Mojo 2: everything he said

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

• 2022-01-31Watts says COVID slowed the project because of parts shortages, and that it started as a design project in 2018, making it four years old. Darko.Audio 1:06
• 2022-01-31Watts says the design went through five PCB versions, not coding versions, and the longer-than-expected schedule let him make more improvements. needs context Darko.Audio 1:25
• 2022-01-31Watts says the brief required Poly compatibility; a planned second USB-C port for charging conflicted with the optical input, and he refused to drop optical. Darko.Audio 2:22
• 2022-01-31Watts says they were left with a single USB-C port. needs context Darko.Audio 3:07
• 2022-01-31Watts agrees, noting the original Hugos and Mojos did the same, and says the 3.5 mm connector's advantage is that it is very small. Darko.Audio 3:34
• 2022-01-31Watts says 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 says noise floor modulation impairs instrument separation and timbre; his DACs including Mojo 2 and Mojo show none measurably, unlike all others; the third factor is transients. Darko.Audio 8:26
• 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 the change is evolutionary: original Mojo was 38 thousand taps, he improved the filter and updated its internal architecture, and the improvements are subtle. Darko.Audio 12:58
• 2022-01-31Watts says the analog stage is nearly unchanged; the supply changed so Mojo 2 runs without the battery, which original Mojo needed to keep supply noise from the amplifier. Darko.Audio 13:48
• 2022-01-31Watts says he improved the charging supply for dynamic currents and added separate regulation for better PSRR, improving performance even with the battery, and introduces intelligent desktop mode. Darko.Audio 14:39
• 2022-01-31Watts says that in desktop mode, once the battery is fully charged it is physically disconnected. Darko.Audio 15:26
• 2022-01-31Watts says the unit can run three or four years on one charge with the battery disconnected, avoiding wear, and many people used Mojo One on desktops. Darko.Audio 15:38
• 2022-01-31Watts says constant trickle charging on a desktop wears a battery out; desktop mode removes it, so the supply and PSRR had to work harder to replace the battery. Darko.Audio 15:59
• 2022-01-31Watts says desktop mode brings neither gain nor loss; mains connection via the charger always costs a little, pure battery sounds best, and he minimized that drop. Darko.Audio 16:39
• 2022-01-31Watts says one reason for dropping line-level startup was users forgetting it, powering up, plugging in IEMs and blowing their ears out. Darko.Audio 17:18
• 2022-01-31Watts says other reasons were simplifying setup alongside the new DSP and that Mojo's 3 volts is too much for many amplifiers, hence Qutest's 1, 2 and 3 volt settings. Darko.Audio 17:48
• 2022-01-31Watts says yes, and that his Mojo 2 presentation publishes what each volume color means in voltage. Darko.Audio 18:48
• 2022-01-31Watts says COVID-era listening tests revealed very small audible effects, so the DSP had to reproduce -301 dB perfectly in phase and amplitude, requiring a different core. Darko.Audio 26:13
• 2022-01-31Watts says he built a 104-bit DSP core rather than the usual 64 bits; it passed -301 dB amplitude but failed phase until each node got a noise shaper. Darko.Audio 26:59
• 2022-01-31Watts says the DSP then showed zero phase shift at -301 dB, and it sounded better once the noise shapers were in. Darko.Audio 27:50
• 2022-01-31Watts says Mojo 2 replaces the coupling capacitor with Hugo 2's DC servo, losing Mojo's slightly soft, warm sound but becoming fundamentally more transparent. Darko.Audio 34:59
• 2022-01-31Watts says removing the capacitor led him to add EQ for cheaper headphones that are too bright or lack bass, which raised how to make EQ actually work. Darko.Audio 35:47
• 2022-01-31Watts says EQ fails on transparency because adjusting it audibly degrades sound; lossless DSP lets you change bass or warmth without degrading musicality or transparency. Darko.Audio 36:26
• 2022-01-31Watts says the improved noise shaper gave better soundstage and detail, and bass is tighter; Mojo's power limit forced him to throttle the FPGA. Darko.Audio 37:17
• 2022-01-31Watts says Mojo 2 runs the FPGA at full capacity, needing 200 milliwatts more, which he saved elsewhere, for example in the relay and circuit efficiency, without losing performance. Darko.Audio 38:02
