Hugo M Scaler: everything he said

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

2017-12-26Watts says his WTA filters roll off very fast: 49,152 taps reach -1dB within 75Hz of FS/2, the M Scaler's 1M taps within 4Hz, matching ideal sinc beyond 16-bit accuracy. Audiophile Style, Dec 2017
2018-02-11Watts says a standard stereo 3.5mm cable connects Hugo 2 to an M scaler; cheap non-75-ohm cables worked at 705/768 kHz because of de-glitching and rise/fall adjustment. Head-Fi, Feb 2018
2018-02-17Watts calculates that, at 10 seconds per entry on a Casio, a human would take 33,769 years to compute one second of music for the M scaler. Head-Fi, Feb 2018
2018-02-22Watts says Chord announced at the Blu 2 launch that other M scaler units would come, but says no more; Qutest uses a 4-layer PCB of Hugo 2's spec. Head-Fi, Feb 2018
2018-02-23Watts says a separate, galvanically isolated M Scaler keeps that noise out of Dave, isolation took two prototypes, another M Scaler is in progress, and timing recovery reaches 16-bit accuracy. MajorHiFi 20:49
2018-03-06Watts says Hugo 2/Qutest use 67.5mS of data versus 1mS for conventional filters, minimum phase sounds soft, the M scaler uses 1.37 seconds, and more M scalers will follow. Head-Fi, Mar 2018
2018-03-16Watts attributes reduced loudest-instrument dominance to no noise floor modulation and the WTA filter, says an M scaler enhances it, and calls dominance a major cause of fatigue. Head-Fi, Mar 2018
2018-03-17Watts says Davina will use Choral metalwork and all new DACs will accept M scaler dual data, which is why Qutest and Hugo 2 have that input. Head-Fi, Mar 2018
2018-03-20Watts says complex USB gear adds RF brightness, optical is the benchmark, and gives WTA overload margin, M scaler latency (630 ms, video mode 104 mS) and 16.6-bit accuracy. Head-Fi, Mar 2018
2018-03-22Watts explains the 2.75dB WTA overload margin, delays audio in JRiver to keep 1M taps with video, describes visible noise floor modulation, and gives DAVE and Hugo 2 level limits. Head-Fi, Mar 2018
2018-04-27Watts responds to a review calling Hugo 2 merciless, contrasts live drums with reproduction, states Davina's goals of depth and speed, and says all design is his. Head-Fi, Apr 2018
2018-05-07Watts says Hugo 2's DSD filter exceeds 200 dB at 88.2 kHz, used on Blu 2; he heard only brain break-in; the M scaler outputs 705.6 kHz PCM from DSD. 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
2018-06-27Watts says MQA's degradations become obvious with WTA and M scaler; converting the 56-bit WTA output to 24 bits, triangular dither sounded worse than his truncation noise shapers. Head-Fi, Jun 2018
2018-07-01Watts says AAC, short filters, MQA, minimum phase, NOS and DSD sound soft and warm from transient timing uncertainty; turning off the incisive filter similarly sounds warmer. Head-Fi, Jul 2018
2018-07-19Watts says modern ADCs' -6dB at FS/2 causes unrepairable aliasing, yet all recordings benefit from an M scaler; Davina will decimate without aliasing, and he will release randomly named files. Head-Fi, Jul 2018
2018-07-19Watts says it will identify losses from ideal 768 decimation then M scaling back up; the M scaler exceeds 16-bit recovery, but whether that suffices is open. needs context Head-Fi, Jul 2018
2018-07-21Watts opens his talk on why the M Scaler has a million taps, saying timing is an essential perceptual cue for the brain, with transients central to it. c w 4:25
2018-07-21Watts says a million taps was impossible in 1981, so he favored vinyl then; WTA listening tests followed, and the Xilinx A200T now gives 740 DSP cores at 12 watts. c w 17:48
2018-07-21Watts says a million taps now run at the same power as DAC64's thousand in 1999, and at a million taps the WTA coefficients become identical to a sinc function. c w 18:36
2018-07-21Watts says the coefficients match sinc to the 16-bit level, guaranteeing reconstruction of the bandlimited signal to 16-bit accuracy for CD, then begins describing FIR problems on Dave. c w 19:24
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
2018-07-21Watts says the transformational change and good timing closure led him to the full million taps, a goal dating 'back in 1991' (as spoken), requiring a new memory-efficient filter architecture. c w 21:47
2018-07-21Watts says the M Scaler filter is half a million lines of hand-written code, using a new architecture where one memory block feeds eight DSPs running as individual threads. c w 22:34
2018-07-21Watts says the M Scaler's million-tap WTA core is identical to Blu's, lists isolated USB, BNC and optical inputs and dual BNC, BNC and optical outputs, adjustable rate and pass-through. c w 23:19
2018-07-21Watts says gain is unchanged for listening tests; the filter's 1.3 seconds of music means 0.63 s delay, so video mode uses an asymmetric filter with 100 ms delay. c w 24:08
2018-07-21Watts describes auto video mode on 48 kHz input, automatic source switching when USB is silent, remote control, and a DX mode for DX power amplifiers still under development. c w 24:49
2018-07-21Watts says the DX amps are pulse-array-topology DACs of 400 or 500 watts, with volume set by the M Scaler, which he runs from a battery bank on flights. c w 25:32
2018-07-21Watts says he uses mains in business class and carries the M Scaler because Hugo 2 and Dave are hard to hear without it; customs has not objected yet. c w 26:18
2018-07-21Watts sums up: high-end DACs use a few hundred taps, the M Scaler has 10,000 times more processing, recovering 16-bit CD to 16-bit accuracy and transient timing to unprecedented accuracy. c w 27:04
2018-07-21Watts says the M Scaler gives better bass definition, instrument separation and focus, and unexpectedly opens up the soundstage so reverb is heard from different walls. c w 27:48
2018-07-21Watts says past WTA changes never altered depth, and suspects the 1.3-second analysis span, similar to concert-hall RT60 times, explains it; he hopes Davina will show why. c w 28:33
2018-07-21Watts says the M Scaler recovers the original analog signal to better than 16-bit accuracy, then opens the floor to questions. c w 29:20
2018-07-21Watts says he uses the M Scaler with Hugo 2 on planes, Hugo 2 and Qutest work fine, and he regrets not giving Mojo 768 capability. c w 29:47
2018-07-21Watts says the M Scaler's code and performance are exactly the same as Blu 2's, and he has eliminated the need for ferrites. c w 30:23
2018-07-21Watts says improved isolation on the BNC output drivers removes the need for ferrites, which in listening tests made it sound slightly worse; the code is identical. c w 30:37
2018-07-21Watts says selecting 384 kHz halves the taps output; 768 kHz gives 1.3 uS resolution, while 1536 would halve the data window to 0.63 seconds; 768 is the listening-test optimum. Head-Fi, Jul 2018
2018-07-22Watts says Hugo 2 accepts the M Scaler's full 768kHz dual data via 3.5mm to RCA cables and BNC adaptors, and mentions 50 flight hours with the pair. Head-Fi, Jul 2018
2018-07-22Watts gives typical 12W draw, manual and auto video modes (1M taps 0.63 S delay, 2/3M taps 0.1S), and says Hugo 2 gets full 1M taps at 768k. Head-Fi, Jul 2018
2018-07-22Watts says it is absolutely fine with Dave, its benefit over Blu2 being no need for ferrites on the BNC cables, which were only the top layer of icing. Head-Fi, Jul 2018
2018-07-23Watts explains Hugo 2's dual data link (two 384k cables), says FPGA RF noise keeps the scaler separate, shows his homemade flight cable, and rates USB and optical equal. Head-Fi, Jul 2018
2018-07-24Watts says with Aeon headphones he would choose the M Scaler over TT2 as an upgrade from Hugo 2, calling it transformational, unless driving difficult headphones or speakers. Head-Fi, Jul 2018
2018-07-24Watts prefers automatic video mode for convenience; projectors and quality TVs delay enough that 100mS is fine with audio delay set to 0, since audio before video bothers the brain. Head-Fi, Jul 2018
2018-07-26Watts says Mojo can take the M Scaler's 384 kHz output but lacks dual coaxial inputs for the full 768 kHz. Head-Fi, Jul 2018
2018-07-26Watts says he has heard the change from 384 to 768 kHz on Hugo 2 and it is surprising. needs context Head-Fi, Jul 2018
2018-07-26Watts says the M scaler needs bit-perfect input because PC upsamplers lack the processing power and a sinc-like WTA algorithm; its SPDIF output is asynchronous but the DPLL is transparent. Head-Fi, Jul 2018
2018-07-26Watts posts his CanJam presentation: transients cue placement, pitch and timbre; conventional filters mistime them; 1M WTA taps match sinc to 16.6 bits using 528 DSP cores. Head-Fi, Jul 2018
2018-07-26Watts says the M scaler reconstructs to better than 16 bits; after the big change from 0.5M to 1M taps he cannot say whether more taps help; Davina will show. Head-Fi, Jul 2018
2018-07-26Watts reports no difference, says Blu 2 avoided problems he had with the Hugo M Scaler, and never needed USB isolation since the noise comes from the FPGA. needs context Head-Fi, Jul 2018
2018-07-26Watts says Qutest, Hugo 2, TT2 and Dave share the post-scaler process (WTA2 to 256FS, third-order filter to 104 MHz), notes diminishing returns, and previews DX amps' transparency. Head-Fi, Jul 2018
2018-07-26Watts says the M scaler uses 1.42 s of music at 44.1 kHz, giving 0.71 s delay (0.65 s at 48k), hence the low-latency filter option. Head-Fi, Jul 2018
2018-07-27Watts explains dual-data and DX modes, M scaler DSD-to-PCM conversion with Hugo 2's 220 dB filter, says algorithm beats tap length, and compares R2R and delta-sigma timing errors. Head-Fi, Jul 2018
2018-07-27Watts doubts vendors' software tap claims such as Audirvana's 500,000 taps, says PCs are noisy and poor at real time, and that filter structure alters sound. Head-Fi, Jul 2018
2018-07-29Watts hears no difference between battery and the supplied PSU, warns non-supplied PSUs may void warranty (never above 15V), and found laptop battery vs mains and optical vs USB identical. Head-Fi, Jul 2018
2018-07-29Watts says his Aeon Closed headphones suppress noise well, and the M scaler is worth the hassle on flights of 12 hours or even 90 minutes. Head-Fi, Jul 2018
2018-07-30Watts says he did not delay the project by six months to a year for a marginal feature, since the USB transmit code and device were untested. needs context Head-Fi, Jul 2018
2018-07-30Watts confirms a summary but notes optical has an upper limit of 192 kHz, which gives 0.25M taps. needs context Head-Fi, Jul 2018
2018-08-02Watts says Blu 2 and M scaler filter code is identical, explains that upscaling recovers transient timing rather than adding information, and why pulse array needs DSD converted to PCM. Head-Fi, Aug 2018
2018-08-04Watts says TT2 is warmer with better depth than Hugo 2 with the M Scaler too, and integer decimation from 192 to 96 loses little with a decent filter. Head-Fi, Aug 2018
2018-08-04Watts clarifies that the M Scaler was used in both cases when he found TT2 better than Hugo 2 in depth and resolution. needs context Head-Fi, Aug 2018
2018-08-04Watts says Mojo's 768 kHz works on USB only; going from 0.5M to 1M taps is a big change, so audition the M scaler with Mojo against a Hugo 2. Head-Fi, Aug 2018
