Hugo (original): everything he said

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

• 2014-04-01Watts says Hugo seems to sound better over months, possibly his brain adapting, but tests of old versus new units show little difference; DoP is decoded on all inputs. Head-Fi, Apr 2014
• 2014-04-01Watts says Hugo decodes DoP after input selection, and its FPGA SPDIF receiver should run at 384 kHz, untested on hardware, allowing DSD128 over coax once sources exist. Head-Fi, Apr 2014
• 2014-04-01Watts declines a suggested source project as a major effort with no sound-quality gain, noting some Hugo IP began 30 years ago and Hugo is designed from the gate level. Head-Fi, Apr 2014
• 2014-04-04Watts says John Franks is finalizing a leather Hugo case embossed with Chord Hugo, with a pouch for a phone or source, coming soon. Head-Fi, Apr 2014
• 2014-04-09Watts clarifies that the PSU improvement under discussion is for the AP2 USB, not Hugo, and that Hugo is always powered from its batteries, never from USB. Head-Fi, Apr 2014
• 2014-04-15Watts rejects calling Hugo a DAC with a good headphone amp, defines transparency against live music, recounts Hugo's development, and explains its single-stage output, 0.075 ohm impedance and tap length. Head-Fi, Apr 2014
• 2014-04-15Watts says Hugo's output is limited to 5V RMS: 22 ohm or higher loads are fine until white volume, 8 ohms distorts at ultraviolet; HD800 at white was deafening. Head-Fi, Apr 2014
• 2014-04-15Watts says Hugo's DAC is a pulse array with a 104 MHz noise shaper, the DPLL eliminates source jitter, and more taps keep helping, guessing 1M taps for 16-bit accuracy. Head-Fi, Apr 2014
• 2014-04-16Watts compares QBD76's 16-element pulse array with Hugo's 4, says a replacement is in work, and recounts how QBD76 development reshaped the WTA filter to 18k taps. Head-Fi, Apr 2014
• 2014-04-16Watts leaves Hugo plugged in and on permanently, and says the QBD76 replacement will be ready when perfected; he has prototypes and is chasing FPGA timing closure on many taps. Head-Fi, Apr 2014
• 2014-04-16Watts compares PCM and DSD strengths and weaknesses, says a long filter fixes PCM timing while DSD loses low-level detail, and explains why Hugo filters DSD to PCM. Head-Fi, Apr 2014
• 2014-04-16Watts says he consults on custom silicon and designs for Chord using his IP, and explains why FPGAs suit low-volume high-end designs like Hugo better than custom chips. Head-Fi, Apr 2014
• 2014-04-16Watts says any input supports DoP, he heard no difference between glass and plastic optical on red-book, but glass may be needed if DoP at 176.4k is unreliable. Head-Fi, Apr 2014
• 2014-04-17Watts says Qute and Hugo use isochronous USB with timing from the DAC, so reported sound differences are not jitter but RF noise, sounding like reduced noise floor modulation. Head-Fi, Apr 2014
• 2014-04-17Watts says he has not tried many sources, uses a regular laptop on the go, and finds Hugo sounds like Hugo whatever the source, though not from AB tests. Head-Fi, Apr 2014
• 2014-04-17Watts says FPGA progress may allow 10M taps in ten years, stresses that he has argued for tap length and timing since DAC64, against a high-end focus on pre-ringing. Head-Fi, Apr 2014
• 2014-04-17Watts relays Chord's Matt that aptX is much better than standard Bluetooth, which sounds noisy because of its low data rates. Head-Fi, Apr 2014
• 2014-04-17Watts says the tap length is set by the FPGA, reached through many iterations to fit and meet timing while leaving resources for other functions. Head-Fi, Apr 2014
• 2014-04-17Watts says Hugo has five filters: two WTA stages (first 26k taps) to 16FS, a linear interpolator to 2048FS, two IIR filters; the new QBD filter just meets timing. Head-Fi, Apr 2014
• 2014-04-18Watts explains Hugo's volume preset mode came from matching Qute for comparisons, and that the settings-memory feature was dropped because the FPGA was full after adding crossfeed and DSD. Head-Fi, Apr 2014
• 2014-04-26Watts explains Hugo noise with Bluetooth sources as amplitude-modulated 2.4 GHz picked up by headphone cables, and suggests looping the headphone cable through solid or split ferrite cores. Head-Fi, Apr 2014
• 2014-04-26Watts says the headphone noise seems tied to low-impedance headphones and the USB source, notes 33 ohm tested fine, and proposes comparing via the RCA output. needs context Head-Fi, Apr 2014
• 2014-04-27Watts explains why native DSD inside a DAC is a bad idea, recounting PDM1024 and pulse array history, and details Qute's DSD filter and Hugo's 140 dB decimation filter. Head-Fi, Apr 2014
• 2014-04-28Watts suggests the hiss may be master tape noise on older recordings, and says AAC streams sound surprisingly good on Hugo, which he calls a format leveler. Head-Fi, Apr 2014
• 2014-04-28Watts says Hugo drove horn loudspeakers loud and transparently; speakers must be 8 ohms or more and efficient given 1W, below ultraviolet volume; he is busy with the QBD upgrade. Head-Fi, Apr 2014
• 2014-04-29Watts says he uses one Hugo into small active speakers and another feeding his power amp, and advises avoiding pre-amps unless analog sources are needed. Head-Fi, Apr 2014
• 2014-04-29After a joke, Watts reports a microphonics test: board tapping was not badly microphonic, tapping the crystal oscillator gave noise at -115dB, so vibration should not matter. Head-Fi, Apr 2014
• 2014-05-09Watts explains Hugo mutes on data or sample-rate changes to hide garbage from badly behaved software, costing about half a second, and says resets are computer driver failures. Head-Fi, May 2014
• 2014-05-13Watts says Hugo's USB chip takes timing from the FPGA, but the DPLL makes that minor; input differences come from RF noise causing noise floor modulation, so he prefers optical. Head-Fi, May 2014
• 2014-05-13Watts lists ways RF noise enters, says many audiophile cables are RF-poor, some like noise floor modulation's brightness, and advises digital connections with good RF performance. Head-Fi, May 2014
• 2014-05-16Watts credits Hugo's 26,368 WTA taps for its timing, says more taps should help further, and suggests hi-res can underperform red-book because ADC out-of-band noise causes noise floor modulation. Head-Fi, May 2014
• 2014-05-16Watts says leaving it plugged in has no significant effect on sound quality, based on his listening tests. Head-Fi, May 2014
• 2014-05-17Watts says each volume color covers 3 steps of 1dB, a compromise between range and distinguishable colors. Head-Fi, May 2014
• 2014-05-17Watts says the volume steps are in dB, so two colors double or halve the output, giving the same resolution whatever the headphone sensitivity. Head-Fi, May 2014
• 2014-05-19Watts says charger sound depends on RF noise, he hears no difference in trickle charge, Hugo runs from the battery when plugged in, and repairs go through Chord or distributors. Head-Fi, May 2014
• 2014-05-21Watts contrasts four active stages in a conventional DAC with Hugo's single I/V stage with discrete output, and four passive parts in the signal path, enabled by 2048x oversampling. Head-Fi, May 2014
• 2014-05-22Watts says the digital volume control is precise in dB, so a low volume setting with IEMs makes no difference. Head-Fi, May 2014
• 2014-05-22Watts explains FIR taps and WTA coefficients, says perfect reconstruction needs infinite taps, and that Hugo's 26,368 taps run on 16 parallel DSP cores at 208 MHz. Head-Fi, May 2014
• 2014-06-01Watts says higher rates improve timing but admit ADC noise-shaper HF noise causing noise floor modulation; Hugo's 26k-tap filter shrinks the timing gain; he considers a PCM HF filter. Head-Fi, Jun 2014
• 2014-06-01Watts says all files sound better on Hugo, but the relative balance between formats differs on DACs with WTA filters. Head-Fi, Jun 2014
