2026
• 2026-10-17Watts says integrating the ADC costs little, a rounding error in the bill of materials beside the FPGA, supplies and metalwork, so the selling price would not change. article, Oct 2026
• 2026-10-17Watts says he doubted the 20% sales claim but it forced Quartet and the ADC to be finished, turning a wish into a required project. article, Oct 2026
• 2026-10-17Watts says he uses the EQ a lot; a ten-band test alternating plus and minus half dB gave no loss in transparency, detail, depth, separation or focus. article, Oct 2026
• 2026-10-17Watts says the EQ at extreme settings passes a minus 301 dB test, phase within a thousandth of a degree and level within a thousandth of a dB, so it is transparent. article, Oct 2026
• 2026-10-17Watts calls one chassis a nightmare because processing noise upsets the DAC; hence separate supplies and a new two-way pinch-off RF filter of about 200 components each. needs context article, Oct 2026
• 2026-10-17Watts says keeping it separate with its own supplies avoids the issue, and he compared against a large lithium-ion battery, meeting his target of equal sound quality. article, Oct 2026

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