2018-08-04Watts says the issue is non-linear transient timing, the master clock and source jitter are unimportant thanks to the DPLL, and Hugo 2 gets full 1M taps via 3.5mm-to-BNC adaptors. Head-Fi, Aug 2018
2018-08-05Watts says Mojo gains from 0.5M taps but upgrading Mojo may be better, and Mojo lacks an extra SPDIF decoder because power mattered and no M scaler existed then. Head-Fi, Aug 2018
2018-08-06Watts says the brain uses transient information for location, timbre and pitch, and recounts a listener saying the M Scaler made the tempo sound slower, which he relates to flow. Pursuit Perfect System 2:47
2018-08-06Watts says without the M Scaler musical flow sounds mechanical, jerky and disjointed, while with it you perceive the timing interplay between instruments that normal digital lacks. Pursuit Perfect System 3:35
2018-08-06Watts says the M Scaler is fundamentally 3 bits more accurate than the TT or DAVE, guaranteed to recover the original analog signal to better than 16 bits. Pursuit Perfect System 4:13
2018-08-06Watts says it is more complicated: instrument separation, timbre variation and sense of flow come only with the scaled option, while DAVE gives transparency, detail, resolution and depth. Pursuit Perfect System 4:43
2018-08-06Watts says the M Scaler uses the exact filter and the same FPGA as the Blu, pulled straight across, because the filter took too long to design to change. Pursuit Perfect System 5:42
2018-08-06Watts says the M Scaler makes a huge difference to video sound, with stunning Blu-ray depth; he uses JRiver's negative video delay to cover the 'six, three seconds' latency. Pursuit Perfect System 6:37
2018-08-06Watts found BNC cable differences for Hugo 2 vanished once the headphone cable did not touch them; length and exact 75 ohm do not matter thanks to de-glitch circuitry. Head-Fi, Aug 2018
2018-08-06Watts says video needs the video filter for lip sync, which uses 2/3 M taps but still outputs 705/768 kHz on the dual BNCs. Head-Fi, Aug 2018
2018-08-06Watts says Blu-ray films with a -0.63 s video delay in JRiver sound stupendous with the full 1M taps, with cavernous soundstage and separation. Head-Fi, Aug 2018
2018-08-07Watts says yes, by pressing the DX volume buttons together on the Hugo M Scaler, and TT2 has a DIM setting that dims everything. needs context Head-Fi, Aug 2018
2018-08-07Watts says he carries a TT2 and programming tool while Chord is still testing it, and will return to traveling with a Dave and Hugo M scaler. Head-Fi, Aug 2018
2018-08-09Watts gives Hugo M Scaler dimensions (40.5 mm tall, 235 mm wide, 236 mm deep), its PSU size (140x50x30 mm), and TT2's 51 mm height. Head-Fi, Aug 2018
2018-08-12Watts says the M scaler makes compression losses audible, audiophile BNC cables sound same or worse, TT2 measures identically in Class B, and the units stack. Head-Fi, Aug 2018
2018-08-13Watts advises 75 ohm BNC cables matching the M scaler's output; scaled DACs still differ: Dave beats Qutest, with a 20-element pulse array and 30 times lower distortion. Head-Fi, Aug 2018
2018-08-13Watts says the M scaler's Hugo 2 DSD filter beats Dave's DSD+, but DSD's amplitude-related timing errors and small-signal losses cannot be recovered; Davina should surpass PCM and DSD. Head-Fi, Aug 2018
2018-08-13Watts says he keeps it in PCM+ mode with an M scaler attached. needs context Head-Fi, Aug 2018
2018-08-13Watts says Blu Mk2 has the same DSD filter, and the Hugo M Scaler began as a copy of the Blu 2 project with only control code changed. Head-Fi, Aug 2018
2018-08-17Watts says the video filter uses the maximum delay without significant lip-sync issues, 104 ms, since TVs with frame interpolation need an audio delay; longer delay sounds better. Head-Fi, Aug 2018
2018-08-20Watts speculates why the test filter is poor, and says the 16FS, WTA2 256FS and 2048FS path is identical from Qutest to Dave; noise shaper, pulse array and analog differ. Head-Fi, Aug 2018
2018-08-21Watts lists his sources: a Motorola Android phone with Onkyo HF Player, JRiver on Windows 10, a Kimilar OTG adaptor for the M scaler, and generic certified USB cables. Head-Fi, Aug 2018
2018-08-27Watts says the M scaler draws 13W, asks posters to keep Head-Fi life-affirming, and says MQA's first unfold belongs in the player but the original 44.1k is better. Head-Fi, Aug 2018
2018-08-31Watts says the original is the unsampled analog signal; the M scaler's million taps match ideal sinc to better than 16 bits, recovering transient timing regular filters get wrong. Head-Fi, Aug 2018
2018-09-01Watts explains that 16-bit accuracy refers to the ideal sinc, errors arise only with transients, NOS is crude sample-and-hold, and delta-sigma ADCs suffer half-band decimation aliasing. Head-Fi, Sep 2018
2018-09-02Watts says the M scaler matches a perfect sinc to 99.98%, the worst case for any signal; a 1kHz sine would be 99.9999996% accurate, transients giving larger errors. Head-Fi, Sep 2018
2018-09-05Watts explains the Hugo M scaler OP SR colors (red pass through, green 176.4/192, blue 352.8/384, white 705.6/768 1M taps); only white enables dual data mode. Head-Fi, Sep 2018
2018-09-09Watts says the HF filter and WTA2 settings are unaffected by the M scaler, which works from 1FS to 16FS, and explains the vague autumn delivery as distribution time. Head-Fi, Sep 2018
2018-09-14Watts says linear PSUs lack RF filtering and sound brighter, Qutest benefits hugely from the M scaler but an M-scaled Dave easily beats an M-scaled Qutest. Head-Fi, Sep 2018
2018-09-14Watts advises the green filter: with 192k recordings the M scaler passes ADC noise up to 96 kHz, and the HF filter smooths sound by lowering noise floor modulation. Head-Fi, Sep 2018
2018-09-18Watts says the M scaler PSU came from TT2 testing, grounded C13 PSUs caused ground loops, quality SMPS beat linears, the Chord driver works, and auto low-power mode exists. Head-Fi, Sep 2018
2018-09-20Watts says the first M scaler was built 15 months earlier across four hardware versions, and he heard no hardware break-in, only brain break-in. Head-Fi, Sep 2018
2018-09-21Watts says something needs the Davina project, which he is working on, and pass-through mode has the same 2.75 dB loss, making AB testing easy. Head-Fi, Sep 2018
2018-09-22Watts says dual BNC operation applies only at full 1M taps at 705/768 kHz; otherwise it runs single-data mode at up to 352/384 kHz. Head-Fi, Sep 2018
2018-09-23Watts says the behavior is correct, dual BNC operation works only on white, and he will get the manual corrected. Head-Fi, Sep 2018
2018-09-24Watts says a connector is a standard 5.5 x 2.5 mm, he now takes the M scaler even on short flights, and describes connecting to performances, especially pre-1968 recordings. Head-Fi, Sep 2018
2018-09-26Watts says he designed IIR and FIR Davina decimation filters with over 250 dB rejection to test bandlimiting; he expects pre-ringing at 22.05 kHz to prove a red herring. Head-Fi, Sep 2018
2018-09-27Watts advises buying the original master, especially 96k, since SRC to 44.1 harms sound, but says 44.1 M scaled to 705k beats an unscaled 96k source. Head-Fi, Sep 2018
2018-10-01Watts says a DPLL removes optical input jitter, output uses a low-jitter analog PLL, the M scaler auto powers down, and Blu 2 standby affects only the CD mech. Head-Fi, Oct 2018
2018-10-13Watts names the Poweradd Pilot Pro 2, which powers the M Scaler at 12 V and Qutest from USB; at 85 Wh it passes airports, giving 35 hours on Qutest. Head-Fi, Oct 2018
2018-10-18Watts says supercaps isolate audio frequencies but do nothing for RF and leakage, so the M scaler, not being analog, has none; he also mentions heavy workload. Head-Fi, Oct 2018
2018-10-18Watts has had no issues with cheap 1.5m or bodged screened cables on Hugo 2, suggests adaptors with supplied BNC cables, and says the M scaler auto enters low-power mode. Head-Fi, Oct 2018
2018-10-23Watts explains the M scaler matches sinc to 16.7 bits, fixing transient timing, but cannot repair aliasing from modern half-band ADCs, possibly why 1960s recordings sound amazing. Head-Fi, Oct 2018
2018-10-24Watts says many audiophile cables are not true 75 ohm RF cables, so Chord supplies RF cables used in testing, and 768 kHz over SPDIF is technically very challenging. Head-Fi, Oct 2018
2018-10-25Watts says native DSD works on the M scaler (Roon, JRiver) using Dave code if SR OP is white, else it is silent; dual data needs 50 Mbit/s per cable. Head-Fi, Oct 2018
2018-10-27Watts says the M Scaler's musical benefits matter most, whether it is transformational depends on the listener and system, and buyers should listen first with time. Head-Fi, Oct 2018
2018-10-27Watts says the Hugo M Scaler is not sensitive to RFI, and that Dave is more transparent while M Scaler with TT2 is better for timbre, flow and separation. Head-Fi, Oct 2018
2018-10-30Watts says a black M scaler light means the source sends digital silence, calls a headphone amp after TT2 insane, and says the new DSD filter has aliasing below -250 dB. Head-Fi, Oct 2018
2018-11-01Watts says 320k MP3/AAC softness is more apparent via TT2 and M Scaler, single-driver speakers are transparent but flawed, and 7W SE suffices for his 803 D3. Head-Fi, Nov 2018
2018-11-01Watts says clip-on ferrites do not work with the Hugo M Scaler, sounding slightly brighter and flatter, probably because the gap interferes with its built-in filtering. Head-Fi, Nov 2018
2018-11-01Watts says yes, he often uses it that way on very long flights, powering or charging Hugo 2 and the M scaler together. needs context Head-Fi, Nov 2018
2018-11-02Watts says it matches Blu 2 with 3 dB headroom, pass-through is volume matched, the main change is musical and takes time, and the supplied SMPSU is fine. Head-Fi, Nov 2018
2018-11-05Watts says red OP SR is volume-equalized pass-through, headphones won't need a DX amp, units may stay on (M Scaler auto-shutdown, TT2 standby), and announces a Hong Kong event. Head-Fi, Nov 2018
2018-11-05Watts says the OP SR light always stays on, even in auto shutdown. Head-Fi, Nov 2018
2018-11-06Watts says servers bring no sound-quality gain, their perceived transparency being RF noise raising noise floor modulation and brightness, while the M scaler transforms musical performance. Head-Fi, Nov 2018
2018-11-07Watts says PCM can in theory recover the bandlimited signal perfectly given enough processing, hence the M scaler, while DSD is format limited and falls in a lower league. Head-Fi, Nov 2018
2018-11-11Watts explains the M scaler's apparently slower tempo as reduced dominance effect, because 1M-tap WTA cuts program-dependent transient timing errors; 164,000 to 1M taps is very audible. Head-Fi, Nov 2018
2018-11-14Watts says he has never used Krell, and that M Scaler pass-through follows the input rate, so 44.1 kHz playback turns Hugo 2's indicator red. Head-Fi, Nov 2018
2018-11-16Watts says he uses only the Hugo M Scaler and Hugo 2 on planes, and packs a TT2 to use with the M scaler in hotel rooms. Head-Fi, Nov 2018
2018-11-18Watts says TT2 needs no balance control with digital volume, a 705/768 indication means the M Scaler works, and suggests a week of listening before comparing pass-through. Head-Fi, Nov 2018
2018-11-18Watts lists three causes of DAVE dropouts with the M scaler: the source, DAVE's dual-data detector, and SPDIF losing lock; try BNC 3 and 4, else service. Head-Fi, Nov 2018