• 2014-06-02Watts relays that Android DSD may be fixed soon, says Hugo's DSD filter uses two custom DSP cores and converts DSD back to DXD, beyond computer converters. Head-Fi, Jun 2014
• 2014-06-02Watts says Hugo in essence converts DSD back to the original DXD master with the DSD HF distortion and noise removed. Head-Fi, Jun 2014
• 2014-06-02Watts calculates Hugo's delay: 26,368 taps over 8x oversampling gives 1,648 samples group delay, 34 mS at 48 kHz, so home theater users may need to reduce video delay. Head-Fi, Jun 2014
• 2014-06-02Watts says DSD64 and DSD128 HF noise must be filtered digitally, criticizes judging Hugo's decimation in theory, and says he AB tested it against a non-decimating filter. Head-Fi, Jun 2014
• 2014-06-02Watts says bit depth does not affect delay but doubling sample rate quarters it, since the first stage always upsamples to 8FS. Head-Fi, Jun 2014
• 2014-06-09Watts cites his 1980s mains cable work, says AB tests found no significant difference with Hugo's charger connected, and describes its PSU of batteries, 9 regulators and 12 RF filters. Head-Fi, Jun 2014
• 2014-06-09Watts says the battery stays connected as a 0.1 ohm low-noise source, the charger path has regulation and RF filtering, and he AB tested to confirm no audible downside. Head-Fi, Jun 2014
• 2014-06-09Watts revises himself: his PSU test was at line level, but the external PSU sounded better with Hugo driving 8 ohm loudspeakers, by supporting battery voltage. Head-Fi, Jun 2014
• 2014-06-09Watts says there are two 2.2AH Li-ion cells; driving 8 ohm loads flat out sags the voltage, so the charger makes it sound fuller. Head-Fi, Jun 2014
• 2014-06-09Watts measures 2.996V RMS at 0dBFS in preset mode and 2.112V RMS at violet, and advises feeding power amps directly without a pre-amp. Head-Fi, Jun 2014
• 2014-06-09Watts says USB affects sound via jitter and RF noise; Hugo solves jitter internally, add-on USB units add RF noise though isolation may help. Head-Fi, Jun 2014
• 2014-06-10Watts corrects that taps belong to the FIR oversampling filter, not the DAC section, and says Hugo's tap length is two orders of magnitude above conventional silicon DACs. Head-Fi, Jun 2014
• 2014-06-11Watts explains that a fully depleted Hugo battery charges at very low current, too little to run the FPGA, then switches to full charge mode; it is safe. Head-Fi, Jun 2014
• 2014-06-19Watts compares Pink Floyd 'Wish You Were Here' on CD and DSD via Hugo; CD had better depth, separation and rhythm, scoring 2-0 to CD. Head-Fi, Jun 2014
• 2014-06-19Watts describes Hugo's three charging modes and says leaving it on with the charger connected gives zero net battery current while keeping low-noise battery operation. Head-Fi, Jun 2014
• 2014-06-19Watts says leaving it plugged in extends battery life, he hears no difference with the charger connected, and dissipation is well below 2W. Head-Fi, Jun 2014
• 2014-06-19Watts says he is about to test USB isolators, aims for Hugo to work with any bit-perfect source, uses regular USB cables in his office and optical at home. Head-Fi, Jun 2014
• 2014-06-19Watts gives Hugo battery temperature ratings (45 deg C charging, 60 discharging), 2W dissipation and 3.2 deg C per W, and advises charging with nothing on top. Head-Fi, Jun 2014
• 2014-06-21Watts says the poster's setup is no problem for Hugo and the wiring is fine, and advises against using a pre-amp. needs context Head-Fi, Jun 2014
• 2014-06-21Watts advises feeding Hugo directly to sub and power amp; active pre-amps add distortion and noise floor modulation, passive controls add wiper and dielectric absorption problems. Head-Fi, Jun 2014
• 2014-06-22Watts re-tests optical vs coax on Hugo, finds optical warmer with better separation, and explains how RF-induced noise floor modulation harms separation and timbre. Head-Fi, Jun 2014
• 2014-06-24Watts says Hugo's SD USB input loses no performance despite not being isochronous, because Hugo's jitter elimination works, and his isolator has arrived. Head-Fi, Jun 2014
• 2014-06-24Watts reports the 33-pound Olimex USB-ISO on Hugo's SD USB input (44.1/48 kHz only) gives better depth, focus and separation, consistent with better RF isolation. Head-Fi, Jun 2014
• 2014-06-25Watts suggests USB isolation also removes signal-dependent ground noise from the computer, which, unlike RF noise, can change perceived sound stage depth. Head-Fi, Jun 2014
• 2014-06-26Watts advises sending 24/192 natively to Hugo despite its ADC noise-shaper noise, warning that PC sample-rate conversion degrades timing; one PC converting to 48 kHz sounded awful. Head-Fi, Jun 2014
• 2014-07-02Watts rebuts a poster: he consults for silicon companies, Hugo's 16 cores at 208 MHz dwarf ASIC DACs, and FFTs at -40 and -140 dB show no distortion or NFM. Head-Fi, Jul 2014
• 2014-07-03Watts says Hugo digitally filters to 9.6nS resolution, adding 2048 new samples, and that 4uS is only the ear's inter-aural delay resolution. Head-Fi, Jul 2014
• 2014-07-07Watts says the Shure SE846's very high sensitivity (114dB 1mW 9 ohms) means some hiss from Hugo, and suggests trying its in-line attenuator. Head-Fi, Jul 2014
• 2014-07-10Watts says a prototype unused for months turned on fully charged at blue, and a unit switched off should not discharge in 24 hours. Head-Fi, Jul 2014
• 2014-07-10Watts says Hugo over-voltage protection failures came from non-supplied, too-high-voltage chargers; a damaged unit goes back to the dealer, and other PSUs bring no sound benefit. Head-Fi, Jul 2014
• 2014-07-21Watts warns that the 12.8V Red Wine Audio Black Lightning battery supply may damage Hugo's input protection, which triggers at that voltage. Head-Fi, Jul 2014
• 2014-07-26Watts says Hugo outputs up to 5V RMS with a 3V preset, advises dropping the pre-amp, and describes damping-factor tests and Hugo's 0.075 ohm output impedance. Head-Fi, Jul 2014
• 2014-07-26Watts says live acoustic music, not analog tape, is the reference, and that DSD is limited: his noise shaper tests improved up to ten trillion times DSD's resolution. Head-Fi, Jul 2014
• 2014-08-03Watts says he always pushes for better performance and expected Hugo to be better, but not revolutionary. article, Aug 2014
• 2014-08-03Watts calls Hugo an accident: over 6 years he had replaced all the digital module code intended for a reference-class DAC. article, Aug 2014
• 2014-08-03Watts says John Franks saw a market for a portable DAC amp, the project began in autumn 2012, and the Spartan-6 LX9 FPGA let Hugo take the reference DAC's code. article, Aug 2014
• 2014-08-03Watts answers 'knowledge': cost limits the capacity of audio chips he designs IP for, while an FPGA removes that bottleneck at higher cost but still needs expertise. article, Aug 2014
• 2014-08-03Watts says he is not a Red Book fan as such, but Hugo handles its problems better; he has heard very good DSD from '70s analog tape, and awful DSD. article, Aug 2014
• 2014-08-03Watts sees speaker-driving DACs with single global feedback to the digital domain as next; Hugo is a 1W digital amp; he has worked on digital power amps for ten years. article, Aug 2014
• 2014-08-03Watts relays his family's answers (panda, duck, sloth) and picks a butterfly for its detailed symmetrical patterns, color variation and rapid, delicate movement. article, Aug 2014
• 2014-08-03Watts describes being astonished by the Hugo prototype versus his Qute: far more musical, no fatigue, revealing without forcing detail, fast rhythm, piano notes starting and stopping naturally. article, Aug 2014
• 2014-08-03Watts says Qute is technically very similar to Hugo yet Hugo is radically different musically, and he is unsure why. article, Aug 2014
• 2014-08-20Watts explains chip DACs are differential for substrate and reference noise reasons, while Hugo is fully single-ended with one output stage, so balanced adds complexity. Head-Fi, Aug 2014