• 2022-01-31Watts says the extra 200 milliwatts funded the digital DC servo, a better WTA filter and noise shaper, and the EQ DSP core; the noise shaper improves depth and detail. Darko.Audio 38:46
• 2022-01-31Watts says the listener should also have heard significantly better depth. needs context Darko.Audio 39:31
• 2022-01-31Watts lists the EQ: 20 Hz and 20 kHz peak filters of +/-9 dB, a +/-9 dB bass shelf from 125 Hz to DC, and a 3-20 kHz treble shelf. Darko.Audio 39:52
• 2022-01-31Watts says the peak filters use a Q of 0.5, so +6 dB at 20 Hz gives +3 dB at 40 Hz, following a first-order characteristic. Darko.Audio 40:45
• 2022-01-31Watts says a shelf filter has no Q in a biquad; it has a fixed slope designed to be as sharp as a biquad allows. Darko.Audio 41:07
• 2022-01-31Watts says peak filters cover 20 Hz and 20 kHz and shelves cover bass and treble, chosen after headphone plots showed mass-market Japanese headphones rolling off from 125 Hz. Darko.Audio 41:29
• 2022-01-31Watts says the bass controls fix low-frequency problems, high-end headphones are flat, and cutting the treble shelf 2 or 3 dB while boosting 20 kHz 3 dB tames sibilance. Darko.Audio 42:13
• 2022-01-31Watts says to adjust the shelf by a couple of dB and the 20 Hz filter by about 1 dB to make it sound warmer and softer. needs context Darko.Audio 43:03
• 2022-01-31Watts says another buyer calls Mojo too soft and warm; analog tone controls and conventional DSP degrade performance, while this approach adjusts response without harming transparency. Darko.Audio 44:00
• 2022-01-31Watts says the Harman curve suits headphone makers, but his EQ was informed by plain frequency response, mainly bass; it cannot fix a resonance at 9.52 kHz. Darko.Audio 44:48
• 2022-01-31Watts says with the DSP core in place crossfeed cost no gates, which matter for Mojo's power dissipation; he cannot use headphones without it, though some hear little difference. Darko.Audio 47:26
• 2022-01-31Watts says formula, coefficients and four settings match DAVE, Hugo 2 and Hugo one; only implementation differs, using biquads instead of Hugo 2's dedicated serial DSP core. Darko.Audio 48:10
• 2022-01-31Watts says it is a background, long-term project, commercially less important than Mojo 2, that keeps being set aside, but he is working on it today. needs context Darko.Audio 49:47
• 2022-01-31Watts says four years of development for Mojo 2 is a little untypical; a product normally takes two to three years. Darko.Audio 50:26
• 2022-01-31Watts says that time counts from the first PCBs; he starts thinking about the next product on finishing one, and began considering Mojo 2 as soon as Mojo was finished. Darko.Audio 50:47
• 2022-01-31Watts says Mojo 2's UHD DSP is his own core, balanced outputs would degrade transparency, a USB-C charging port would not fit, and musicality comes first. Head-Fi, Jan 2022
• 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
• 2022-01-31Watts says Mojo 2 auto-offs after 10 minutes without inputs, stays in desktop mode while powered, trails Hugo 2, uses a digital DC servo, and improved 16FS-to-2048FS filtering. Head-Fi, Jan 2022
• 2022-01-31Watts says the UHD DSP runs at 705/768 kHz on the output of WTA1 or the DSD filter, and there is no WTA2. Head-Fi, Jan 2022
• 2022-01-31Watts says fully charged Mojo 2 enters desktop mode with the battery disconnected, unlike Hugo 2, so he improved PSU rejection and made the charger a low-impedance source. Head-Fi, Jan 2022
• 2022-01-31Watts says DSP core speed is irrelevant and taps count; Mojo 2 has four fifths of Hugo 2's tap length, no WTA2, and taps are only part of sound quality. 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
• 2022-02-01Watts says Mojo 2's DSP core passes bit-perfect data when EQ and crossfeed are off, it still uses the 15T FPGA, and lists Hugo 2's advantages over it. Head-Fi, Feb 2022
• 2022-02-01Watts says it reproduces -301dB but its -320dB noise floor at 6kHz prevents proving 0.001dB accuracy; the 4-element noise shaper is 250dB versus DAVE's 350dB. Head-Fi, Feb 2022
• 2022-02-02Watts explains Mojo 2's FPGA charger, 0.5A to 2A charging, 99.3dB SPL with the HEKV2, why coupling caps soften bass, why Mojo lacked a DC servo, and USB-C for Poly. Head-Fi, Feb 2022