2018-11-20Watts says 2 m standard 75 ohm cables sound a bit better than 1 m, but he has no evidence shorter cables reduce dropouts. Head-Fi, Nov 2018
2018-11-22Watts says the M scaler PSU is deliberately ungrounded to avoid earth loops, grounded PSUs sound brighter, overvoltage failures void warranty, and 15 V is the maximum input. Head-Fi, Nov 2018
2018-11-22Watts suggests setting DAVE to PCM+ mode with the M scaler. needs context Head-Fi, Nov 2018
2018-11-28Watts says a random timing error would need 24 bits beyond 1M taps, but it is program-correlated so matters more than dither; video mode uses an asymmetric filter. Head-Fi, Nov 2018
2018-11-30Watts says the dual BNC outputs are isolated from the other outputs, so noise from other DACs should not upset DAVE, and the optical output is fully isolated. Head-Fi, Nov 2018
2018-12-06Watts says toggling pass-through on a flight with Hugo 2 and Aeons was a huge difference, smaller only with non-transparent transducers, and stress kills AB test sensitivity. Head-Fi, Dec 2018
2018-12-06Watts says TT2 is more transparent and refined than Hugo 2, the refinement being more apparent, so pass-through differences may be more noticeable with TT2. Head-Fi, Dec 2018
2018-12-07Watts says the 4x (48 to 192 kHz) filter uses exactly a quarter of the 16x coefficients, not a decimation, and is volume adjusted with near-Gaussian 24-bit dither. Head-Fi, Dec 2018
2018-12-07Watts says MC 21, 22 and 24 on USB never gave him issues, lower output rates are not down conversions, and pass-through is not bit perfect due to attenuation compensation. Head-Fi, Dec 2018
2018-12-07Watts says in pass-through the WTA filter becomes a one-tap filter, while the SRAM stays identical so group delay is unchanged. Head-Fi, Dec 2018
2018-12-09Watts says vinyl sounds soft and distorted to him; M scaler with DAVE beats vinyl on his objective criteria and emotional involvement, citing Pink Floyd Relics and Yes albums. Head-Fi, Dec 2018
2018-12-09Watts says he rarely has airport security problems with DAVE, the M scaler or Mojo, carried on or checked, recounting questions in Indonesia and over Hugo 2 in Hanoi. Head-Fi, Dec 2018
2018-12-12Watts says it works with the M Scaler, calls the measurements state of the art (only DAVE beats them), and gives the jitter-test floor as minus 170 dB, not 178. Pursuit Perfect System 40:30
2018-12-13Watts says the sinc function falls below 16 bits at about three quarters of a million taps, so the 1 million tap M Scaler reaches 16.7 bits. Pursuit Perfect System 13:16
2018-12-13Watts lists Hugo M Scaler features (pass-through, video and auto modes, remote, DX), says it runs from 9 to 15 volts, and that he uses it with a battery on flights. Pursuit Perfect System 14:11
2018-12-13Watts says he carries his M Scaler on 10 to 13 hour flights and chose the 15 volt input so a standard laptop battery backup could power it. Pursuit Perfect System 15:04
2018-12-13Watts says the M Scaler gives a sense of being at the performance, 1960s recordings changing most, and improves pitch, melody, timbre, space and loud-instrument impact. Pursuit Perfect System 15:46
2018-12-13Watts attributes the M Scaler's stronger instrument power without cross-modulation to removing the timing modulation that past and future signal causes in conventional filters, restoring 16-bit accuracy. Pursuit Perfect System 16:26
2018-12-13Watts says his goal is emotional connection and musicality, which the M Scaler delivers for him, after a 35-year journey from impossible to achievable. Pursuit Perfect System 17:13
2018-12-13Watts says his music buying grew with the Hugo and more with the M Scaler, which is why he carries one on flights, then opens questions. Pursuit Perfect System 17:56
2018-12-13Watts describes his flight rig: M Scaler, a Hugo, phone source and MrSpeakers headphones; in economy a battery runs it two hours, reaching about 45 degrees C. Pursuit Perfect System 18:35
2018-12-13Watts recounts lending his M Scaler for a show and then watching video on headphones without it, starting to describe his reaction. Pursuit Perfect System 19:29
2018-12-13Watts says longer taps improved bass, timbre and left-right staging but never depth, which he ties to small-signal accuracy, yet at half a million taps the soundstage opened up. Pursuit Perfect System 19:49
2018-12-13Watts says he cannot explain why going from DAVE's 164,000 taps to the M Scaler's 1 million opens the soundstage, suggesting its 1.3 second window matches concert-hall reverberation time. Pursuit Perfect System 20:30
2018-12-13Watts says listening without the M Scaler, for the first time in two years, sounded flat, and that the soundstage opening is what surprises people. Pursuit Perfect System 21:14
2018-12-13Watts says he listens to more electronic music lately; its artificial depth still opens up, and its abrupt stops let the M Scaler show starting and stopping of notes clearly. Pursuit Perfect System 22:17
2018-12-13Watts says amplified concerts blur left-right imaging and are poor for judging transparency, but convey immediacy, speed, separation and instrument power, which the M Scaler helps improve. Pursuit Perfect System 23:48
2018-12-13Watts explains 2 GHz ground-plane noise crossing the BNC isolation's 5pF; clip-on ferrites help Blu 2 but degrade the Hugo M Scaler, solid-core help slightly, cables beyond 2m don't. Head-Fi, Dec 2018
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
2018-12-15Watts says TT2's 98,304 taps switch off with an M Scaler, and TT2 was not engineered to sound warm but expected warmer than DAVE and more refined than Hugo 2. Head-Fi, Dec 2018
2018-12-16Watts says TT2 keeps DAVE's -3 dB equals 3 V RMS convention, clipping at +7 dB; CD cannot clip at +6 dB, with M scaler +10 dB, Blu-ray +13 dB. Head-Fi, Dec 2018
2018-12-16Watts says he has never seen an M scaler EMC issue, finds it odd since red is low power, and suggests repositioning, earthing via a BNC input, and moving cables. Head-Fi, Dec 2018
2018-12-16Watts says delay is 0.71 s at 44.1k and 0.65 s at 48k, while video mode's asymmetric filter cuts the future part to 0.104 s for lip sync. Head-Fi, Dec 2018
2018-12-17Watts says 2 V is 3.5 dB and 1 V 9.5 dB below 3 V; non-WTA upsamplers cannot predict the M Scaler, as longer conventional filters add near-zero coefficients. Head-Fi, Dec 2018
2018-12-19Watts says the poster needs to earth Qutest, really the power amps, since Qutest and the M scaler are both isolated from ground. Head-Fi, Dec 2018
2018-12-23Watts clarifies he called live amplified music awful, not genres; he loves prog rock, electronica and classical, says the M Scaler enhances depth, and asks for tolerance. Head-Fi, Dec 2018
2018-12-27Watts says the M scaler unexpectedly improves reverb and depth perception, normally tied to small-signal accuracy, speculating about its 1.438 s of data versus concert-hall RT60, unconvinced. 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
2018-12-29Watts says Chord confirmed the BNC connector datasheet states 75 ohms, size differences come from dielectric constant, and 75 ohm cable is essential since M Scaler outputs are 75 ohms. Head-Fi, Dec 2018
2019-01-08Watts says the M Scaler's FPGA die runs only a few degrees above the chassis, about 45 C when stacked, far below its 125 C rating, so reliability is unaffected. Head-Fi, Jan 2019
2019-01-09Watts gives TT2 distortion figures, 0.042 ohm output impedance and low-gain voltages, notes no distortion above 3 kHz at 12 W, and says the FPGA sits die-down on the chassis. Head-Fi, Jan 2019
2019-01-09Watts confirms 768 kHz is reaching Hugo 2, since dual data is lit, the M scaler shows 48k, and Hugo 2 shows the right color. Head-Fi, Jan 2019
2019-01-15Watts says no, because pass-through does not change the sample rate. needs context Head-Fi, Jan 2019
2019-01-23Watts says the M scaler does not affect filter choice as it only replaces WTA1; he uses green and only listens with M scalers, even on flights. Head-Fi, Jan 2019
2019-01-24Watts says the M scaler preserves ADC noise on hi-res recordings, so the HF filter still helps, and WTA2 is even more attractive with the M scaler. Head-Fi, Jan 2019
2019-01-27Watts says the M scaler makes CD equivalent to a 705 kHz recording to 16 bits; with native 705 input both it and DAVE's 164,000-tap WTA1 pass through. Head-Fi, Jan 2019
2019-02-04Watts says TT2 driving headphones draws about the same power as the M Scaler, giving about 6 to 7 hours from a Poweradd Pilot Pro 2. Head-Fi, Feb 2019
2019-02-09Watts prefers the M scaler's DSD filter, which decimates to 16FS with better than -220 dB above 88.2 kHz, to DAVE's DSD+, concluding aliasing causes decimation's sound problems. Head-Fi, Feb 2019
2019-02-09Watts says a cyan input light shows M Scaler dual data and 1M taps; optical matching USB proves his DPLL removes source jitter, and simpler, lower-power sources sound better. Head-Fi, Feb 2019
2019-02-15Watts says the HF filter is unaffected since it runs at 2048FS, and the M scaler passes ADC HF noise from 96k and 192k recordings like Hugo 2's WTA1. Head-Fi, Feb 2019
2019-02-22Watts says TT2 and M Scaler USB inputs are galvanically isolated, drawing about 250 mW from the source, which may drain a phone about 15% faster. Head-Fi, Feb 2019
2019-02-25Watts says battery power is the reference, optical and USB sound nearly identical on the M scaler, TT2 gains nothing from batteries, and 10 minutes of warm-up is needed. Head-Fi, Feb 2019
2019-02-26Watts says TT2 is built like mobile products, his has flown 250,000+ km in luggage, and he carries the M Scaler as carry-on without security issues. Head-Fi, Feb 2019
2019-02-26Watts gives DAVE's BNC channel mapping for the M scaler, says the DX output is for future products, and warns 705 to 768 kHz conversion adds distortion and noise. Head-Fi, Feb 2019
2019-03-03Watts says the Hugo M Scaler adds no dither at full 1M taps, treats 16-bit as 24-bit, and a PC set to 16-bit mode truncates and re-dithers 24-bit sources. Head-Fi, Mar 2019
2019-03-04Watts explains white/green adds a WTA 16FS-to-256FS stage replacing an IIR filter, why sinc accuracy needs long taps, and says preferring orange suggests an overly bright system. Head-Fi, Mar 2019
2019-03-08Watts says the M scaler converts DSD to 705 kHz PCM, output only via dual BNC; in hindsight he could have passed DoP through, and TT2 solves this. Head-Fi, Mar 2019
2019-03-12Watts explains how a mains-powered USB reclocker creates intersecting ground loops that defeat Qutest's isolation, and weighs an M Scaler against removing an external amp, advising a dealer trial. Head-Fi, Mar 2019
2019-03-21Watts explains what an FIR tap is, says the M Scaler matches an ideal sinc to better than 16 bits needing 1M taps, and doubling WTA taps doubles accuracy. Head-Fi, Mar 2019
2019-03-25Watts says 768k works fine on the M scaler, and an M-scaled Red Book file sounds like a native 768k recording, unlike native 384k recordings. Head-Fi, Mar 2019
2019-03-25Watts comments on upsampling experiments: stopband beyond -150 dB matters little, output rate should suit tap length, his Davina decimation reaches 250 dB, and truncation needs aggressive noise shaping. Head-Fi, Mar 2019