• 2014-08-21Watts says Hugo needs no external amp (HD800 reaches 115dB SPL before clipping), and cites an HMX demo showing added harmonic distortion softens sound but flattens staging. Head-Fi, Aug 2014
• 2014-08-29Watts says FPGA DAC design is far harder than using chips, his Verilog RTL serves ASIC or FPGA alike, and Hugo reflects a six-year upgrade of FPGA modules. Head-Fi, Aug 2014
• 2014-08-30Watts says standard upsamplers have too few taps, so let Hugo do it; the exception is Red Reference's 18K WTA 4x upsampler, equivalent to 36,864 Hugo taps. Head-Fi, Aug 2014
• 2014-08-31Watts recommends max crossfeed for a hard-panned 1967 album and explains Hugo's crossfeed runs on its own 16FS 48-bit cores using first-order EQ like analog crossfeed. Head-Fi, Aug 2014
• 2014-08-31Watts says with his Noble K10s Hugo's noise is just audible when muted, below background noise, while master tape hiss becomes audible on CDs. Head-Fi, Aug 2014
• 2014-08-31Watts says Hugo's noise is 5uV A-weighted on every unit, with 120.0 dB +/- 0.1dB dynamic range, and a unit with much more should be checked. Head-Fi, Aug 2014
• 2014-09-02Watts says Hugo's 5uV residual noise would be just audible on the very sensitive Shure SE846, noting Hugo supplies 5V RMS and 0.5A RMS. Head-Fi, Sep 2014
• 2014-09-02Watts gives Hugo's volume colors in dB: each color typically covers three 1 dB levels, white covers 0 to +18dB, and the -4dB preset gives 3V RMS to match Qute. Head-Fi, Sep 2014
• 2014-09-02Watts says the manual's 2V RMS preset figure will be corrected to 3V RMS in the next print run. Head-Fi, Sep 2014
• 2014-09-03Watts confirms another poster and lists output voltages at each level, noting Hugo clips at +18dB giving 5.25V RMS maximum. Head-Fi, Sep 2014
• 2014-09-06Watts says a completely flat lithium battery charges at very low current, so charge for several hours with the unit switched off. Head-Fi, Sep 2014
• 2014-09-08Watts says 6 ohm 86dB speakers are too much for Hugo's 0.5A, recommends Hugo over Qute for line use, and describes its Class A discrete hybrid output stage. Head-Fi, Sep 2014
• 2014-09-08Watts reports Chord has seen no Hugo electronic failures from impact damage, crediting glued surface-mount parts and no internal connectors. Head-Fi, Sep 2014
• 2014-09-11Watts says high power-amp gain is still better than adding a pre-amp, and he runs at green to azure into amps needing 1V RMS for full power. Head-Fi, Sep 2014
• 2014-09-13Watts says USB isolation gives smoother sound and better depth by blocking correlated ground noise; two USB cables still join grounds; the new QBD has galvanic isolation. Head-Fi, Sep 2014
• 2014-09-21Watts says Hugo driving Axjet horn loudspeakers gave extraordinary depth, with a solo violin in The Lark Ascending sounding 40 feet away. Head-Fi, Sep 2014
• 2014-09-30Watts advises using USB over optical rather than letting the PC resample, and says decimating 88.2 to 44.1 is easier than upsampling as decimation has no timing problems. Head-Fi, Sep 2014
• 2014-10-01Watts says USB cables change sound through RF noise causing NFM and brightness, while signal-dependent ground currents degrade depth; galvanic isolation addresses both. Head-Fi, Oct 2014
• 2014-10-01Watts says the Olimex breaks Hugo's HD USB negotiation but makes the SD input smoother, and suspects it uses the Analog Devices isolator chip with 2pF coupling. Head-Fi, Oct 2014
• 2014-10-08Watts discusses Hugo's low fatigue and prototype surprise, says the source matters little via optical, hears no plastic vs glass difference, and mentions Chord projects nearly ready. Head-Fi, Oct 2014
• 2014-10-09Watts says there are no plans for a portable Hugo Mk 2, but Hugo-type sound with power to drive loudspeakers directly is in development. Head-Fi, Oct 2014
• 2014-10-10Watts says he designs for Chord because he wants the products; Chord was 10% of his income during Hugo; Hugo amp targets his office and lounge, with mono-block mode. Head-Fi, Oct 2014
• 2014-10-12Watts says his Olimex tests used a noisy Dell, so an iPhone may need no isolation; smoother sound and better depth indicate lower RF and correlated noise. Head-Fi, Oct 2014
• 2014-10-12Watts says yes if it does not overload or add distortion, notes the attenuator can matter, and suggests trying both and using Hugo's higher output if no difference. needs context Head-Fi, Oct 2014
• 2014-10-20On Hugo's first anniversary, Watts recalls its first listening test, credits a six-year Verilog rewrite and the Spartan-6 FPGA, and says pursuing transparency paid off in musicality. Head-Fi, Oct 2014
• 2014-10-20Watts says Hugo's outputs share one 1W power amp, its only active stage, and that a more powerful 20W-into-8-ohm version of Hugo, from a ten-year project, is being prototyped. Head-Fi, Oct 2014
• 2014-10-25Watts gauges an improvement by how long it stays noticeable, from one day to over three months, rates the Olimex isolator a one-week change, and calls Hugo's break-in mental adaptation. Head-Fi, Oct 2014
• 2014-10-26Watts says the Olimex isolator works only with the SD USB input, not at all on the HD USB input, and only up to 48 kHz. Head-Fi, Oct 2014
• 2014-10-27Watts says RF in Hugo's ground plane causes bright noise floor modulation and zero-crossing currents degrade linearity and depth; the Olimex removes LF currents and matched optical for him. Head-Fi, Oct 2014
• 2014-10-27Watts notes optical runs only to 192 kHz, some transmitters to 96 kHz, and says low-power mobile sources suffer far less from the noise problem than PCs. Head-Fi, Oct 2014
• 2014-10-28Watts says USB 5V only detects a connection and powers the HD USB chip with RF decoupled, USB-to-optical converters should work, and mobile sources are already low-noise. Head-Fi, Oct 2014
• 2014-11-06Watts says Chord has for months built Hugos with new USB connectors soldered top and bottom so they cannot break from the PCB, with no change in sound. Head-Fi, Nov 2014
• 2014-11-10Watts says the charger should stay on while using Hugo because it matches Hugo's current draw, and it shuts down when Hugo is off until the batteries deplete. Head-Fi, Nov 2014
• 2014-11-13Watts says his main system has Hugo driving power amps directly, since removing the pre-amp greatly boosts transparency, though he must get up to change volume. Head-Fi, Nov 2014
• 2014-11-13Watts says Hugo's outputs are connected internally to one stage combining I-to-V and headphone drive, unlike a conventional DAC's several stages, so there is no fixed DAC output to buffer. Head-Fi, Nov 2014
• 2014-11-18Watts says the two sockets exist simply to allow other listeners, and crossfeed is most noticeable on older recordings panned hard left and right. Head-Fi, Nov 2014
• 2015-01-23Watts says Hugo's 51-bit volume is truncated at 16FS by noise shaping and dither, adding only fixed -180dB noise, and notes its output relay, 75 milliohm impedance and anodizing. Head-Fi, Jan 2015
• 2015-01-26Watts says few old-style USB connectors failed and will last if handled gently, and Chord reports no failures among thousands of new-style USB units shipped. Head-Fi, Jan 2015
• 2015-02-02Watts says Hugo was never voiced; he designs for transparency by judging variation in placement, timbre and separation, and recounts how Hugo's musicality after a six-year code upgrade surprised him. Head-Fi, Feb 2015
• 2015-02-02Watts describes TT's floating balanced output, says TT uses batteries for mains isolation though 2Qute proved RF filtering matches it, and lists balanced drive's pros and cons. Head-Fi, Feb 2015
• 2015-02-02Watts says live acoustic instruments are the only absolute reference, judges transparency by range of variation, notes studios adopting Hugo, and uses electronic music to assess timing. Head-Fi, Feb 2015
• 2015-02-15Watts says DSD modulators become unstable above -6 dBFS, so Hugo's DSD filters keep that headroom and internally raise volume by +6 dB to preserve gain. Head-Fi, Feb 2015