• 2022-02-03Watts says Mojo 2's battery has 9% more capacity, its peak EQ filters use Q 0.5, and the EQ targets headphone bass problems and overall balance, not sharp treble resonances. Head-Fi, Feb 2022
• 2022-02-04Watts describes Mojo 2's desktop mode, 11-day trickle top-up, operation with a failed battery, and his aims for the EQ settings and transparent DSP core. Head-Fi, Feb 2022
• 2022-02-05Watts explains Mojo 2's USB-ground ferrites, when external filters might help (optical is best), how crossfeed mimics loudspeaker listening, and reduced 2G buzz. Head-Fi, Feb 2022
• 2022-02-06Watts says he considered an M Scaler mode for DAVE/TT2, TT2's 7W beats DAVE plus power amp, NFM-free treble sounds natural, and he has not started a DAVE replacement. Head-Fi, Feb 2022
• 2022-02-07Watts says he mainly uses DCA Aeon 2 Closed, and Mojo 2 uses the original Mojo DSD filter because 98% of FPGA resources were used, though its HF filter helps. Head-Fi, Feb 2022
• 2022-02-08Watts says 14 years consulting for semiconductor firms taught right-first-time design; finished designs are frozen so a 2015 DAVE sounds like a 2022 one, and he avoids sales-driven upgrades. Head-Fi, Feb 2022
• 2022-02-08Watts says the UHD DSP has 3 overload bits so EQ never clips internally, but boosts require lower volume: Mojo 2 can clip at white, or violet with +6 dB. Head-Fi, Feb 2022
• 2022-02-11Watts says his high-end M Scaler uses a Choral (DAVE) chassis and is not 4M taps, algorithm outweighs taps, and gives SINAD of 125dB (Mojo 2) and 127dB (TT2). Head-Fi, Feb 2022
• 2022-02-12Watts says Mojo and Mojo 2 measure identically, but Mojo's warmth came from coupling-capacitor distortion removed by the DC servo; a bass shelf boost restores it. Head-Fi, Feb 2022
• 2022-02-12Watts says SMPS tones do not cause NFM unlike random RF, recalls switching regulators beating linear in Hugo, and prefers power banks for isolation from RF ground currents. Head-Fi, Feb 2022
• 2022-02-14Watts says the HF filter mainly removes noise and distortion in 96/192k recordings, helps 44.1k slightly, and Mojo 2's UHD DSP lets it stay on with flat response. Head-Fi, Feb 2022
• 2022-02-14Watts says 64-bit floating-point EQ creates noise floor modulation and small-signal errors; Mojo 2 uses 104-bit noise-shaped fixed point; his DACs need no warm-up or break-in. Head-Fi, Feb 2022
• 2022-02-15Watts relays Chord's view that Mojo 2 USB noise reports look like a USB sync loss, advises exclusive mode and closing apps first, then emailing Chord support. Head-Fi, Feb 2022
• 2022-02-18Watts says a poster's per-filter numbers match his plots, notes that summing magnitudes ignores phase, and plans to check on his APx555 with Mojo 2. needs context Head-Fi, Feb 2022
• 2022-02-19Watts says an adaptor costs a little transparency through extra contacts, and Mojo 2 shuts down after 10 minutes without SPDIF lock or USB VBUS, by design. Head-Fi, Feb 2022
• 2022-02-21Watts says DSD is filtered and converted to 705.6 kHz PCM before the UHD DSP, so EQ, crossfeed and volume work identically. Head-Fi, Feb 2022
• 2022-03-10Watts says no Mojo 2 EQ setting replicates Mojo, whose warmth and bass coloration came from one coupling capacitor, not frequency response; a 125Hz boost adds warmth only. Head-Fi, Mar 2022
• 2022-03-16Watts describes recording an amateur orchestra with a Blumlein ribbon mic into a Focusrite ADC, compares playback with live, and blames lost depth, transients and timbre on the ADC. Head-Fi, Mar 2022
• 2022-03-19Watts says WTA was tuned mostly by listening, down to ten parts per million on the windowing function, and Mojo 2 has over 500 times a chip DAC's processing. MFG Audio Reviews 22:49
• 2022-03-19Watts says the theory applies from Mojo 2 to DAVE, and Mojo 2 needed more FPGA power since the original Mojo used a third of its FPGA, being power limited. MFG Audio Reviews 24:26
• 2022-03-19Watts says Mojo's case can dissipate about 1.8 watts; he saved about 300 milliwatts in the analog section, spent 250 more on the FPGA, and battery capacity rose 9%. MFG Audio Reviews 25:11
• 2022-03-19Watts says the result is lower temperature, more processing and longer battery life, and he now uses 98% of the FPGA's capacity. needs context MFG Audio Reviews 25:54
• 2022-03-19Watts says Chord wanted Mojo's coupling capacitor replaced by a DC servo as on Hugo 2, but the capacitor gave Mojo its warm, soft sound, so warmth needed restoring. MFG Audio Reviews 26:14