2019-03-26Watts says the M scaler passes 768k through, 768k sounds special against 384k, and 352.8/384k recordings he has heard sound little better than 44.1. Head-Fi, Mar 2019
2019-03-26Watts disagrees that 24-bit files benefit less from M scaling than 16-bit, saying reconstruction makes bit depth theoretically irrelevant; 24-bit files just start out better. Head-Fi, Mar 2019
2019-03-27Watts says M scaled DAVE beats M scaled TT2 in every regard, a larger gap than he expected; the earlier comment compared M scaler plus TT2 with DAVE alone. Head-Fi, Mar 2019
2019-03-28Watts says he is not unhappy with TT2, drives his B&W 802s from it, and was surprised DAVE's lead was so large, from factors other than noise shaping. Head-Fi, Mar 2019
2019-03-28Watts says electronic design is his alone, cost limited TT2 with a higher than expected BOM, he hit the price-performance sweet spot, and demand exceeds Chord's expectations. Head-Fi, Mar 2019
2019-03-29Watts says TT2 filters are interpolation tweaks not EQ, argues NOS DACs are not truly bit perfect, explains transient timing errors, and warns IIR EQ and dithered volume are not transparent. Head-Fi, Mar 2019
2019-04-03Watts says his 768k recording resembles M scaled 44.1k, doubling the rate cuts the error area fourfold, and R2R or 2.8 MHz noise-shaped DACs limit accuracy above 768k. Head-Fi, Apr 2019
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
2019-04-08Watts says Toslink is the reference input since it injects no RF into the ground plane, his DPLL removes source jitter, and he heard no consistent USB-optical difference. Head-Fi, Apr 2019
2019-04-09Watts says ringing is inaudible because 22.05 kHz is inaudible and bandlimited signals carry no energy there, calling the industry's Dirac-impulse view a misunderstanding of sampling theory. Head-Fi, Apr 2019
2019-04-11Watts compares his FIR and IIR Davina decimation filters on a square wave, explains phase linearity, says both reach 250 dB rejection, and expects FIR to sound better. Head-Fi, Apr 2019
2019-04-17Watts says M scaler cables need 2GHz ferrites, and clip-on ferrites do not work on the Hugo M Scaler because 2GHz ferrites are built into its drivers. Head-Fi, Apr 2019
2019-04-17Watts heard no change from ferrites on USB, suggests trying 300 MHz types, says clip-ons surprisingly made the Hugo M Scaler brighter, and defends his honesty. Head-Fi, Apr 2019
2019-04-19Watts says Dave cannot clip below +3 dB on the volume control, or +6dB with the M scaler attached. Head-Fi, Apr 2019
2019-04-19Watts says chip ferrites in the coax ground corrupted data, but USB tolerates ground ferrites as differential signaling, which is why the M Scaler is isolated on the transmit side. Head-Fi, Apr 2019
2019-04-25Watts says the M scaler's 56-bit output is reduced to 24 bits by -301 dB noise shapers; triangular dither sounds worse, and non-integer SRC degrades sound. Head-Fi, Apr 2019
2019-05-02Watts gives the M scaler's 65 C thermal trip, says it recovers transient timing to 16-bit accuracy rather than adding information, and attributes optical's darker sound to RF, not jitter. Head-Fi, May 2019
2019-05-12Watts says the M scaler's size keeps its case from reaching 90 C, measures radiative and convective cooling at about 50% each, and finds nearly all CDs now musically enjoyable. Head-Fi, May 2019
2019-05-18Watts gives three reasons DSD must be converted to PCM, notes Chord knows of the Linux DSD512 issue, and says 44.1 via M scaler sounds better. Head-Fi, May 2019
2019-05-19Watts says DSD-to-PCM is not lossless; his Hugo 2, TT2 and M scaler filters exceed 200dB rejection with -301 dB truncation, against about 60 dB in chips. Head-Fi, May 2019
2019-05-21Watts says pass-through keeps the same delay with the filter disabled, the M scaler's impact varies by listener, and lasting musical enjoyment matters more than transparency gains. Head-Fi, May 2019
2019-06-13Watts says 96 kHz releases are better but not enormously; doubling sample rate only quarters the timing error, and M scaled CD beats 192k; Davina will test this. Head-Fi, Jun 2019
2019-06-14Watts says Davina hit hardware and decimation-filter problems, argues audible timing errors are non-linear ones, and cites WTA 2 tests as evidence of sensitivity below the 7-4 uS interaural limit. Head-Fi, Jun 2019
2019-06-16Watts shows by a zero-crossing example why higher rates improve transient timing, says 705/768 kHz is needed, and says hi-res ADC noise causes noise floor modulation the HF filter reduces. Head-Fi, Jun 2019
2019-06-28Watts says TT2 typically draws 13 W as a DAC and the Hugo M Scaler 12 W when working. Head-Fi, Jun 2019
2019-07-17Watts says a DX output is dual AES plus volume data, then argues listening judgements and measurements both need great care, saying only the APx555 measures noise floor modulation accurately. Head-Fi, Jul 2019
2019-07-22Watts says the M scaler converts 48k to 768k with 16-bit sinc accuracy, each doubling of rate quarters the transient error area, and WTA2 timing gains above 768k remain audible. Head-Fi, Jul 2019
2019-07-23Watts says WTA1 changes bass, pitch, timbre and separation while WTA2 affects only note starts and stops, names the RME ADI-2 Pro for test recordings, and describes IIR final stages. Head-Fi, Jul 2019
2019-07-25Watts says his DPLL uses only frequency once locked, so even 2 uS of source jitter has no effect, and external flip-flops remove FPGA jitter, verified with switching stopped. Head-Fi, Jul 2019
2019-07-28Watts shares flight setups, saying the Hugo M Scaler fits in a man bag and gets warm after two hours. Head-Fi, Jul 2019
2019-08-01Watts says better transients make tempo seem faster while less dominance effect makes it seem slower; an M Scaler on Qutest mostly reduces dominance, sounding more measured. Head-Fi, Aug 2019
2019-08-10Watts says that in pass-through only one BNC cable is active, so the owner must connect the right cable or select the appropriate coax input. Head-Fi, Aug 2019
2019-09-09Watts says M scaler accuracy depends on input, far beyond 24 bits on sine waves, at least 16.7 bits on transients; DAVE 2 is unplanned and DAVE took 2.5 years. Head-Fi, Sep 2019
2019-09-10Watts says doubling WTA taps adds one bit of sinc accuracy, and 88.2/96k input runs the same coefficients as an 8-times filter, keeping accuracy and processing unchanged. Head-Fi, Sep 2019
2019-09-14Watts explains the trade-off between output rate and sinc accuracy at fixed taps, says 16FS is optimal for 1M taps, and rejects offline 16FS conversion over file size and metadata. Head-Fi, Sep 2019
2019-10-16Watts says TT2 shuts down below about 11 V and errors above 15.5 V, the M Scaler accepts about 5 to 15.5 V, and linear PSUs degrade sound and void warranty. Head-Fi, Oct 2019
2019-10-16Watts says ground-plane currents cause noise floor modulation, battery Hugo 2 into headphones showed no optical-USB difference, and his M scaler's dual galvanic isolation makes source noise a non-issue. Head-Fi, Oct 2019
2019-10-18Watts says pass-through is not bit perfect; it carries the M scaler's 2.76 dB insertion loss, so DAVE direct must be turned down 3 dB for comparison. Head-Fi, Oct 2019
2019-10-22Watts says, traveling with Hugo 2 and M scaler instead of TT2, he can live without TT2 but not without the M scaler, which he calls essential. Head-Fi, Oct 2019
2019-10-23Watts says the M scaler enters low power mode, not off, after ten minutes of digital silence, shown by the lone OP SR LED; pressing both DX buttons dims it. Head-Fi, Oct 2019
2019-11-06Watts says the M scaler outputs 2.5v pp terminated, and that a Hugo 2 with integrated M scaler on one FPGA is many years, possibly decades, away. Head-Fi, Nov 2019
2019-11-12Watts says 16 V from a PowerAdd could destroy the protection diode, 15 V is fine, and higher voltage is not better since everything becomes 5 V internally. Head-Fi, Nov 2019
2019-11-17Watts remarks it took him 30 years to create the M scaler and says more positive news on the pulse array ADC should come next year. Head-Fi, Nov 2019
2019-11-17Watts says linear PSUs will sound worse than the supplied PSU on mains, batteries give complete isolation, and the handbook's toroidal note is generic, not an M scaler problem. Head-Fi, Nov 2019
2019-11-25Watts says few DAC designers understand sampling theory or noise floor modulation, warns clip-on ferrites worsen the isolated M scaler, and says floating point creates noise floor modulation. Head-Fi, Nov 2019
2019-11-27Watts says Roon DSP EQ will not upset M Scaler transient reconstruction, but EQ is never fully transparent, risking loss of depth and detail. Head-Fi, Nov 2019
2019-11-27Watts explains 2 GHz loop currents through the DAC ground plane, why clip-on ferrites stopped helping after his M scaler treatments, and why linear PSUs degrade sound. Head-Fi, Nov 2019
2019-11-28Watts says a longer-tap scaler will not replace the Hugo M Scaler until much better FPGAs exist, with no sign from Xilinx, and expects pulse array ADC progress next year. Head-Fi, Nov 2019
2019-12-14Watts tells a TT2 owner every DAC upsamples, the M scaler matches sinc to 16 bits for accurate transients, blind tests are insensitive, and he uses Aeon Closed on planes. Head-Fi, Dec 2019
2019-12-18Watts says M scaler output is 11th-order noise-shaped to 24 bits at 768k for -301 dB accuracy, ranks Gaussian dither above TPDF, and advises keeping the source bit perfect. Head-Fi, Dec 2019
2019-12-19Watts says adding an M Scaler gives the full million taps, with coefficients identical to sinc to 16.7 bits, guaranteeing better than 16.7-bit reconstruction accuracy. Passion for Sound 19:56
2019-12-19Watts says required accuracy is found by making filters more sinc-like and listening; his first WTA filter, DAC64 in 1999, had 1,000 taps, the M Scaler one million. Passion for Sound 22:05
2019-12-24In a Christmas fun review, Watts says music sounds better on some aircraft, blaming cabin noise, pressure and humidity, ranks the A380, A350 and 787 best, and gives seating tips. Head-Fi, Dec 2019
2020-01-02Watts says if TT2 would only serve as a DAC into an integrated amplifier, you would be better off with the M Scaler, though transparency would be the same. Passion for Sound 23:23
2020-01-02Watts says TT2 is more transparent than Qutest (better noise shapers, components, supply, output stage), but the M Scaler uniquely brings timbre, pitch, separation and musicality. Passion for Sound 23:33
2020-01-02Watts says at similar prices he would choose TT2 plus M Scaler over a bare DAVE for musicality, though many will prefer DAVE for its extraordinary transparency. Passion for Sound 24:16
2020-01-02Watts says DAVE is much more transparent than even an M Scaler-fed TT2, the choice is personal, Qutest with another amplifier loses transparency, and many Qutest owners add M Scalers. Passion for Sound 24:58
2020-01-03Watts warns 18v or more destroys the Hugo M scaler's protection diode and voids that warranty, says a 9 or 12v power bank works fine, and notes Poweradd flight limits. Head-Fi, Jan 2020
2020-01-11Watts says USB only controls his APx555, advises staying at DSD64 rather than re-modulating to higher rates before M scaler and DAVE, and praises the M scaler's DSD filter. Head-Fi, Jan 2020