• 2015-02-15Watts says DSD should not be quieter on Hugo, since test tones converted to DSD were level-matched to PCM and with the +6 dB boost levels were identical. Head-Fi, Feb 2015
• 2015-02-16Watts contrasts conventional DACs' four active stages with Hugo's single feedback stage using a fast Class A discrete output, leaving two resistors and two capacitors in the signal path. Head-Fi, Feb 2015
• 2015-03-01Watts says short filters cause transient timing errors of tens of microseconds; Hugo uses 26,000 taps, 164,000 still beats 100,000, and about a million taps would give 16-bit accuracy. Head-Fi, Mar 2015
• 2015-03-01Watts says Hugo's WTA filter has 38 ms latency, so interpolation draws on 76 ms of data, and the 164,000-tap filter's latency is much longer. Head-Fi, Mar 2015
• 2015-03-04Watts says FIR filters have no simple dB/octave figure, more taps narrow the gap to hi-res, but poor SRC from 96 kHz masters cannot be undone, so recordings vary. Head-Fi, Mar 2015
• 2015-03-11Watts details Hugo's stages: 26,368-tap WTA from 1FS to 8FS, WTA stage two to 16FS with volume, interpolation to 2048FS, and noise shapers at 104.25 MHz tied to the DPLL. Head-Fi, Mar 2015
• 2015-03-13Watts says Project xxxx's headphone drive has slightly more voltage and the same current as Hugo, and it cannot be battery powered since its FPGA dissipates 5W. Head-Fi, Mar 2015
• 2015-03-14Watts defends Hugo's color volume display, gives its range from +18 dB (white) to -70 dB (dark brown), prefers digital volume to pots, and says Project xxxx keeps the colors. Head-Fi, Mar 2015
• 2015-03-23Watts says mastering engineers are taking up Hugo because it reveals what is wrong with a recording while conveying what is musically right, his first design to gain both. Audiophile Style, Mar 2015
• 2015-04-06Watts says 24/192 still sounds better than 44.1/16 on Hugo, but its 26,000-tap WTA filter makes the gap much smaller than on other DACs, and AAC can sound surprisingly good. Head-Fi, Apr 2015
• 2015-04-15Watts explains FPGAs, their DSP cores used for interpolation filters, says Hugo's FPGA has 16 DSP cores, 100 times a normal DAC's logic, and an upcoming product's is 1000 times. article, Apr 2015
• 2015-04-15Watts says he assumes nothing about audibility, tests by listening, and pushes each parameter until he hears no difference, which he calls Hugo's big difference from other devices. article, Apr 2015
• 2015-04-15Watts says Hugo TT differs from Hugo in beefier batteries, better reference supply circuitry that reduces noise floor modulation, and galvanic isolation on USB. article, Apr 2015
• 2015-04-15Watts confirms isolation follows the USB chip, which draws PC power, so Hugo lacks it; laptops cause earth-loop and RF problems phones do not, and isolation removes audible laptop differences. article, Apr 2015
• 2015-04-20Watts gives each input's maximum data width and rate (SD USB and Bluetooth 16-bit/48 kHz, HD USB 32-bit/384 kHz, optical 192 kHz, coax 384 kHz) and battery life by input. Head-Fi, Apr 2015
• 2015-04-20Watts explains Hugo's discrete Class A output stage, his path from 1989 PDM DACs to the 16-element pulse array, its jitter immunity, time-domain reconstruction, and R2R's flaws. Head-Fi, Apr 2015
• 2015-04-20Watts says Project xxxx launches at Munich and is unlikely to become a Hugo upgrade, since its improvements need far more FPGA capacity than Hugo has. Head-Fi, Apr 2015
• 2015-04-21Watts says every Hugo he measured shows 120 dB dynamic range within 0.1 dB, but sensitive SE846 earphones will hiss, so use their attenuator. Head-Fi, Apr 2015
• 2015-04-30Watts says maximum unclipped output is a little over 5V RMS into 300 ohms, the 37V figure is just a spreadsheet entry, and pressing crossfeed at power-up sets 3V RMS at 0 dBFS. Head-Fi, Apr 2015
• 2015-05-04Watts says there have been no firmware changes for the black version. Head-Fi, May 2015
• 2015-05-04Watts says there are two 4.2V batteries, giving an 8.4V supply. Head-Fi, May 2015
• 2015-05-16Watts says the light is an authorization indicator showing the FPGA's 512-bit encrypted key matches its unique DNA, which prevents copying Hugo's FPGA. Head-Fi, May 2015
• 2015-05-16Watts says it is impossible because DAVE's large FPGA dissipates 5W against Hugo's 0.8W, needs a machined heatsink, and uses 166 DSP cores for WTA filtering. needs context Head-Fi, May 2015
• 2015-05-20Watts says DAVE stands for Digital to Analogue Veritas in Extremis, explains the name, and says its development built on understanding why Hugo sounded so musical. HIFICLUBE.NET JVH 4
• 2015-05-20Watts says that tuning Hugo, better noise shaper performance improved perceived depth, limited by Hugo's gates; for DAVE he began listening tests from Hugo's roughly 200 dB. HIFICLUBE.NET JVH 5:32
• 2015-06-06Watts says the unit is not class D: like Hugo, a single-stage amplifier drives line and headphone outputs, giving 6v RMS with the same 0.5A RMS current as Hugo. needs context Head-Fi, Jun 2015
• 2015-06-18Watts explains the pulse array's analog-like distortion, why half-band filters keep original samples, and how a 256-tap WTA beat a 2048-tap half-band Kaiser filter in the late 90s. Head-Fi, Jun 2015
• 2015-06-18Watts says half-band filters time transients poorly (-6dB at FS/2); 16-bit sinc accuracy needs about 1M taps; Hugo is about 12 bits, Dave about 14. Head-Fi, Jun 2015
• 2015-07-19Watts says optical is the best input on Hugo. Head-Fi, Jul 2015
• 2015-07-19Watts reports APx555 measurements showing identical dynamic range across Hugo's inputs, optical slightly worse THD despite sounding better, and no source jitter artifacts down to 500 fS. Head-Fi, Jul 2015
• 2015-08-01Watts says Dave, like Hugo, uses the same output for headphones and line level; XLR gives up to 12v RMS but is not for headphones; RCA gives 6v RMS. Head-Fi, Aug 2015
• 2015-08-17Watts says Hugo's FPGA code has not changed during production, so there are no multiple versions. Head-Fi, Aug 2015
• 2015-08-29Watts says the calibrated output began as a prototype feature for listening tests against earlier DACs set to exactly 3v RMS at 0 dBFS, and was kept for DAC mode. Head-Fi, Aug 2015
• 2015-09-02Watts recommends the Nighthawks for a warm, smooth yet transparent sound and says adding external amps to Hugo will always degrade transparency. Head-Fi, Sep 2015
• 2015-09-14Watts says Hugo is FPGA limited, so lessons from Dave cannot be applied; Dave may be upgradable via Chord or the distributor, only for a clear subjective improvement. Head-Fi, Sep 2015
• 2015-09-25Watts argues DSD is flawed by its format: limited noise-shaper resolution loses small signals and depth, and level-dependent timing non-linearity softens transients and compresses timbre. Head-Fi, Sep 2015
• 2015-10-03Watts says pulse array's constant switching makes it immune to jitter, and USB purifiers are pointless for galvanically isolated Dave, Hugo TT and 2Qute; Hugo's issue is RF noise. Head-Fi, Oct 2015
• 2015-10-03Watts criticizes uncritical acceptance in high-end audio, recounts leaving audio after DAC64 in 2001 for silicon work, and says Hugo's success led him back full time. Head-Fi, Oct 2015
• 2015-10-06Watts says Dave uses one FPGA with ten times Hugo's capacity, drawing 5A, is still a work in progress, and has PCM+ and DSD+ programs, DSD+ offering lower latency. Head-Fi, Oct 2015
• 2015-10-06Watts says Hugo and 2Qute will get no upgrades; Dave could be upgraded via distributor or Chord only for a substantial gain, which is less likely as his technology matures. Head-Fi, Oct 2015
• 2015-10-11Watts says Hugo driving efficient horn speakers directly beats feeding a linear power amp, which motivated the Hugo amp project: Hugo simplicity with a linear output stage giving enough power. Head-Fi, Oct 2015