• 2022-03-19Watts says adjusting the sound meant EQ, but EQ on a 64-bit PC degrades transparency and IIR EQ filters had immense problems he could fix, and he built the UHD DSP. MFG Audio Reviews 26:59
• 2022-03-19Watts says Chord insisted only on the same size and Poly compatibility; Mojo 2 is DC coupled via a digital DC servo, and the original Mojo had 38,000 taps. MFG Audio Reviews 27:42
• 2022-03-19Watts says Mojo 2 has 40,960 taps, an updated WTA architecture and an improved noise shaper, and an improved 4 element pulse array; he was worried about a distortion bump near 70 to 200 kHz. MFG Audio Reviews 28:30
• 2022-03-19Watts says lower out-of-band noise makes Mojo 2 slightly warmer, existing DSP is not transparent, and proposes a test: each EQ band up 1 dB, volume down 1 dB. MFG Audio Reviews 29:18
• 2022-03-19Watts says DSP EQ uses biquad filters whose small bass coefficients and truncation errors grow through feedback, so very small signals are lost and phase shifted. MFG Audio Reviews 33:55
• 2022-03-19Watts says 64-bit float sounds brighter, and transparent EQ DSP must reproduce -301 dB perfectly in amplitude and within a thousandth of a degree in phase, without floating point. MFG Audio Reviews 35:31
• 2022-03-19Watts says he calculated the DSP needed 104 bits, but tests showed it failed -301 dB in phase though not amplitude, so he added noise shaping. MFG Audio Reviews 36:12
• 2022-03-19Watts explains that a noise shaper feeds each error back to correct the next sample rather than discarding it, which requires oversampling, so the DSP runs at 705 kHz. MFG Audio Reviews 36:44
• 2022-03-19Watts says noise shaping cannot work at 44.1 kHz, bass coefficients are tiny, and noise shaping each node separately fixed the 104-bit design's phase failure so it passed. MFG Audio Reviews 37:33
• 2022-03-19Watts says the digital simulation is the real output, and shows the DSP reproducing -301 dB within thousandths of a dB and thousandths of a degree. MFG Audio Reviews 38:18
• 2022-03-19Watts says the test used +9 dB at 20 Hz, -9 dB at 20 kHz and a 6 kHz sine; volume now spans -108 to +18 dB for sensitive IEMs. MFG Audio Reviews 39:06
• 2022-03-19Watts says an indicator shows whether the volume is in the high or low range, and begins on the bass tone controls. MFG Audio Reviews 39:52
• 2022-03-19Watts describes the tone controls: 20 Hz bass peak, bass shelf below 125 Hz, 3 kHz treble shelf, 20 kHz peak, each 9 dB either way in 1 dB steps. MFG Audio Reviews 40:04
• 2022-03-19Watts says the broad tone controls can fix headphone bass but not a 6 kHz resonance, and that crossfeed was added; with Hugo 2 he cannot listen without crossfeed. MFG Audio Reviews 40:53
• 2022-03-19Watts says crossfeed on Hugo 1 gave no out-of-head sense, but on Hugo 2 it improved depth, and Mojo 2 is similar thanks to better small signal accuracy. MFG Audio Reviews 41:42
• 2022-03-19Watts says crossfeed improves depth, a permanently on DSP HF filter flat to 20 kHz helps all sources, especially 96 and 192 kHz, and UHD DSP loses no depth. MFG Audio Reviews 42:27
• 2022-03-19Watts says the EQ can fix headphone bass or sibilance at 3 kHz, skips the menus, will post the slides on Head-Fi, and notes plus and minus together mutes. MFG Audio Reviews 43:15
• 2022-03-19Watts says he spent much time making the controls intuitive, reports suggest they are easy to use, and there is a lockdown setting; he moves on to measurements. MFG Audio Reviews 44:00
• 2022-03-19Watts gives measurements: 125 dB dynamic range and distortion much as on Mojo, but 118 dB stereo separation from better supply isolation, so the battery is isolated when running permanently. MFG Audio Reviews 44:22
• 2022-03-19Watts shows no noise floor modulation (same -177 dB floor with signal on or off), low distortion, and a perfectly reproduced 16-bit small signal with left and right superimposed. MFG Audio Reviews 45:02
• 2022-03-19Watts says the ringing is expected, the 16-bit result is state of the art with only TT2 and DAVE slightly better, and Mojo sold in large numbers after 2015. MFG Audio Reviews 45:45
• 2022-03-19Watts sums up that Mojo 2 builds on Mojo with state-of-the-art transparency and musicality, meaning emotional involvement, plus a good DSP, and invites questions. MFG Audio Reviews 46:30
• 2022-03-19Watts says four buttons at the same depth forced cylinders rather than balls, non-rotating is more elegant and less likely to rattle, and button design is not his domain. MFG Audio Reviews 58:17