2020-01-20Watts explains isolating output-stage supply currents, shown in TT2's distortion plot, says delay follows tap length and oversampling, describes the M scaler's asymmetric video filter, and heard no USB-optical difference. Head-Fi, Jan 2020
2020-01-24Watts says M scaler/Dave can run at +9dB without clipping into loads above 16 ohms, and there is no news on the amps as he has been busy. Head-Fi, Jan 2020
2020-01-27Watts says dual-BNC 768k on Mojo was dropped in 2015 to save power and the manual corrected; Mojo takes 768k on USB, and the algorithm matters more than tap length. Head-Fi, Jan 2020
2020-02-25Watts says the M Scaler and TT2 detect sample rate differently, and advises padding track changes with silence in JRiver or a re-sync delay in Roon. Head-Fi, Feb 2020
2020-03-27Watts says the M scaler gives a natural sense of flow and less fatigue because loud instruments no longer modulate transient timing, about 10 times more accurate than DAVE alone. Head-Fi, Mar 2020
2020-04-01Watts says 55 kHz PSU noise is irrelevant to the M scaler; 2 pF isolation coupling at 2 GHz matters, the ungrounded supplied SMPS helps, and linear PSUs worsen it. Head-Fi, Apr 2020
2020-04-01Watts says he chose TT2's SMPS as the only one matching a battery's measured HF performance; being ungrounded raises 2 GHz loop impedance, slightly helping the M scaler too. Head-Fi, Apr 2020
2020-04-09Watts says mains conditioners neglect RF, a single-blind test tied a new HF filter's warmth to noise floor modulation, and DAVE is about 13-bit accurate, M scaler over 16. Head-Fi, Apr 2020
2020-04-09Watts says USB decoding and galvanic isolation work down to 3.3v VBUS, and the gain from better-than-16-bit over 13-bit timing varies by listener, but he needs the M scaler. Head-Fi, Apr 2020
2020-04-10Watts says Chord desktop DACs and the M scaler need 5v VBUS to power USB galvanic isolation, and portable DACs need VBUS on as a USB-connected flag. Head-Fi, Apr 2020
2020-04-11Watts says video mode is set to 104 mS, the longest delay usable with TV frame interpolation, and the delay stays fixed in pass-through in case video is playing. Head-Fi, Apr 2020
2020-04-11Watts says the M scaler preserves a recording's HF noise, being flat to FS/2 like an ideal sinc, so the DAC's HF filter, run from 16FS to 2048FS, removes it. Head-Fi, Apr 2020
2020-04-12Watts confirms a delay of 0.661 s with a 48k source with video mode off, in both pass-through and normal mode, halving at 96k and 0.165 s at 192k. Head-Fi, Apr 2020
2020-04-15Watts has not heard the M Scaler with the original Hugo TT, which would need one BNC as it is 384k max, and suggests trying TT2 with the M Scaler. Head-Fi, Apr 2020
2020-04-20Watts says he bought an Nvidia Shield to delay video, with an HDMI switch extracting optical audio for the M scaler; Netflix and Amazon sync but BBC iPlayer does not. Head-Fi, Apr 2020
2020-04-26Watts says connector impedance mismatch does not matter thanks to reflection cancellation and the FPGA's 15 nS anti-glitch, but the cable itself must be 75 ohms. Head-Fi, Apr 2020
2020-04-26Watts says TT2 and other DACs auto-switch dual BNC channels by data flag, but with DAVE the M scaler's left BNC must go to the bottom BNC pair. Head-Fi, Apr 2020
2020-05-01Watts doubts the JitterBug will help, since it stopped making a difference once he treated USB grounds with ferrites, and the M scaler has ferrites and galvanic isolation. Head-Fi, May 2020
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
2020-05-05Watts says data integrity plays no part, as long M scaler tests at -200dB never showed a bit error, but injected noise and processor activity can change the sound. Head-Fi, May 2020
2020-05-07Watts says a car battery is the best PSU but a power bank suffices, TT2 gains nothing, and a battery helps the M scaler by removing 2GHz ground return currents. Head-Fi, May 2020
2020-05-25Watts says 13.2V works with M scaler and TT2 on separate supplies, TT2 is supply-insensitive, and a battery on the M scaler removes the ground loop into the DAC. Head-Fi, May 2020
2020-05-26Watts says he does not need battery power at home because his Wave BNC cables give enough isolation that battery use brings negligible improvement. Head-Fi, May 2020
2020-05-27Watts says certified USB cables work at any length, he heard no difference among them, doubts audiophile cables, and found longer BNC cables better through reduced ground loop currents. Head-Fi, May 2020
2020-06-04Watts says TT2 matches Mojo and DAVE: -3dB is 3V RMS and four remote clicks down gives 1.89V RMS; with an M scaler set -4, as it attenuates 2.75 dB. Head-Fi, Jun 2020
2020-06-09Watts says the M scaler's thermal trip protects hands, its case bottom reflects FPGA die temperature rated to 85 C, and hours in a bag stayed below the trip. Head-Fi, Jun 2020
2020-06-25Watts says he uses his M Scaler on planes powered by a battery backup, but portability is limited by 12 watts of FPGA power dissipation. Part-Time Audiophile 28:08
2020-06-25Watts says the M Scaler runs about 525 DSP cores; a Hugo-sized M Scaler needs much better FPGAs, perhaps 10 years away; portable power efficiency is a major issue. Part-Time Audiophile 28:53
2020-06-25Watts names 1 million taps and the M Scaler, though a thumb-sized battery running 12 watts for eight hours would make a tiny device very hot. Part-Time Audiophile 30:56
2020-06-25Watts says doubling the sample rate quarters the timing error, only 2 bits, while the M Scaler matches a sinc function to better than 16 bits to reconstruct timing. Part-Time Audiophile 39:38
2020-06-25Watts says an M scaled 44.1 kHz recording beats an unscaled 192 kHz one, PCM timing is fully recoverable with enough processing, and he wishes recordings were 768 kHz. Part-Time Audiophile 40:28
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
2020-07-10Watts says he solved the DX amp's signal-dependent switching issue, a Dave DX amp is one to five years away, and explains frequency response and phase as depth cues. Head-Fi, Jul 2020
2020-07-27Watts says TT2 can stay on 24/7, DAC mode equals low gain at -5L, and an external amp often sounds warmer from distortion and capacitor dielectric absorption. Head-Fi, Jul 2020
2020-08-03Watts says M scaler clocks are a red herring: the DAC's 104.25 MHz clock and DPLL re-time the data, so 2 uS of input jitter causes no measurable error. Head-Fi, Aug 2020
2020-08-10Watts says 2 m BNC cables beat 1 m, solid-core 2 GHz ferrites help most, clip-on ferrites hurt with the M Scaler, and battery power breaks its ground loop. Head-Fi, Aug 2020
2020-08-11Watts explains that longer BNC cables or solid-core ferrites raise the RF impedance of the ground path from M Scaler to DAC, reducing circulating ground currents into the DAC. Head-Fi, Aug 2020
2020-08-13Watts estimates 2 m over 1 m BNC gives 25-33% of the ferrite gain, explains the ground loop, recommends Wave, and says other audiophile USB and BNC cables match or degrade certified ones. Head-Fi, Aug 2020
2020-08-17Watts says the BNC inputs on the DACs are not galvanically isolated, which is no problem with an M scaler because its BNC outputs are isolated. Head-Fi, Aug 2020
2020-09-07Watts advises running the M Scaler from the 12 V battery and not worrying about TT2, since breaking the current path once suffices; keep the battery isolated from ground. Head-Fi, Sep 2020
2020-09-09Watts calculates a battery on a desk has about 0.1 pF to ground, 796 ohms at 2 GHz; a Poweradd battery on the M Scaler nearly eliminates BNC cable differences. Head-Fi, Sep 2020
2020-09-13Watts confirms the Hugo M Scaler needs only 1 A at 12 V. Head-Fi, Sep 2020
2020-09-30Watts says overvoltage damage from out-of-spec PSUs voids warranty cover, many audiophile PSUs are unregulated, and the supplied TT2 and M Scaler PSU measured as quiet as a battery. Head-Fi, Sep 2020
2020-10-01Watts says 12 V is fine for the Hugo M Scaler; damage occurs only at 16 V and above. Head-Fi, Oct 2020
2020-10-29Watts says the M scaler and TT2 filter DSD, removing out-of-band noise with 220 dB attenuation and decimating to 705 kHz, which sounds better than DAVE's non-decimating DSD filters. Head-Fi, Oct 2020
2020-11-11Watts compares 1M-tap rectangular sinc, Kaiser and WTA filters by measurement and listening, explains how the WTA equation was tuned, and concludes algorithm matters more than tap length. Head-Fi, Nov 2020
2020-11-21Watts says latency is unavoidable as reconstruction must see the future; The Mandalorian sounds fantastic at 1M taps via Nvidia Shield; 12 W, just under 1 A at 15 V. Head-Fi, Nov 2020
2020-11-27Watts advises never upsampling before his DACs and says M Scaler research at 1M taps showed the WTA algorithm is 50 to 500 times more effective than conventional filters. Head-Fi, Nov 2020
2020-12-02Watts says he carries his M Scaler and uses it on flights with Hugo 2, finding it essential, though others may hear a smaller improvement. Head-Fi, Dec 2020
2020-12-03Watts shares his flight setups in business and economy class, with Hugo 2, M Scaler and a battery in his bag, good for 3 hours thermally. Head-Fi, Dec 2020
2020-12-27Watts says adding the M Scaler would be a bigger jump in separation, speed, warmth and flow, while TT2 is more refined than Hugo 2, and suggests trying both. Head-Fi, Dec 2020
2021-03-20Watts says an optical-only DAC has about 0.1pF to ground, while HMS to TT2 has about 2pF through the BNC isolators, fixed by battery-feeding HMS or solid-core 2GHz ferrites. Head-Fi, Mar 2021
2021-03-31Watts says CD player differences may be RF pickup via power amps, 2GHz ferrites or cutting loops fix M scaler to TT2 noise, notes a migraine; ADC work continues. Head-Fi, Mar 2021
2021-03-31Watts says the single BNC output on the M scaler is not galvanically isolated. Head-Fi, Mar 2021
2021-04-01Watts says disconnecting the M scaler charger avoids the source-M scaler-Dave loop, CD players inject RF into mains, and changing Dave's PSU invalidates the warranty. Head-Fi, Apr 2021
2021-04-02Watts says clip-on ferrites made his Hugo M Scaler sound brighter with poorer depth, suspects resonance with its internal 2GHz chip ferrites, and recommends solid-core ferrites. Head-Fi, Apr 2021
2021-04-02Watts says ferrites and inductors in the analog path cause level-dependent phase shift and hysteresis that upset transient timing, and a noisy M scaler FPGA inside a DAC is unwise. Head-Fi, Apr 2021
2021-04-03Watts says supply ferrites are fine, any trace of noise floor modulation seems audible so he expects desktop two-box, and stock cables with a battery M scaler matched Wave Stream. Head-Fi, Apr 2021
2021-04-20Watts says the scaler will treat a given input as pass-through, merely attenuating it by 2.76 dB to keep volume levels consistent. needs context Head-Fi, Apr 2021
2021-04-30Watts says 1 ohm below 3kHz trips thermals, the Aeon 2 closed gives the best depth, MQA's -40dB aliasing is unacceptable, and FPGA timing closure rules out 112.896 MHz clocks. Head-Fi, Apr 2021
2021-05-04Watts says audible changes need a science-based explanation, citing ADC-project sample rate converter tests (aliasing from -200 to below -350 dB) his son heard blind, and M scaler tempo perception. Head-Fi, May 2021