• 2015-10-30Watts says Dave's depth, about four times Hugo's, comes from small-signal accuracy of its -350 dB noise shapers; timing gains offset the darkness that reducing noise floor modulation brought. Head-Fi, Oct 2015
• 2015-11-10Watts says Dave's key gain is timing: WTA filtering to 256FS reconstructs timing to 88 nS, improving starting and stopping of notes, while depth comes from the noise shapers. Head-Fi, Nov 2015
• 2015-11-13Watts says Dave gives 6.75 V RMS at 1% THD, suggests demoing it with Abyss headphones he has not tried, and says production code is close. Head-Fi, Nov 2015
• 2015-11-21Watts explains Dave's DSD filtering, how out-of-band noise causes noise floor modulation heard as brightness, the 60 kHz HF filter helping even CD, and PCM+ versus DSD+ modes. Head-Fi, Nov 2015
• 2015-11-22Watts recounts developing Dave: smoothness from reduced noise floor modulation, Hugo-derived timing gains from 256FS WTA (88nS), and noise shapers raised from 200 to 350 dB for depth. Head-Fi, Nov 2015
• 2015-12-01Watts ties depth to small-signal linearity, distinguishes it from noise floor modulation, and describes raising Dave's noise shapers from 200 to 350 dB with depth improving throughout. Head-Fi, Dec 2015
• 2015-12-11Watts defines musicality as emotional involvement, achieved by reducing errors the brain cannot decode: timing (long taps), small-signal accuracy for depth (2048FS noise shapers), and noise floor modulation. Head-Fi, Dec 2015
• 2015-12-28Watts says with the charger connected Hugo's batteries get current matching its draw, so they last long; other numbered replies say 'it' is not working and to contact Chord. needs context Head-Fi, Dec 2015
• 2015-12-29Watts says all connectors loosen with time, the 9mm one is fine, and the gold-plated switch is rated at 10,000 operations; he kept his on until Dave replaced it. Head-Fi, Dec 2015
• 2015-12-30Watts says Dave is better than Mojo/Hugo, but Hugo was the first digital device that let him enjoy music rather than sound, despite being technically close to Qute. Head-Fi, Dec 2015
• 2016-01-04Watts explains that source differences heard with Hugo came from RF noise (noise floor modulation heard as brightness) and correlated ground currents degrading depth, which Dave's galvanic isolation removes. Head-Fi, Jan 2016
• 2016-01-09Watts says the Mojo project grew out of Hugo and its success, and that Hugo began as a fun exercise for himself. What Hi-Fi? 7:06
• 2016-01-09Watts says he made Hugo while designing silicon chips in Phoenix, and was surprised studios use it for mixdown: seventy percent of the UK's top one hundred is heard through Hugo. What Hi-Fi? 7:25
• 2016-01-11Watts says TT beats Hugo via supercaps lowering PSU impedance, heavier metalwork, USB galvanic isolation and a better flip-flop reference supply that cuts distortion and noise some 4 dB. Head-Fi, Jan 2016
• 2016-01-18Watts says the target is no out-of-band noise; Hugo is 50 kHz -3 dB, with no measurable noise from 23 to 50 kHz on CD; 1 MHz noise matters more. Head-Fi, Jan 2016
• 2016-01-21Watts says Dave's FPGA has 132 DSP slices plus 34 fabric cores, his DACs reject source jitter equally, and source differences come from RF and correlated noise, removed by isolation. Head-Fi, Jan 2016
• 2016-01-24Watts compares 2 Qute and Hugo: similar on optical or coax, 2 Qute's galvanic isolation helps with a PC on USB, Hugo can feed power amps directly; output stages match. Head-Fi, Jan 2016
• 2016-01-25Watts says he left his Hugos on all the time and that at about 1.5W the power draw is nothing to worry about. Head-Fi, Jan 2016
• 2016-01-27Watts says linear supplies involve compromises: developing Hugo in 2012, switching regulators sounded smoother with deeper soundstage and measured better than linear ones, so assumptions must be tested. Head-Fi, Jan 2016
• 2016-01-29Watts says Hugo's noise shaping was limited by its four-element pulse array and FPGA; for DAVE each 20 dB improvement from 200 dB deepened the stage, reaching -350 dB. article, Jan 2016
• 2016-01-29Watts says a single-stage 16FS WTA first stage sounded much better, by more than 26,000 versus 164,000 taps, and 256FS second-stage filtering improved timing accuracy from microseconds to nanoseconds. article, Jan 2016
• 2016-01-29Watts says Hugo development has stopped because its FPGA is too small, and that after he improved DAVE's WTA filters it sounds faster, tighter, more dynamic, neutral and transparent. article, Jan 2016
• 2016-01-29Watts explains that Hugo's sound hardened into low-impedance headphones, and that treating the output stage as a second-order analog noise shaper with nested feedback removed the distortion change at 32 ohms. article, Jan 2016
• 2016-02-16Watts says Hugo's perception of timing, the starting and stopping of notes, surprised him, and Dave was about identifying and maximizing that factor, which he now understands technically. Head-Fi, Feb 2016
• 2016-02-18Watts says the crossfeed settings are 0 for none, 1 minimum and 3 maximum, the same as Hugo. Head-Fi, Feb 2016
• 2016-03-04Watts says the intended price is nearer TT than Dave, and wishes Hugo were closer to Dave in sound so he need not carry Dave, now at 150,000 miles. needs context Head-Fi, Mar 2016
• 2016-03-07Watts is quoted: developing Hugo in 2013 he thought 1 microsecond accuracy was enough, but developing DAVE he confirmed nanosecond-level accuracy has an effect. article, Mar 2016
• 2016-03-07Watts says ordinary DAC ICs use 100 taps at 8x or 16x; the article gives DAVE 164,000 taps at 256fs on 166 DSPs, and DAC64 1,000, QBD76 18,000, Hugo 26,000 taps. article, Mar 2016
• 2016-03-29Watts says AB tests struggle to tell transparency from noise floor modulation, that better noise shapers in DAVE improved depth, and that Verilog simulation can quantify very small errors. Head-Fi, Mar 2016
• 2016-04-22Watts says he listens to BBC Radio 3 at 320k AAC at home and a 4 TB drive away, and that Hugo first made poor recordings musically enjoyable. Head-Fi, Apr 2016
• 2016-05-09Watts says fully depleted batteries put Hugo in safety charge mode and gives a reset procedure: switch off, disconnect the charger 10 seconds, reconnect, and charge overnight with Hugo off. Head-Fi, May 2016
• 2016-05-13Watts says high-speed internal switchers sounded smoother and warmer than linear regulators in Hugo, forced more RF filtering, and cut DAVE's FPGA supply current from 5 A to 1 A. Head-Fi, May 2016
• 2016-05-17Watts explains DSD's and PWM's switching, jitter and amplitude-timing errors, how pulse array balances switching to avoid them, and why DAVE needs 350 dB noise shapers for depth. Head-Fi, May 2016
• 2016-05-24Watts states that Hugo accepts DSD via DoP only. Head-Fi, May 2016
• 2016-06-10Watts says R2R DACs create large amounts of distortion that their fans like, whereas he wants un-amplified music as in the original acoustic, which Hugo brought him closer to. Head-Fi, Jun 2016
• 2016-06-13Watts suggests the unit may be in safety charge mode and gives a reset and overnight charge; if still flashing, contact the dealer, as a failing charger can cause it. Head-Fi, Jun 2016
• 2016-06-22Watts says the unit sounds like it needs service, and that optical at 192k needs a low-loss cable: 0.25M plastic should work, longer runs need quality glass fiber. Head-Fi, Jun 2016
• 2016-07-24Watts says a second factor behind DAVE was the unexpected quality he heard from Hugo, whose internal digital modules had been upgraded over a 6 year period. Hifistatement 32
• 2016-07-24Watts says a major code rewrite, with more powerful simulation tools, was intended for a planned reference DAC; he made Hugo for hotel listening, expecting few sales. Hifistatement 1:17
• 2016-07-24Watts says Hugo was a personal project while he did silicon design work in Phoenix; code developed for the reference product went into Hugo, the first product using it. Hifistatement 2:03