• 2022-03-21Watts warns about placebo in listening tests and explains the HF filter reduces noise floor modulation while WTA2 (16FS to 256FS) improves transient timing, neither changing in-band response. Head-Fi, Mar 2022
• 2022-03-26Watts says desktop mode isolates the battery, and that recursive IIR EQ needs 104 bits plus noise shaping while FIR filters need fewer bits to reproduce -301 dB accurately. Head-Fi, Mar 2022
• 2022-03-29Watts says Mojo needed topping up after weeks on the shelf, but Mojo 2's standby current is an order of magnitude lower, taking 7 months to go flat. Head-Fi, Mar 2022
• 2022-04-04Watts says high current and low output impedance let two headphones share the output, Mojo 2 uses 98% of the FPGA versus 33%, and he avoids trivial updates. Head-Fi, Apr 2022
• 2022-04-10Watts says the desktop DAC headphone relay protects on plug-in via a delay, but unplugging can short before relays act; Mojo 2 and Hugo 2 outputs are always active. Head-Fi, Apr 2022
• 2022-04-26Watts says the original Mojo was limited to about 1.8 watts, so he used only a third of its FPGA; for Mojo 2 he reworked the analog section's efficiency. Audio Force 3:29
• 2022-04-26Watts says he saved 300 or 400 milliwatts and batteries improved about 9 percent, so Mojo 2 uses 98% of the FPGA instead of 33% at lower total power. Audio Force 4:16
• 2022-04-26Watts says he designed an FPGA-driven charging circuit for Mojo 2 so it can be charged while listening without getting hot, bringing Hugo 2 technology into it. Audio Force 4:58
• 2022-04-26Watts says he and John Franks wanted to add crossfeed, which he always uses with headphones, and remove the single coupling capacitor after the pulse array, which adds warmth. Audio Force 5:22
• 2022-04-26Watts says the original Mojo was voiced warm for bright headphones, so neutral Mojo 2 needed EQ; his test: raise a PC EQ 1 dB, lower volume 1 dB. Audio Force 6:09
• 2022-04-26Watts says a flat but active PC EQ still sounds flatter in soundstage, less detailed, brighter and worse in timbre, so he set out to design a lossless DSP. needs context Audio Force 7:01
• 2022-04-26Watts says Mojo 2's EQ DSP uses 104 bits and noise-shaped internals, making it far more transparent, and that forum users report EQ changes do not degrade sound. Audio Force 7:49
• 2022-04-26Watts says typical 64 or 128 tap filters make transients constantly shift early or late; Mojo 2's WTA uses 40 DSP cores per channel and over 40,000 taps. Audio Force 10:44
• 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 his goal is live unamplified sound, MQA can be decoded in the source so Mojo 2 loses nothing, and MQA is fundamentally the wrong way. Audio Force 13:28
• 2022-04-26Watts says many original Mojos ran 24/7 as fixed-system DACs, so for Mojo 2 he made the battery fully isolated when the charger is connected. Audio Force 14:06
• 2022-04-26Watts says isolating the battery in desktop use required separate regulation in Mojo 2's analog section, since the original Mojo's analog stage fed directly from the battery. Audio Force 14:51
• 2022-04-26Watts says with added power supply rejection and regulation, the new unit used 24/7 on the charger isolates the battery without trickle charging, preserving battery life. Audio Force 15:33
• 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
• 2022-04-27Watts says he designed his own for the ADCs, video leaves headroom to go above white without clipping, and Hugo 2 and Mojo 2 give the Stealth ample volume. Head-Fi, Apr 2022
• 2022-05-01Watts says Mojo 2's USB decoder has its own regulation and RF filters, he is independent of Chord, and two headphone sockets were kept for reliability and sharing. Head-Fi, May 2022
• 2022-05-14Watts cannot discuss future products but designed the UHD DSP with future uses in mind; he needs no EQ on his DCA Stealth or B&W 803 D3. Head-Fi, May 2022
• 2022-05-18Watts quotes his Mojo 2 presentation: for 2 V output, set both volume LEDs to indigo. Head-Fi, May 2022
• 2022-05-18Watts says Mojo 2 has no separate output stage: the discrete output stage sits inside a single amplifier with one feedback path, so nothing is bypassed. Head-Fi, May 2022
• 2022-05-28Watts attributes a 1 kHz measurement artifact to APx555 ground currents over USB, discusses ground loops and optical as reference, and gives settings for noise floor modulation tests. Head-Fi, May 2022