2021-05-10Watts says the M scaler exposes recording defects by being more transparent, and inter-sample clipping is handled by a -2.76dB gain reduction on all outputs, including pass-through. Head-Fi, May 2021
2021-05-18Watts says the M scaler and TT2 share identical DSD code, DSD's damage to transients and small signals cannot be repaired, but their DSD filters remove its HF noise. Head-Fi, May 2021
2021-05-23Watts says PGGB uses an apodizing, slow roll-off filter rather than sinc, so long taps cannot help its transient timing, and true offline sinc sounds like the M scaler. Head-Fi, May 2021
2021-06-04Watts says what matters is how many taps are Whittaker-Shannon, about 256M for 24-bit recovery; windowed or apodized sinc fails, and 64-bit float causes noise floor modulation. Head-Fi, Jun 2021
2021-07-19Watts says ADC interpolator tests showed noise floor modulation audible near -360 dB, explains M scaler ferrites and Wave cables' solid ferrites, and suggests battery power plus optical for isolation. Head-Fi, Jul 2021
2021-07-23Watts says the volume control output is aggressively noise shaped, not truncated or dithered, reproducing -301dB within +/-0.001 dB, and shows the M scaler truncator's -390dB noise floor. Head-Fi, Jul 2021
2021-08-04Watts says TT2 draws a steady 12 to 13W, its standby is fine, and the M scaler keeps one LED on in low power mode, dimmable via both DX buttons. Head-Fi, Aug 2021
2021-08-08Watts says the Primephonic app seems to upsample, advises checking the native rate, explains sample-rate-change clicks, and says the clicks cannot damage the M scaler or DAC. Head-Fi, Aug 2021
2021-08-19Watts says Opto-DX isolates fully only with batteries on both sides, and calls his volume truncation noise-shapers subjectively lossless but not bit perfect, a claim he is researching. Head-Fi, Aug 2021
2021-08-29Watts recommends a 768kHz ADC, plans pulse array ADC tests, favors digital volume over analog, and says grounding via Dave shorts its isolation; ground elsewhere, battery-power, or use a resistor. Head-Fi, Aug 2021
2021-09-09Watts says the M Scaler improves tempo, pitch, timbre and separation, while WTA filtering above 16FS has so far only improved clarity, soundstage and starting and stopping of notes. Head-Fi, Sep 2021
2021-10-05Watts says to maintain the sample rate, current EQ and 64-bit float are not transparent; in M Scaler tests his 11th-order truncation noise shaper beat rectangular, triangular and pseudo-Gaussian dither. Head-Fi, Oct 2021
2021-10-18Watts covers phone RF loops with Mojo, USB cable dressing, 2G buzz, Netflix audio, USB galvanic isolators in desktop DACs and M Scaler, and why brighter cables mean more noise. Head-Fi, Oct 2021
2021-10-21Watts says longer M Scaler BNC cables sound better by suppressing 2GHz ground current, 2m beats 1m markedly, his PowerAdd supplies while charging, and the app sends 192k. Head-Fi, Oct 2021
2021-10-22Watts says supplied BNC cables are starters; 2GHz ferrites, Wave cables or battery power cure ground currents; Qutest uses Mojo's output stage; M Scaler was developed with TT2 and DAVE. Head-Fi, Oct 2021
2021-11-30Watts lists his flight and hotel kit, says measurements catch gross flaws, and that the brain compensates for transducer distortion but not digital errors like NFM and timing errors. Head-Fi, Nov 2021
2021-12-06Watts says HQPlayer and PGGB give no idea of M scaler performance, since many taps with the wrong algorithm give the wrong result, and only WTA minimizes transient timing error. Head-Fi, Dec 2021
2021-12-11Watts says 705/768 files are handled like pass-through: volume-scaled to match other inputs, then aggressively noise shaped to 24 bits for the BNC outputs, so 32-bit inputs convert transparently. Head-Fi, Dec 2021
2022-01-04Watts says Dave drives the Susvara to 92 dB SPL, voltage limited, and gives volume limits (+4 solo, +7 with M scaler); preferring an amp means preferring distortion. Head-Fi, Jan 2022
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
2022-01-06Watts says the M scaler is 1M taps at 705/768k so only half the taps are used at 352/384, and that tape bias and amplifiers also degrade transient timing. Head-Fi, Jan 2022
2022-01-10Watts says the Nvidia Shield can delay video up to 1 second to match 1M-tap audio latency, raising his appreciation of film, but quality is not all about taps. Head-Fi, Jan 2022
2022-01-13Watts explains tempo perception depends on note starts and stops; timing modulation harms separation so the loudest instrument dominates; headphone sensitivity is rated at 1mW while volume is voltage. Head-Fi, Jan 2022
2022-01-28Watts confirms 44.1 kHz goes to 705.6 kHz on dual BNC, and says the chart in question was not his since manuals come from Chord. Head-Fi, Jan 2022
2022-01-31Watts says the 768 kHz coax capability is so that it can be run with the M Scaler. needs context Darko.Audio 4:25
2022-01-31Watts says some users pair it with an M Scaler, he flies with Hugo 2, an M Scaler and a power bank, and better FPGAs might enable a Mojo-type scaler. Darko.Audio 4:29
2022-01-31Watts says a scaler that small is more like 10 years away, so 768 kHz support is sensible; he did his listening tests with the M Scaler as source. Darko.Audio 5:16
2022-01-31Watts ties transient timing to the WTA filter: 1 million taps in M Scaler, 40 thousand in Mojo 2 using forty DSP cores per channel; samples are 22 microseconds apart. Darko.Audio 9:24
2022-01-31Watts says two or three years ago he found amplitude-dependent phase shift is audible as suppressed depth, while investigating why 1 million taps beat DAVE's 164 thousand for depth. Darko.Audio 24:34
2022-01-31Watts presents Mojo 2: coupling capacitor removed, new noise shaper, and a UHD DSP EQ he says passes -301dB amplitude, phase and NFM transparency tests that 64-bit DSP fails. Head-Fi, Jan 2022
2022-02-01Watts answers Mojo 2 questions: 2G buzz mitigation, dual-data ring contact, 0.35S latency, DSP cores, 9 hours 11 minutes battery on USB, and 99.5dB SPL into HD800. Head-Fi, Feb 2022
2022-02-09Watts says the power bank would run Qutest about 100 hours per charge but is too powerful for flying and lacks 12v for M scaler; he suggests a Krisdonia 25000mAh. Head-Fi, Feb 2022
2022-02-13Watts says battery power on the M Scaler removed his need for ferrited BNC cables, and Wave cables removed the need for batteries, both cutting GHz ground currents into DAVE. 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
2022-02-20Watts says USB latency is insignificant against WTA latency, DoP works to DSD256 on Linux and macOS, native DSD512 needs Windows ASIO, and 44.1/16 with M Scaler beats DSD512. Head-Fi, Feb 2022
2022-02-21Watts says good 16-bit 44.1 via the M Scaler beats DSD512, which sounds soft and flat like all DSD, consistent with DSD's small-signal, timing and noise floor modulation problems. Head-Fi, Feb 2022
2022-02-21Watts says putting the source and M scaler on one battery keeps source RF from the DAC; the M scaler's USB isolation exists only to cut noise reaching the DAC. Head-Fi, Feb 2022
2022-02-26Watts reports 6.5 hours powering his M Scaler from a new power bank, warns against its DC out for Hugo 2, and explains annealing his DIY PTFE-insulated cable. Head-Fi, Feb 2022
2022-03-19Watts says conventional EQ adds noise floor modulation and collapses the soundstage as small signals lose amplitude accuracy, and recounts puzzling over why an M Scaler markedly improves depth. MFG Audio Reviews 30:09
2022-03-19Watts says the M Scaler's depth gain cannot come from small signal amplitude, set by quantization and noise shaping, so depth must involve timing; he tested a detuned noise shaper. MFG Audio Reviews 30:53
2022-03-19Watts says above 64FS timing becomes almost unimportant, 768 kHz recordings would make scalers unnecessary, and the one 768 kHz recording he heard sounds like an M Scaler. MFG Audio Reviews 52:53
2022-03-19Watts says Mojo and Hugo 2 lack galvanic isolation and that galvanic isolation in general is about 99% effective; optical helps with noisy servers, and his MSI desktop sounds much better on optical. MFG Audio Reviews 56:58
2022-03-22Watts lists his systems: Hugo M Scaler, TT2 and B&W 803 D3 at home; M Scaler, DAVE and DCA Stealth in the office; M Scaler, TT2 and Stealths for flying. article, Mar 2022
2022-03-31Watts says 32-bit integer reaches TT2's FPGA but 32-bit float is unsupported; he runs TT2 at +7 via M scaler, and Utopia needs high gain, low gain suiting IEMs. Head-Fi, Mar 2022
2022-04-07Watts says M scaler depth gains led him to test phase shift with amplitude (2uS, 100nS, 10nS errors), so modules must now pass -301 dB in amplitude and phase. Head-Fi, Apr 2022
2022-04-25Watts says TT2 and M Scaler can be stacked, but are better apart with Wave or solid-ferrite BNC cables; use high gain unless IEMs hiss; avoid wireless subwoofer links. Head-Fi, Apr 2022
2022-04-26Watts advises high gain into a power amp, keeping units on Wave cables apart to avoid capacitive coupling and cable ends touching, and says TT2 tolerates running warm continuously. Head-Fi, Apr 2022
2022-04-26Watts says the WTA filter minimizes timing modulation but cannot eliminate it, nor can an M Scaler; his algorithm maximizes accuracy with limited taps, and Mojo's FPGA is custom coded. Audio Force 11:37
2022-04-26Watts says Mojo 2's dual port is only for use with an M Scaler, that a portable M Scaler needs 3 nm FPGAs probably 10 years away, and that he tested Mojo with one. Audio Force 16:02
2022-04-26Watts says he does not expect people to pair Mojo with an M Scaler, though they might; cheaper or simpler scalers will come, in 2 years or 10, and the input cost little power. Audio Force 16:50
2022-05-03Watts says something gives a small improvement, judged with two DAVEs via the DX output, far less than an M scaler; he notes his independence and refers pricing to Chord. needs context Head-Fi, May 2022
2022-05-07Watts prefers optical over coax, uses regular optical cables plus a 2m Lifatec optical cable for 192k and Wave Stream BNC cables on the M scaler, and sees no benefit in I2S or balanced. Head-Fi, May 2022
2022-05-14Watts says WTA taps split between future and past; M scaler video mode uses 98,304 future and 507,904 past taps (606,208 total); ASIO native USB allows DSD512, with fewer pops. Head-Fi, May 2022
2022-05-23Watts says the DX protocol's volume data is for future DAC power amps without volume controls, and DAVE between an M scaler and TT2 would just pass data through. Head-Fi, May 2022
2022-06-15Watts says the M scaler regulates input to 5 V, 16 V could damage it, and he will try a Krisdonia at 9 V, preferring warmer sound to RF brightness. Head-Fi, Jun 2022
2022-07-06Watts says the Hugo M Scaler's extra noise at 2x and 4x is deliberate Gaussian dither that sounds better, 16x noise is unchanged, and Chord DACs remove its jitter. Head-Fi, Jul 2022
2022-07-07Watts confirms no Hugo M Scaler firmware change has affected audio or measured performance; once in production, performance is frozen and updates are for control, interface, reliability or production only. Head-Fi, Jul 2022
2022-07-11Watts says M Scaler DSD handling matches Hugo 2 and TT2, converting DSD64 through DSD512 to 705 kHz 24-bit; he also praises forum civility and calls audiophile patents marketing. Head-Fi, Jul 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