• 2016-07-24Watts says Hugo did things he had never heard from digital, especially on piano: each key being pressed and the timbre changing with touch, where before it sounded muddled. Hifistatement 2:46
• 2016-07-24Watts says Hugo's quality came from perceiving the starting and stopping of transients, not the WTA filter, since earlier 32,000-tap filters lacked it (Hugo had 26,000); DAVE gets bigger FPGAs. Hifistatement 3:31
• 2016-07-24Watts says Hugo is cost constrained while DAVE's FPGA is 10 times larger, allowing longer taps, bigger WTA filters, more advanced noise shapers and a better discrete pulse array DAC. Hifistatement 4:16
• 2016-07-24Watts says Hugo has about 26,000 taps, Mojo similar, and DAVE 164,000 taps on 166 DSP cores filtering to 2048 times; the 100,000-line WTA code repeatedly failed timing closure. Hifistatement 3:15
• 2016-07-24Watts says the DAVE filter took nine months to work on the FPGA, and was better but lacked Hugo's starting and stopping of notes, speed and timbre variation. Hifistatement 4:02
• 2016-07-24Watts says changing the noise shaper while optimizing Hugo made a large, easily heard difference to depth perception, which audio reproduces badly, citing a cathedral organ 100 meters away. Hifistatement 0
• 2016-07-24Watts says Hugo's noise shaper reached around 200 dB, about a thousand times more resolving power than normal high-end noise shapers, and describes his silicon IP business, stopped weeks earlier. Hifistatement 58
• 2016-07-24Watts says dithered PCM keeps small signals within the noise, but noise shapers cannot be dithered properly and discard them; Hugo's 4E pulse array and gate count limited it. Hifistatement 2:23
• 2016-07-24Watts says for DAVE he raised noise shaper performance from Hugo's 200 dB through 220, 240 and 260 dB, depth improving each time, reaching -350 dB over 90 days. Hifistatement 3:05
• 2016-07-24Watts says redesigning DAVE's all-digital noise shapers to 350 dB gave the same results, so the digital path truly needs 350 dB (48-bit) accuracy; it is not a proxy. Hifistatement 5:24
• 2016-07-24Watts says better 2048FS filtering on Hugo also improved timing resolution, so in place of Hugo's 8x-then-16x WTA stages he tried a single 16x WTA stage, which sounded a lot better. Hifistatement 6:51
• 2016-07-24Watts says this mattered more than going from 26 thousand to 164 thousand taps, 16x filtering is accurate only to microseconds, and he added a 16x-to-256x WTA stage. Hifistatement 7:47
• 2016-07-24Watts says Hugo cannot be improved because its FPGA is too small, its design is optimal for that device, and DAVE's 16FS and 256FS gains came from far more processing. Hifistatement 10:57
• 2016-07-24Watts says analog and noise shaper improvements made DAVE almost too rich and soft, lacking Hugo's immediacy, until improved WTA filters and other changes made it faster, tighter, more dynamic and more neutral. Hifistatement 11:45
• 2016-07-24Watts says Hugo's sound hardened slightly into very low impedance headphones, with higher-order harmonics measurable; since an analog amplifier is a first-order noise shaper, he took a second-order approach. Hifistatement 0
• 2016-08-19Watts hypothesizes that brain break-in, first noticed with Hugo, is the brain unlearning coping strategies for sampled-data timing errors, which DAVE showed must be accurate to nanoseconds. Head-Fi, Aug 2016
• 2016-10-05Watts blames SMPS leakage switching currents in the ground upsetting an amp with poor common mode rejection, avoidable by earthing Hugo via the coax input or using battery mode. Head-Fi, Oct 2016
• 2016-10-18Watts says he only appreciated hearing notes start and stop with Hugo three years earlier, and that accurate depth and sharp transients are key to approaching live sound. Head-Fi, Oct 2016
• 2016-10-20Watts lists the filter stages: Hugo and Mojo use WTA 16FS, linear interpolation to 2048FS and 260 kHz low-pass filters; DAVE adds a WTA stage to 256FS, nearer ideal sinc. Head-Fi, Oct 2016
• 2016-12-08Watts says the quoted figures are nonsense and begins to give Hugo's actual output, but the figures that followed are missing from the record. needs context Head-Fi, Dec 2016
• 2016-12-09Watts says HD800S gives 90dB SPL at 0.22v RMS, so 116 dB SPL from Hugo; much of external amps' supposed benefit is added distortion; he suggests EQ or Nighthawks. Head-Fi, Dec 2016
• 2017-01-09Watts says WTA processing is identical from 44.1 to 384 kHz, explains mounting the FPGA core switching regulator underneath to limit ground-plane noise, and Blu Mk2 needing 12A. Head-Fi, Jan 2017
• 2017-01-23Watts says the 256FS filter improves starts and stops of notes, Hugo cascaded two WTA stages while Dave uses one, and Dave remains well above Hugo 2. Head-Fi, Jan 2017
• 2017-02-07Watts says PC upsampling has limited taps and conventional algorithms, converting to DSD degrades depth and timing, and data to Mojo, Hugo or Dave should stay bit perfect. Head-Fi, Feb 2017
• 2017-02-15Watts says few headphones need more power than Hugo gives, he added Hugo 2 filters for a softer option, and doubts digital EQ reaches the 350 dB needed for depth. Head-Fi, Feb 2017
• 2017-02-19Watts says Hugo TT beats Hugo mainly through better references, USB isolation and more Class A bias, the PSU being about 20%, and Hugo drives all headphones below white. Head-Fi, Feb 2017
• 2017-03-05Watts cautions one laptop test proves little: Hugo 1 improved enormously with isolation from a Dell PC, while galvanic isolation on production Blu 2 with DAVE gives a substantial improvement. Head-Fi, Mar 2017
• 2017-03-15Watts posts his CanJam Singapore Hugo 2 slides: WTA2 to 256FS, filter options and advice, DSD filtering, noise shapers and depth, crossfeed, and APx555 measurements showing no noise floor modulation. Head-Fi, Mar 2017
• 2017-04-06Watts reports a USB ground-loop test slightly truncated depth and added brightness; isolation seems unnecessary for headphones, and Hugo 2 is 5 to 10 times less sensitive than Hugo 1. Head-Fi, Apr 2017
• 2017-04-07Watts says Hugo 2 is more incisive, transparent and refined than Hugo 1, crediting lower noise floor modulation, better noise shaping and truncation, and the 256FS WTA. Head-Fi, Apr 2017
• 2017-04-15Watts says Hugo 2's residual noise is 2.6 uV, half of Hugo 1's, making hiss 6 dB quieter; whether it is silent depends on the IEM and listener. Head-Fi, Apr 2017
• 2017-06-08Watts says galvanic isolation mattered greatly on Hugo 1, but Hugo 2's RF filtering and supply isolation (over 144 dB separation) cut its benefit tenfold; he suggests listening to USB versus optical to test sensitivity. Head-Fi, Jun 2017
• 2017-06-17Watts calls Hugo 2 a complete redesign of Hugo 1: better DSD filtering, 10 pulse array elements instead of 4, a second-order analog noise shaper output, digital DC servo. Head-Fi, Jun 2017
• 2017-06-26Watts recounts his DAC history since 1988 and how Hugo, from 2012, made poor recordings musically involving, which he attributes to the ear's sensitivity to reconstruction timing errors. Head-Fi, Jun 2017
• 2017-07-25Watts says Hugo's WTA1 ran 1FS to 8FS at 26,368 taps; Hugo 2's goes 1FS to 16FS at 49,152 taps, then WTA2 to 256FS on white/green. Head-Fi, Jul 2017
• 2017-08-10Watts notes Benchmark's website omits galvanic isolation, disputes that Hugo 1 sounds different, praises its musicality with archive recordings, and says 1960s Decca sounds real via Blu 2 and DAVE. Head-Fi, Aug 2017
• 2017-08-12Watts says he keeps the filter on green, that Hugo 1 let him enjoy poor archive recordings, and advises trusting posts that describe differences in detail over 'different league' claims. Head-Fi, Aug 2017
• 2017-08-21Watts dismisses a quoted claim that Hugo 2 is only slightly better than Hugo 1, answering 'you're having a laugh'. Head-Fi, Aug 2017