• 2022-06-01Watts says Mojo 2 in desktop mode runs from the charger via its regulator with the battery disconnected, topping the battery up every 11 days. Head-Fi, Jun 2022
• 2022-06-22Watts says any charger usually makes little difference; test by disconnecting it, and if it matters, power Mojo 2 from a power bank unplugged from mains. Head-Fi, Jun 2022
• 2022-06-28Watts says every Chord desktop DAC since DAVE has galvanic isolation with the USB decoder source-side, and battery-powered Mojo 2 or Hugo 2 with headphones won't need it. Head-Fi, Jun 2022
• 2022-07-06Watts says Chord is investigating the Mojo 2 USB noise issue but cannot replicate it; exclusive mode makes it rare, and the noise is the maximum at that volume setting. Head-Fi, Jul 2022
• 2022-09-04Watts has never heard a whining sound from his DACs and suggests turning on after Windows boots, or getting the Mojo 2 replaced. Head-Fi, Sep 2022
• 2022-09-14Watts recounts RF filters warming the sound since the 1980s, and says a null result with Mojo 2's flat UHD DSP HF filter shows the effect is noise floor modulation. Head-Fi, Sep 2022
• 2022-09-18Watts says Mojo 2 has done really well; Chord can build five or ten thousand pieces in a month and they are gone. The Source AV 28:08
• 2022-09-18Watts says they sell out worldwide; he thinks in South Korea 500 units sold within an hour of launch. The Source AV 28:19
• 2022-09-18Watts says Mojo 2 is a big step up from the original Mojo. The Source AV 28:39
• 2022-09-18Watts says the big thing they have not touched on is that the key feature of Mojo 2 was the DSP. The Source AV 33:08
• 2022-09-18Watts says the Mojo 2 project started 5 years ago, and John Franks wanted to get rid of the coupling capacitor. The Source AV 33:15
• 2022-09-18Watts says removing the coupling capacitor makes bass tighter, more extended and deeper, but the capacitor gave Mojo 1 its warmth. The Source AV 33:30
• 2022-09-18Watts says a transparent DSP lets users make Mojo 2 warmer and softer or sharper and brighter with EQ; it took a year or two and a custom 104-bit core. The Source AV 34:07
• 2022-09-18Watts says on Mojo he has built the filter into it. The Source AV 38:06
• 2022-11-21Watts agrees with a poster's figure, saying he calculated 48 hours with Mojo 2 on and somewhat more with it off. needs context Head-Fi, Nov 2022
• 2022-11-25Watts says Mojo 2 has the digital DC servo introduced with DAVE in 2015 plus DC protection on its relays, calls the reported fault unique, and wants the unit. Head-Fi, Nov 2022
• 2022-12-01Watts says Mojo 2 has no analog gain change; he raised volume steps from 96 to 128 for sensitive IEMs, with the menu button showing high or low range. Head-Fi, Dec 2022
• 2022-12-19Watts says no one in the Mojo 2 speculation thread predicted its big change, the UHD DSP EQ. Head-Fi, Dec 2022
• 2023-01-21Watts says his Blumlein recordings show lateral imaging is already perfect with crossfeed on Mojo 2 and Stealth; depth, attack and timbre need improving, digital sounding too soft. Head-Fi, Jan 2023
• 2023-01-26Watts says matching the microphone's image width needs maximum crossfeed (blue on Hugo 2/Mojo 2), which he generally uses because older recordings were hard-panned. Head-Fi, Jan 2023
• 2023-02-04Watts says Chord DACs from Mojo 2 to Dave have no measurable noise floor modulation, all others do, and that any amount, however small, is subjectively important. Dusty Audio 33:58
• 2023-02-20Watts says Mojo 2's 4-element pulse array runs its noise shaper slower for low distortion, so noise rises around 100k and falls at 400k from analog filtering. Head-Fi, Feb 2023
• 2023-03-03Watts doubts an unspecified product would sell in volume and says it would cannibalize Mojo 2 and Qutest, since Mojo 2 only works commercially in large volumes. needs context Head-Fi, Mar 2023
• 2023-03-12Watts quotes the Mojo 2 factory reset procedure that clears EQ and crossfeed, and says he left out an EQ on/off option to keep operation simple. Head-Fi, Mar 2023
• 2023-03-17Watts advises buying the original-rate release since WTA cannot undo non-integer SRC, and says the 2A charger advice is about holding 5 V at Mojo 2's port. 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
• 2023-03-30Watts gives Stealth SPL at 0dBFS (98.3 dB Hugo/Mojo, 100.0 Dave, 103.4 TT2 headphone, 109.1 balanced), warns against long listening above 80dB, and suggests volume settings. Head-Fi, Mar 2023