2022-07-12Watts says it is unknown whether streaming services send a true stereo track or the player downmixes, and he now prefers streaming to Blu-ray since it allows full M scaling. Head-Fi, Jul 2022
2022-07-12Watts says 16/44 gains more from M scaling but 24/192 M scaled is closer to the original; his goal is 24/48 matching 24/192, needing transparent 24-bit re-quantization at 48 kHz. Head-Fi, Jul 2022
2022-07-14Watts says the M Scaler is essential, PGGB sounded like an apodizing filter, and the M Scaler reconstructs transient timing beyond 16 bits, passing -301 dB via dual BNC. Head-Fi, Jul 2022
2022-07-19Watts says the amp is in the background, old recordings involve via M Scaler and DAVE, and his Blumlein test recordings showed ADC losses: less depth, softer transients, warmer balance. Head-Fi, Jul 2022
2022-07-21Watts says non-supplied PSUs void Chord's warranty, linear supplies lack 100 kHz to 10 GHz RF filtering, and transient timing reconstruction differs from transient response, which only listening tests reveal. Head-Fi, Jul 2022
2022-08-19Watts says going from DAVE's 164,000 taps to the Hugo M Scaler's 1 million made a bigger difference than expected, opening the soundstage, and that 16-bit accuracy is not enough. AVstore 6:55
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 the intent was Chord DACs; the 96 and 192 kHz outputs were mainly for recording, e.g. 44.1 run at 'one seven four kilohertz', though universality helps. AVstore 25:51
2022-08-19Watts says the M Scaler's big benefits need 768 kHz, he can't think of any DAC running 384 kHz over BNC, and some 192 kHz buyers later switched to Chord DACs. AVstore 26:46
2022-08-19Watts says the M Scaler is separate because its processing creates gigahertz ground-plane noise that is very hard to filter inside a DAC, so an external scaler will always help. AVstore 29:50
2022-08-19Watts says no interpolation filter is perfect, the M Scaler included: past and future music modulates each transient leaving the filter, making it slightly early or late. AVstore 31:45
2022-08-19Watts says the purpose is emotional engagement with music, which requires making it easy for the brain to understand, and that this is the M Scaler's objective. AVstore 37:23
2022-08-19Watts says the extra jitter generated by the scaler is not a problem at all for Chord DACs. AVstore 39:08
2022-08-19Watts says DAVE measures slightly better with the M Scaler, with slightly lower distortion and noise and no jitter difference, because DAVE's WTA filter does no work and 80 percent of the chip sits idle. AVstore 39:21
2022-08-19Watts says he prefers optical into the M Scaler; USB can match it or sound harder, brighter and flatter; BNC is technically worst, lacking galvanic isolation. AVstore 41:06
2022-08-19Watts says the M Scaler's BNC outputs have a galvanic isolator, giving near-optical standard, but about three picofarads (first said two) is tens of ohms at gigahertz, so he also added ferrites and filters. AVstore 42:06
2022-08-19Watts says to use optical as the reference since it is perfectly galvanically isolated, and its slightly higher jitter than BNC does not matter with Chord DACs. AVstore 42:56
2022-08-22Watts explains a tap as a sample times a WTA coefficient, summed in an accumulator; the M Scaler uses 63,488 original samples per interpolated sample, going 1FS to 16FS. Head-Fi, Aug 2022
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 most people hear a substantial A-B difference with the M Scaler, but its real benefits are musical: timbre variation, pitch discrimination and more enjoyment of music. The Source AV 6:06
2022-09-18Watts says that once you get used to the sound of the scaler you cannot live without it. The Source AV 6:47
2022-09-18Watts says he takes an M Scaler with him when flying, even in economy, packed in a bag. The Source AV 6:53
2022-09-18Watts says the cello sounded about 2.5 meters away on DAVE, about 2 on Hugo 2, about two with M Scaler (as transcribed), half a foot on conventional DACs. The Source AV 19:00
2022-09-18Watts says the WTA algorithm that sets the M Scaler's WTA filter uses his equations with five variables, which are listened to, modified and honed to a sweet spot. The Source AV 22:00
2022-09-18Watts says the closed-back Stealth shuts out noise on about 300 flying hours a year, and Stealth, Hugo 2 and M Scaler performance would have seemed unbelievable in the 1980s. The Source AV 31:18
2022-10-01Watts says that when running with the M scaler the limit is +10dB, where a 0dBFS signal clips into a nominal 8 ohm load. needs context Head-Fi, Oct 2022
2022-10-12Watts says it creates harmonic and anharmonic distortion, calls the latter really nasty, and says only the WTA filter is designed to minimize these; the M Scaler adds computing power. Upscale Audio 3:50
2022-10-12Watts says the M Scaler improves performance, and that improving transient reconstruction accuracy through the filter's design took thousands of listening tests. Upscale Audio 4:25
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
2022-12-10Watts says a 5m KabelDirect and 2m Lifatec plastic optical cable both work at 192k and sounded identical on the M Scaler in careful AB tests. Head-Fi, Dec 2022
2022-12-13Watts says audiophile USB cables add RF or sound identical, optical (KableDirekt) is best, a phone or battery laptop is the reference source, and Wave Stream cables help. Head-Fi, Dec 2022
2023-01-04Watts reports the Bixpower BP90-12v ran an M Scaler nearly 10 hours and clearly beat the Krisdonia on depth and separation, the Poweradd less clearly. Head-Fi, Jan 2023
2023-01-06Watts says with a Poweradd powerbank and optical on the M Scaler, quality BNC sounded like Wave Stream, since no ground currents can reach the DAC's ground plane. 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
2023-01-12Watts says star earthing's 2uH is 25,000 ohms at 2 GHz; adaptors are fine but long cables should be 75 ohm, and his short 50 ohm cables never drop out. Head-Fi, Jan 2023
2023-01-12Watts says he uses positive phase and sets the M scaler's HF filter off with DAVE, and that absolute phase differences are small and depend on recording and transducer. Head-Fi, Jan 2023
2023-01-16Watts turns DAVE's HF filter off with the M scaler, doubts a Hugo 2-priced portable scaler-DAC by 2032, sets crossfeed to max, and says more taps add depth. Head-Fi, Jan 2023
2023-01-19Watts says his point concerned the Hugo M scaler's 24-bit outputs, not DACs, and noise shaper size depends on type and task, though all need -301 dB performance. Head-Fi, Jan 2023
2023-02-04Watts says others use standard math and trust their brand; with the M Scaler's million taps he can guarantee 16-bit reconstruction accuracy between samples. Dusty Audio 43:46
2023-02-04Watts says with his MSI laptop into the M Scaler and Dave, optical and USB sounded the same so he used USB, before his son built him a high-performance computer. Dusty Audio 1:07:10
2023-02-04Watts says his 800 W desktop's USB sounded significantly worse than optical into the M Scaler; optical is the reference because no current flows into the DAC. Dusty Audio 1:07:51
2023-02-05Watts says his phone feeds USB straight into the M Scaler, then into Hugo, driving Dan Clark Audio Stealths, which he calls really good sounding closed-back headphones. Soundnews 1:40
2023-02-05Watts says playback through M Scaler and Hugo 2 was surprisingly close to the original sound; the recording used a Blumlein pair of ribbon microphones. Soundnews 3:08
2023-02-05Watts says the unprocessed recording went straight into the ADC; playback matched in frequency response but sounded warmer and softer than live, though he considered the Stealths slightly bright. Soundnews 3:27
2023-02-05Watts says Japanese reviewers played their own music at a Tokyo show on 803s, a pre-Ultima Chord amplifier, DAVE and an M Scaler; show demos normally sound worse. Soundnews 7:06
2023-02-05Watts says separate I2S clock lines bring no benefit and three cables add ground noise; he always prefers optical, with galvanically isolated BNC from the M Scaler nearly matching it. Soundnews 48:58
2023-03-01Watts says the M Scaler needs no warm-up, Hugo 2's in-flight change was ear pressure, describes flying with his battery rig and thermal trip, and says battery plus optical isolates. Head-Fi, Mar 2023
2023-03-01Watts says 2pF across the M Scaler's USB and BNC isolation gives about 80 ohms at 2 GHz, letting current reach DAVE's ground plane; optical may beat USB, source depending. Head-Fi, Mar 2023
2023-03-02Watts says scalers are separate units to keep FPGA noise from the DAC, as the Hugo M Scaler injects 12A of noisy current into its ground plane. Head-Fi, Mar 2023
2023-03-03Watts says a Hugo M Scaler in a Mojo-size case would run at 100 deg C, and fanless operation needs a fivefold FPGA improvement without rising cost. Head-Fi, Mar 2023
2023-03-03Watts says subjectivism trumps objectivism but listening must be rigorous, part changes never degrade performance, M Scaler gains were clearer with tube amps, and he writes all FPGA code. Head-Fi, Mar 2023
2023-03-16Watts says DAVE's DSD+ mode filters without decimating, yet the Hugo M Scaler's DSD conversion sounds better because its filtering is more effective, and explains decimation. Head-Fi, Mar 2023
2023-03-19Watts says phase shift with amplitude, found after the M scaler work, affects depth; tuning Mojo's noise shaper for minimal -301dB phase error led to Mojo 2's UHD DSP. Head-Fi, Mar 2023
2023-03-26Watts says licensing the algorithm is possible but a business decision; software like PGGB cannot run in real time, which matters for streaming and video, where he uses scalers. Eric's Hi-Fi 10:28
2023-03-26Watts says his NVIDIA streamer allows a one second video delay so he can use an M Scaler; original PGGB files sounded nothing like it, and apodizing cannot reconstruct transients. Eric's Hi-Fi 11:13
2023-03-26Watts says he has not heard the latest PGGB version, the original sounded nothing like an M Scaler, and he has no experience of HQPlayer. Eric's Hi-Fi 12:01
2023-03-26Watts says Qutest and TT2 sound the same on a car battery as on the supplied switch mode supply, except TT2 with an M Scaler; better supplies would add RF. Eric's Hi-Fi 19:18
2023-03-26Watts says M Scaler output jitter is irrelevant because his DACs eliminate it; it was never designed for low jitter, and 2 microseconds of jitter has no measured impact. Eric's Hi-Fi 24:19
2023-03-26Watts says M Scaler jitter is nanoseconds, so that criticism is irrelevant; DAVE measured extraordinarily for him and HiFi News, recalled as 0.0000 four or five zero seven percent distortion. Eric's Hi-Fi 25:05
2023-03-26Watts says DAVE measures better than any DAC he has seen, yet others using an APx555 differ; one manufacturer's terrible TT2 and M Scaler results came from ground loops. Eric's Hi-Fi 25:47
2023-03-26Watts says non-audiophiles found music slower with the M Scaler; he agrees, since removing mechanical, disjointed jerkiness restores natural flow that otherwise seems faster. Eric's Hi-Fi 38:17
2023-04-03Watts declines to give a tap count because thermal considerations may change it, but says it is substantially more than the M Scaler's. needs context Amplify Audio 2:29