• 2017-09-06Watts says crossfeed on Hugo 1 suited only older recordings, but on Hugo 2 it gives better soundstage depth on all recordings. Head-Fi, Sep 2017
• 2017-09-09Watts says Hugo 2's crossfeed code is unchanged from Hugo, but better depth makes crossfeed have a big impact on perceived depth, as also happens with Dave. Head-Fi, Sep 2017
• 2017-09-14Watts says a flashing charge light means the charger detected a timeout or low voltage; reset by removing the PSU for 10 seconds and charge overnight with Hugo switched off. Head-Fi, Sep 2017
• 2017-09-19Watts says crossfeed tames hard-panned early stereo; on Hugo 1 it gave normal recordings no depth benefit, but on Hugo 2 depth is deeper and sounds seem outside the head. Head-Fi, Sep 2017
• 2017-09-19Watts explains headphone depth perception, why Hugo 2 crossfeed gives out-of-head sound, and why small-signal accuracy to -301 dB lets the brain use depth cues. Head-Fi, Sep 2017
• 2017-10-13Watts says tap length is crucial and, with Moore's Law, tap counts rose: DAC64 1,000, QBD76 18,000, Hugo 26,000 and DAVE 164,000. miceblue425 22:51
• 2017-10-13Watts says in DAVE's development he started from Hugo's 26,000-tap filter and designed a 164,000-tap one; two designs failed timing closure, which he explains. miceblue425 28:44
• 2017-10-13Watts disagrees that Head-Fi made Hugo possible, saying Hugo started development when he was only vaguely aware of Head-Fi. Head-Fi, Oct 2017
• 2017-10-20Watts lists WTA tap lengths (DAC64 a thousand, QBD76 18 thousand, Hugo 26,000, DAVE 164,000) and says each increase improved bass definition, timbre, staging precision and note starts and stops. Hifistatement 0
• 2017-10-23Watts says he once heard Beats headphones sound rhythmic, fast and musical, driven by a Hugo 1 hidden under the counter. Head-Fi, Oct 2017
• 2017-10-23Watts says Hugo 2's battery is not bypassed; a regulated boost PSU replaced Hugo's super caps, cutting PSU distortion 10,000 times, and a linear PSU is inaudible with headphones. Head-Fi, Oct 2017
• 2017-10-28Watts says going from Hugo's 26k to DAVE's 164k taps changed little until WTA algorithm tweaks did; for a given algorithm, doubling taps doubles accuracy against the ideal. Head-Fi, Oct 2017
• 2017-12-02Watts calls the reference voltage the key internal supply, explains 2Qute's upgraded regulation and RF filtering, his jitter-removing DPLL, and pulse array jitter tolerance (DAVE 128 to 128.5 dB). Head-Fi, Dec 2017
• 2017-12-05Watts says any small-signal error is audible, recounting that the first Hugo's code was too big to fit, so he slimmed down the noise shaper, worried about sound quality. RMAF 20:51
• 2017-12-05Watts says Hugo's slimmer noise shaper improved only depth, and with DAVE's ten-times-larger FPGA he raised the noise shaper from 200 to 220 dB and depth deepened. RMAF 21:37
• 2017-12-05Watts says skeptics bought Chord and upgraded Mojo to Hugo 2 to DAVE, every DAVE buyer buys a Blu 2, and this first show presentation aims to explain his technology. RMAF 55:28
• 2017-12-05Watts says Hugo was a fun project for hotel listening, expected to sell a couple of hundred, that he designs for interest not money, and refuses some Chord requests. RMAF 57:27
• 2018-01-03Watts says Hugo 1's DSD filter had audible aliasing at -150dB, the new one is better than -240dB, and this work informs Davina, which will make aliasing negligible. Head-Fi, Jan 2018
• 2018-02-07Watts says he cannot say whether someone will like a product, only that Hugo 2 and Qutest are technically, measurably and musically much more advanced than Hugo 1 and 2Qute. Head-Fi, Feb 2018
• 2018-02-14Watts says Hugo 1 and Mojo have similar depth because they share the same pulse array, noise shapers and truncators, which set small-signal linearity and hence depth. Head-Fi, Feb 2018
• 2018-02-16Watts recounts that Qute owners' PSU reports led him to add regulation and RF filters to 2Qute, which then sounded unchanged on a car battery; try a USB battery pack. Head-Fi, Feb 2018
• 2018-02-23Watts recounts DAC64 using four FPGAs and about 15 watts for a thousand taps, then Hugo reaching 26,000 taps with a huge gain; both were 8FS filters. MajorHiFi 10:27
• 2018-02-23Watts says going from Hugo to Dave took nine months of coding yet gave an important but not night-and-day change, so he thought 164,000 taps neared the limit. MajorHiFi 11:29
• 2018-03-11Watts says switchers beat linear regulators on Hugo 1 through lower RF noise, which causes noise floor modulation heard as brightness, and advises trying a USB battery bank first. Head-Fi, Mar 2018
• 2018-03-31Watts says Hugo launched in 2014 as a fun project; he expected to sell a couple hundred but over 10,000 sold, which brought him back to high-end products. article, Mar 2018
• 2018-04-04Watts says he began assembling electronics as a boy, building a matchbox radio for his paper round, and 40 years later designed the portable Hugo from the bottom up. article, Apr 2018
• 2018-04-04Watts lists tap lengths: DAC64 (1999) 1,024, Hugo (2013) 26,000, DAVE (2015) 164,000, Blu MKII (2017) 1,015,808; each increase plus WTA algorithm improvements raised sound quality. article, Apr 2018
• 2018-04-04Watts weighs DAVE, the M scaler (1M taps, a lifetime dream) and Mojo (musicality he has heard from no non-Chord DAC), picks Mojo, and says Hugo most changed his listening. article, Apr 2018
• 2018-04-04Watts says since Hugo bad recordings became enjoyable, concluding the brain copes with noise, harmonic distortion and frequency response but not digital's unnatural distortions. Head-Fi, Apr 2018
• 2018-05-03Watts says pulse array was designed so every unit measures identically, attributes perceived break-in to the brain, notes a slight warming after ten minutes, and says 192k remains inaccurate. Head-Fi, May 2018
• 2018-05-04Watts says his DSD filters reconstruct the analog signal, but DSD's lost timing information cannot be repaired; Hugo 2's improved DSD filter softened his stance though he prefers Redbook. Head-Fi, May 2018
• 2018-06-27Watts says aliasing ruins music: Hugo's -130dB DSD decimation was audible, Hugo 2, TT2 and M scaler reach -220dB, MQA manages -40dB, and 768 kHz needs 24 bits. Head-Fi, Jun 2018
• 2018-07-21Watts lists QBD76 at 18,000 taps, Hugo 1 at 26,000 and Dave at 164,000, saying each increase improved timbre, bass pitch and left-right soundstage. c w 15:36
• 2018-07-21Watts says Dave's filter took nine months and was only modestly better than Hugo's; half a million taps on the new FPGA sounded hugely, unexpectedly better than Dave. c w 21:02
• 2018-10-28Watts explains how TT2's volume display shifts with gain mode and where it clips, and gives delays of 34 ms for Hugo 1 and 63 ms for TT2 with video. Head-Fi, Oct 2018
• 2018-12-12Watts begins the story of how he arrived at a number for small-signal accuracy while developing DAVE, starting with designing Hugo One, the product that put Chord on the map. Pursuit Perfect System 19:47
• 2018-12-12Watts says six years of code from a scrapped reference DAC went into Hugo One, but adding crossfeed at 98% FPGA capacity forced gate-count cuts without losing performance. Pursuit Perfect System 20:32
• 2018-12-12Watts says both noise shapers were 200 dB yet differed; he finished Hugo with crossfeed at 98% capacity, then on DAVE's ten times larger FPGA investigated why depth differed. Pursuit Perfect System 22:58
• 2018-12-12Watts says Hugo One users claimed it could not drive some headphones, but usually they disliked a hard-sounding headphone and used a warm amplifier; he wanted to remove that issue. Pursuit Perfect System 36:40
• 2018-12-13Watts gives tap lengths of DAC64 (1,000), QBD76 (18,000), Hugo in 2013 (26,000) and DAVE (164,000), saying each increase improved bass definition and soundstage. Pursuit Perfect System 9:06