• 2023-03-30Watts explains SPDIF locking and the lock flag, which Mojo 2 uses to switch data sources and disable auto shutdown, regardless of whether the data is silent. Head-Fi, Mar 2023
• 2023-04-03Watts says transparent EQ needs -301 dB performance in amplitude and phase; after a couple of years' work, the DSP core in this unit is 104 bits. Amplify Audio 8:57
• 2023-04-03Watts says the DSP runs at 768 kHz, or 705 kHz for 44.1 material, and is noise-shaped, so the EQ is transparent. Amplify Audio 9:29
• 2023-04-03Watts says improving Mojo meant adding crossfeed, essential for headphones, and moving toward Hugo 2's sound by going DC coupled, dropping the coupling capacitor that gave Mojo its warmth. Amplify Audio 10:23
• 2023-05-30Watts says Mojo 2's bass EQ range covers IEMs rolling off at 125 Hz, he sets +3 or +4 dB shelf on his Stealth, and a shutdown pop is harmless. Head-Fi, May 2023
• 2023-05-31Watts says the battery's own protection cutting out before Mojo 2's FPGA shuts down is no cause for worry. Head-Fi, May 2023
• 2023-06-21Watts breaks down background noise sources and Mojo 2's trade-offs (2.2 nV/rtHz, 5.2 V RMS), warns attenuators harm sound, and cites 4.4 mm connector cost. Head-Fi, Jun 2023
• 2023-07-15Watts says all M scalers will work with all current DACs, including Mojo 2 and Hugo 2 via dual data, that scaler benefits need long-term listening, and urges forum civility. Head-Fi, Jul 2023
• 2023-07-28Watts agrees Mojo 2 drives the Stealths perfectly and says he runs the 125 Hz shelf at +3 dB with other EQs at 0. Head-Fi, Jul 2023
• 2023-07-28Watts rejects full parametric EQ and conventional EQ, says Mojo 2's 104-bit EQ core was his idea, and describes its modest FPGA cost. Head-Fi, Jul 2023
• 2023-07-30Watts says 64-bit floating point creates noise floor modulation, unlike his noise-shaped fixed point in Mojo 2's UHD DSP, and suggests Class H for efficient amplification. Head-Fi, Jul 2023
• 2023-08-06Watts says Mojo 2 can sound peppy or rich, warm and leisurely depending on the music, headphones and EQ settings. Head-Fi, Aug 2023
• 2023-08-07Watts says Class H cost depends on the PSU, all analog electronics suffer noise floor modulation, and Mojo 2's battery charger uses a simple Class H type design. 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
• 2023-09-20Watts describes tuning WTA variables to about 100ppm with dedicated test tracks, notes Hugo 2's warm settings remove WTA2, and says Mojo 2's UHD DSP adds warmth without timing loss. Head-Fi, Sep 2023
• 2023-09-29Watts reports from SoCal CanJam and a visit to Atlantic Studios West, which bought Dave and Mojo 2s, where recording engineers were interviewed about Chord gear. Head-Fi, Sep 2023
• 2023-10-01Watts says Mojo 2 launched about 18 months ago and that COVID brought huge parts problems, with FPGA prices soaring before coming down again. The Source AV 2:00
• 2023-10-01Watts says products are priced from performance and bill of materials cost, and that when designing Mojo he had to stay within a budget. The Source AV 2:49
• 2023-10-01Watts says Mojo was hard work and that the Mojos are the exception, since normally he picks a performance target first. The Source AV 3:00
• 2023-10-01Watts says, seriously, that a Mojo put in a huge fancy copper box with the same performance and its contents hidden would sell at $100,000. The Source AV 7:24
• 2023-10-01On the EQ, Watts says he tests with a -301 dB signal, far below audibility, because the brain can perceive it if the quality of that signal is slightly wrong. The Source AV 8:39
• 2023-10-01Watts says Mojo 2 has his own custom 104-bit noise-shaped DSP core running at 705/768 kHz, whose noise shaper keeps impulse-response tails that fall below the noise floor. The Source AV 11:22
• 2023-10-01Watts agrees and says the DSP core also performs the volume control and crossfeed. The Source AV 13:05
• 2023-10-01Watts says Tom interviewed Atlantic Studios' four recording engineers, who bought DAVEs and Mojo 2s about a year ago, and he joined after arriving early for jet lag. The Source AV 17:19
• 2023-10-01Watts says the Atlantic engineers used Mojo 2 on that session and always use Mojo 2 for portability. The Source AV 20:37
• 2023-10-01Watts says they also use Mojo 2 in the main studios when they do not have access to DAVE. The Source AV 20:43