2023-04-03Watts says before the M Scaler he thought depth depended only on small-signal amplitude; raising WTA tap length had never changed depth before, suggesting timing matters for depth. Amplify Audio 7:04
2023-06-18Watts says an isolated power bank or Wave cables break the M Scaler's GHz ground loop, longer standard BNC sounds better via common mode inductance, and Krisdonia sounded worse. Head-Fi, Jun 2023
2023-06-19Watts says an unnamed project started in 2018 with a first PCB in Feb 2019, his longest; he flies with a Bixpower, Hugo 2, Hugo M Scaler and DCA Stealth. needs context Head-Fi, Jun 2023
2023-06-21Watts says the M Scaler passed EMC tests, the reported problem is likely 50 to 104 MHz rather than GHz, and suggests trying stock or Belden BNC cables. needs context Head-Fi, Jun 2023
2023-06-25Watts says a better DAC makes changes easier to hear, and suspects an owner's fault is the FPGA boot sequence tripping the M Scaler's internal PSU, which Chord should fix. Head-Fi, Jun 2023
2023-07-03Watts says powering the M Scaler after the source can break USB handshaking, so power the scaler or DAC first; he also reflects on reputation and CanJam Singapore. 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
2023-08-22Watts disputes PGGB's pure-sinc claims, says coefficients must be windowed, and suggests listening for bass pitch, separation, focus and timbre variation. Head-Fi, Aug 2023
2023-08-25Watts says early Decca recordings have speed he attributes to aliasing and timing, suspects modern half-band ADC decimation, and says early PGGB sounded poorer than the Hugo M Scaler. Head-Fi, Aug 2023
2023-08-26Watts explains as a trade member he cannot rank rivals' filters, would never falsely call one worse, and criticizes PGGB's marketing claims and implementation. Head-Fi, Aug 2023
2023-09-14Watts explains why Mojo 2's EQ is loss-less rather than bit perfect, advises against source upsampling, and says an M scaler improves Mojo 2 though algorithm matters more than taps. Head-Fi, Sep 2023
2023-10-01Watts says that when first hearing the M Scaler open up the soundstage, he thought engineers recording at 48 kHz never heard this at all. The Source AV 16:56
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
2023-11-02Watts says an asymmetric FIR with short pre-ringing and long post-ringing beats short symmetric filters, as in the Hugo M Scaler's video mode. Head-Fi, Nov 2023
2023-11-29Watts says the DAVE update fixed occasional dropouts with the M Scaler in about 1% of units by improving SPDIF error tolerance, with no sound change. Head-Fi, Nov 2023
2023-11-30Watts says a Roon resync delay fixes USB sample-rate-change clicks by flushing buffers, and optical from the streamer avoids them, limited to 192k, often with better sound. Head-Fi, Nov 2023
2023-12-22Watts says that traveling with TT2 and Hugo M Scaler, he stacked or separated them by hotel layout and never noticed a sound-quality difference. Head-Fi, Dec 2023
2024-01-07Watts says 16FS is the interpolation sweet spot (1.3uS vs 2.6uS timing at 8FS for 48kHz), adding more 200T FPGAs is the economic path, and a battery laptop via optical is hard to beat. Head-Fi, Jan 2024
2024-02-15Watts says NFM sounds etched and brighter but degrades focus, the DPLL handles source PSU noise via optical, and battery plus optical on the M Scaler removes the ground loop. Head-Fi, Feb 2024
2024-02-22Watts says galvanic isolation fails at GHz via capacitance, optical breaks the link, and an LPS on TT2 would be a downgrade that sounds etched due to no RF filtering. Head-Fi, Feb 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
2024-04-17Watts 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
2024-05-10Watts says the changes in this unit are quite a lot compared to the M Scaler. Reactcore 9
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 the project was also research on interpolation; Hugo M Scaler had sinc performance to 16-bit, a target he thought unreachable when he identified the flaw in the 1980s. ConvinceMeAudio 7:44
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 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
2024-05-17Watts 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
2024-06-01Watts explains transients and localization, how crossfeed narrows headphone width, and ranks rectangular, triangular and pseudo-Gaussian dither below noise shaping, best for depth. Head-Fi, 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 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
2024-06-28Watts 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
2024-07-01Watts lists DAVE's three DSD options with a Hugo M Scaler; the scaler's DSD filter (better than 200dB rejection) sounds best, and he studies decimation limits via the ADC project. Head-Fi, Jul 2024
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 in the 1980s he calculated that 16-bit timing accuracy needs nearly a million taps for a 16 times oversampled filter, the key to the Hugo M Scaler. HIFICLUB 9:54
2024-07-12Watts says FPGAs could run interpolation filters by 1999 and a million taps by 2015, leading to the Hugo M Scaler; his role was more taps and a better algorithm. HIFICLUB 11:31
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 the M Scaler was noticeably sensitive to BNC cables (ferrites helped) and sources, from current injected into the DAC despite galvanic isolation; a battery power bank solves it. HIFICLUB 45:42
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 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
2024-07-18Watts 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
2024-07-25Watts 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 uses the Hugo M Scaler when flying and that people think he is crazy for it. Hifi Pig TV 3:30
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 security in Vietnam took a unit away for five minutes, yet nobody minds the big Hugo M Scaler on flights; he cannot travel without it. Hifi Pig TV 4:13
2024-08-12Watts says inputs differ only through source RF noise: optical is the reference, USB has ground ferrites, and coax is most sensitive, hence galvanic isolation on the Hugo M Scaler. Head-Fi, Aug 2024
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 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
2024-10-03Watts 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
2024-10-06Watts says the best pre-amp or power amp is none, cites TT2 sounding the same into an 8 ohm load, and says the large-power DX DAC concept is not dead. Head-Fi, Oct 2024
2025-01-04Watts says the M Scaler regulates input to 5v, so falling BixPower voltage neither changes sound nor risks damage; he recommends the supplied PSU or BixPower. Head-Fi, Jan 2025
2025-01-08Watts says valve amps easily sound musical but bipolar can sound better, estimates 38 to 76 hours of Hugo M Scaler use per car battery, and says measurements ignore transients. Head-Fi, Jan 2025
2025-01-09Watts describes a transient reconstruction test giving the M Scaler 22-bit accuracy but says raw numbers miss perception, and rejects an extra amp since DAVE drives Stealth to ear-damaging levels. Head-Fi, Jan 2025
2025-02-10Watts says to use TT2 filter 1 or 2 (he uses 2) with the Hugo M Scaler, not 3 or 4. Head-Fi, Feb 2025
2025-03-17Watts advises reducing the setting by some dB, suggesting +7dB as the limit with a Hugo M Scaler. needs context Head-Fi, Mar 2025
2025-03-27Watts says DoP works on all inputs within rate limits (optical DSD64, coax up to DSD128), conversion keeps DSD's 6dB overload, and test modulators show DSD is technically unacceptable. Head-Fi, Mar 2025
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 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
2025-05-12Watts lists benefits of more taps and WTA tweaks (bass, staging, separation, fatigue, note starts and stops); at 1 million taps the Hugo M Scaler reaches identical sinc values. Audiophile Junkie 14:19
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 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 no, he always uses the M Scaler whenever he is listening. The Source AV 15:39
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 accurate transients remove a mechanical quality and reveal musicians' timing interplay as instruments are better focused; some hear little difference with the M Scaler, others find it essential. The Source AV 16:52
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
2026-03-17Watts says only sinc coefficients reconstruct perfectly, a million-tap sinc filter guarantees better than 16-bit reconstruction, and the Hugo M Scaler achieved that. ecoustics 13:56
2026-03-17Watts says DAVE's filter is 164 thousand taps; an M Scaler adds a million taps, converting 48 kHz to 768 kHz (16 times), and DAVE then upsamples to 2048 times. ecoustics 23:40
2026-03-17Watts says the signal reaches analog via the noise shaper; a scaler replaces the DAC's front-end filter, and every DAC from a $600 Mojo to a $20,000 DAVE benefits. ecoustics 24:23
2026-03-17Watts says the Hugo M Scaler's 192 kHz outputs feed any DAC, but the real benefit comes only at 768 kHz, an important rate whose technical reasons he leaves aside. ecoustics 25:10
2026-03-17Watts says 768 kHz recordings he has heard sound as if played through an M Scaler: very spacious, with tight, well-defined bass and good timbre variation. ecoustics 26:03
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 each of the WTA equation's five factors had to be set by ear to within ten parts per million, and he did not understand why a million taps was so sensitive. Audio Force 10:45
2026-03-24Watts says at New York CanJam, owners of DAVE and the M Scaler all said it was a much bigger change than they expected. needs context Audio Force 21:35
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
2026-08-30Watts says that after the Hugo M Scaler, more taps (1,000 in 1999) and a better WTA kept sounding better; a million taps gives 16-bit reconstruction, but more is needed. The Source AV 6:00
2026-10-02Watts says M Scaler impressions vary with systems; Class D amps or poor speakers hide it, while DAVE, Hugo 2, TT or Mojo 2 with headphones give full control. HiFi Buys 2:24:19
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 doing even an M Scaler's processing this way takes huge computing time, so claimed results do not add up for him. Distorsiuni Interioare 37:16
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
2026-10-17Watts says hardware was a problem but the first part was research into why interpolation filters change the sound, which began in 2018 when the M Scaler was finished. article, Oct 2026
2026-10-17Watts says after the M Scaler he wanted to know how many taps give the best sound, and whether it would take 10 million or 100 million. article, Oct 2026
2026-10-17Watts describes tuning the five WTA equation variables to within 10 parts per million by listening, finding a sweet spot with the million taps. article, Oct 2026
2026-10-17Watts says he put a number on when the effects disappear, used it to compute the taps needed for a good approximation to the original signal, and asks how many that is. article, Oct 2026

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