• 2018-12-13Watts says listening tests with Hugo, Hugo 2 and DAVE found no difference between USB cables, and the M scaler should be even less sensitive. Head-Fi, Dec 2018
• 2018-12-28Watts says white is dual data mode, two mono signals at 352/384; Hugo 1 cannot accept it and treats one mono signal as stereo, so use single BNC instead. Head-Fi, Dec 2018
• 2019-04-05Watts lists milestones in reducing the dominance effect: pulse array (1995), WTA with DAC64 (1999), Hugo (2014) and the M scaler (2016). Head-Fi, Apr 2019
• 2019-05-25Watts explains decimation and aliasing, says tiny aliasing is audible, and preferred Hugo 2's -220 dB DSD filter to Hugo 1's -130 dB and DAVE's DSD+. Head-Fi, May 2019
• 2019-06-01Watts says crossfeed improves depth on Dave, Hugo 2 and TT2, not Hugo, due to 350dB noise shaping; Dave took 2 to 3 years and later DACs reuse its code. Head-Fi, Jun 2019
• 2019-09-20Watts says Qutest uses Mojo's Class A stage for easy loads, while Hugo 2's noise shaper output is crossover-distortion free into 33 ohms, with 120 dB feedback at 20 kHz. Head-Fi, Sep 2019
• 2019-11-18Watts says Hugo 2 gives 1050 mW into 8 ohms against about 750mW for the original, and stays more linear into 33 ohms, sounding smoother and warmer. Head-Fi, Nov 2019
• 2019-12-16Watts recounts that adding crossfeed to the Hugo One prototype, at 95 percent FPGA use, forced a simpler 200 dB noise shaper, which he expected to sound worse. Passion for Sound 12:06
• 2019-12-16Watts says the simpler Hugo noise shaper sounded better in depth and detail; DAVE's ten-times-larger FPGA let him test this, and a 220 dB noise shaper improved depth. Passion for Sound 12:52
• 2020-01-02Watts says RF causes noise floor modulation; adding RF filters to Hugo 2's USB made it sound like optical, unlike Hugo, with no measurable change, so unmeasurable modulation matters. Passion for Sound 12:11
• 2020-05-04Watts says the JitterBug helped Hugo 1, suspects USB treatments add brightening RF, heard no USB-optical difference on M scaler or ungrounded Hugo 2, and enjoys Tangerine Dream box sets. Head-Fi, May 2020
• 2020-06-25Watts says his Chord work was a non-commercial side activity until Hugo, when Chord's business took off and he spent more time on high-end design. Part-Time Audiophile 4:40
• 2020-06-25Watts says portable designs have a power budget, 2.5 watts for Hugo and 1.7 watts for Mojo, and he shaved milliwatts on Hugo 2 to spend on performance. Part-Time Audiophile 29:37
• 2020-06-25Watts says 192 versus 48 kHz is subtle but 768 kHz is a massive change, and Hugo One's filtering to 104 MHz made piano notes' starts and stops audible. Part-Time Audiophile 41:12
• 2020-09-30Watts says his DACs use switching regulators, which sounded better than linear ones from Hugo onward, and that random RF noise, not fixed switching noise, causes noise floor modulation. Head-Fi, Sep 2020
• 2020-12-04Watts used crossfeed on Hugo only for hard-panned 60s recordings but runs it at max on Hugo 2 for depth; shrinking dimensions by a third would more than double temperature. Head-Fi, Dec 2020
• 2020-12-30Watts says Mojo lacked crossfeed because of button count, power dissipation and his lesser enthusiasm then; Hugo 2's transparency and depth made crossfeed essential for him. Head-Fi, Dec 2020
• 2021-10-25Watts says the gap to live sound remains large, his current path began with Hugo 1, which revealed ear/brain sensitivity, and progress depends on large FPGAs. Head-Fi, Oct 2021
• 2022-01-31Watts agrees, noting the original Hugos and Mojos did the same, and says the 3.5 mm connector's advantage is that it is very small. Darko.Audio 3:34
• 2022-01-31Watts says formula, coefficients and four settings match DAVE, Hugo 2 and Hugo one; only implementation differs, using biquads instead of Hugo 2's dedicated serial DSP core. Darko.Audio 48:10
• 2022-02-12Watts says SMPS tones do not cause NFM unlike random RF, recalls switching regulators beating linear in Hugo, and prefers power banks for isolation from RF ground currents. Head-Fi, Feb 2022
• 2022-03-19Watts says crossfeed on Hugo 1 gave no out-of-head sense, but on Hugo 2 it improved depth, and Mojo 2 is similar thanks to better small signal accuracy. MFG Audio Reviews 41:42
• 2022-06-12Watts recounts crossfeed giving an out-of-head experience with a Hugo 2 prototype on a flight, never with the original Hugo, linking better small-signal accuracy to more effective crossfeed. Head-Fi, Jun 2022
• 2022-10-26Watts advises turning Hugo 2 off when unused, especially for 12 hours or more, notes its batteries are reliable, and says 10-year-old Hugo 1 batteries worked fine. Head-Fi, Oct 2022
• 2023-02-04Watts says until 2015 his improvements made the best recordings better and the worst worse, then Hugo brought a dramatic change because FPGAs let him create his own digital circuit. Dusty Audio 15:25
• 2023-02-04Watts says older FPGAs limited his filters and noise shapers; 2015 FPGAs had three or four times the capacity, and in Hugo poor recordings improved more than good ones. Dusty Audio 16:13
• 2023-02-04Watts says after Hugo he enjoyed piano music, hearing timbre, attack and flow, and could appreciate 1930s mono recordings despite their distortion and noise. Dusty Audio 17:08
• 2023-02-04Watts says improving small-signal amplitude accuracy improved depth, and developing Dave with a bigger FPGA after Hugo let him try better noise shapers. Dusty Audio 20:50
• 2023-02-04Watts says noise shaper performance is measured by digital simulation; for Hugo he worked to 200 dB (32-bit accuracy), while chip makers generally work to 140 dB. Dusty Audio 21:41
• 2023-02-05Watts says Hugo must keep power low: linearly regulating 8 volts to a 1 volt, one amp FPGA core dissipates 8 watts; a Mojo-style unit manages 3 watts at most. Soundnews 25:32
• 2023-02-05Watts says Hugo can dissipate about 4 watts without fans; a 95% efficient switch-mode regulator from 8 volts to 1 volt cuts dissipation to about one and a half watts. Soundnews 26:15
• 2023-02-11Watts says improvements are easiest to hear on poor recordings, first noticed with Hugo, and pre-1968 master tapes lose their realism through ADCs and conventional DACs' transient timing errors. Head-Fi, Feb 2023
• 2023-03-30Watts gives Stealth SPL at 0dBFS (98.3 dB Hugo/Mojo, 100.0 Dave, 103.4 TT2 headphone, 109.1 balanced), warns against long listening above 80dB, and suggests volume settings. Head-Fi, Mar 2023
• 2023-10-01Watts says that as he improved products such as Hugo, Mojo 2, Hugo 2 and DAVE, headphones started to sound different. The Source AV 21:37
• 2024-01-07Watts says the 10-minute warm-up he heard on flights was most likely his ears adjusting to cabin pressure or the headphones, not the DACs, and that Mojo 2 exposes headphones with poor LF distortion. Head-Fi, Jan 2024
• 2024-03-20Watts says he used linear regulators on the DAC64 expecting switchers to sound worse, but Hugo One needed internal switch mode supplies for efficiency, so he compared the two. MFG Audio Reviews 27:50
• 2025-01-13Watts compares feed-forward correction (about 20dB) with his second-order analog noise shaper (90dB), showing TT2 into 8 ohms, and links crossover distortion to amplitude-dependent transient delay. Head-Fi, Jan 2025
• 2025-05-12Watts lists tap counts: DAC64 1,000 (1999), QBD 18 thousand, Hugo 26 thousand (2013), DAVE 164 thousand, Hugo M Scaler 1 million; more taps and WTA improvements each improved sound. Audiophile Junkie 13:35
• 2026-10-02Watts says everything changed with Hugo, the first Hugo, in 2014. HiFi Buys 25:30
• 2026-10-02Watts says in 2014 he had an FPGA about 10 times larger than before. HiFi Buys 25:39
• 2026-10-02Watts says Head-Fi gave Chord instant reaction: when Hugo came out people raved within days and sales rose, and headphones have improved markedly. HiFi Buys 2:25:23

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