• 2023-10-01Watts says the engineers prefer Mojo 2 to any other DAC for its soundstage depth and refined transparency, hearing faults and subtle adjustments immediately, which improved their efficiency. The Source AV 20:48
• 2023-10-01Watts says that as he improved products such as Hugo, Mojo 2, Hugo 2 and DAVE, headphones started to sound different. The Source AV 21:37
• 2023-10-01Watts says he would not have spent the three or four months developing and evaluating the DSP core unless he knew it could be used in other products. The Source AV 37:34
• 2023-10-01Watts says Chord could not afford to put a Pentaconn connector on the Mojo. The Source AV 38:59
• 2023-10-01Watts says heat sinking is a major issue: fanless Mojo 2 can dissipate about 2.5 W at 38 C, his preferred maximum, through convection and infrared radiation. The Source AV 45:19
• 2023-11-13Watts says Mojo's first batch had USB connectors breaking off, fixed with through-hole connectors and tighter machining used on Mojo 2, rated for 10,000 insertions. Head-Fi, Nov 2023
• 2023-11-20Watts says 64-bit floating point creates audible noise floor modulation, and Mojo 2's EQ runs at 16FS with noise-shaped nodes in 104 bits. Head-Fi, Nov 2023
• 2024-01-07Watts says the 10-minute warm-up he heard on flights was most likely his ears adjusting to cabin pressure or the headphones, not the DACs, and that Mojo 2 exposes headphones with poor LF distortion. Head-Fi, Jan 2024
• 2024-01-08Watts says some headphones are said to sound better with external amps although Mojo 2 and Hugo 2 drive them easily to ear-splitting levels. Head-Fi, Jan 2024
• 2024-01-14Watts says Chord's 3 V standard dates from 1990s passive pre-amps, Qutest added 1/2/3 V options, and a Mojo 2 line-level output was dropped to keep controls simple. Head-Fi, Jan 2024
• 2024-02-19Watts says Mojo 2 desktop mode disconnects the battery, trickle charges it every 11 days, charges below full capacity for longevity, and adds a regulation stage with RF filters. Head-Fi, Feb 2024
• 2024-02-19Watts says Mojo 2's desktop mode is new; Hugo 2 relies on its batteries for dynamic currents, and waiting for magenta rather than blue gives longer battery life. Head-Fi, Feb 2024
• 2024-02-29Watts says optical is the reference input for Mojo 2, while USB from a quiet or battery-powered source such as a phone sounds identical, given bit-perfect data. Head-Fi, Feb 2024
• 2024-03-02Watts says that so long as the volume is not white it cannot clip, even with the maximum digital input of 0dBFS. Head-Fi, Mar 2024
• 2024-03-07Watts explains Mojo 2's bass shelf and 20Hz peak settings were chosen to compensate a first-order bass roll-off at 125Hz found in many Japanese IEMs, keeping EQ simple. Head-Fi, Mar 2024
• 2024-03-20Watts says Mojo 2 takes 16 seconds after power-on to null its DC trim, and ferrite-core inductors are nasty because inductance and phase vary with signal amplitude. MFG Audio Reviews 52:45
• 2024-03-30Watts says the 24-hour charge applies to Hugo 2, not Mojo 2, whose charge time depends on initial state, with the final 95% to 100% trickle taking hours. Head-Fi, Mar 2024
• 2024-05-16Watts says it can be used with Mojo 2 or any Chord DAC, because they all accept dual BNC. ConvinceMeAudio 11:42
• 2024-06-10Watts says Mojo 2 has an HF filter permanently engaged, which sounds much better, and its 20 to 20k bandwidth is flat with EQ off. Head-Fi, Jun 2024
• 2024-06-10Watts explains earlier DACs had switchable HF filters because of a 20kHz drop, while Mojo 2's new DSP core allows a fast roll-off with no in-band change, so no switch is needed. Head-Fi, Jun 2024
• 2024-06-11Watts says the Mojo 2 HF filter's IIR phase change is linear and inaudible, unlike interpolation timing errors, and a listening test against an ADC-project FIR filter confirmed this. Head-Fi, Jun 2024
• 2024-07-19Watts says flashing red lights indicate a thermal trip from a short on the outputs, likely an amplifier shorting its inputs when powered down, so remove the cable. Head-Fi, Jul 2024
• 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
• 2024-09-25Watts says a cold Hugo 2 showed no warm-up change, so in-flight brightness was headphones or ears, and Mojo 2 saves settings to FLASH only after menu mode times out. Head-Fi, Sep 2024
• 2024-11-11Watts advises sending bit-perfect data in its mastered format, calls DSD technically flawed, and says he uses Hugo 2 with Stealth, so Mojo 2 will drive Stealth fine. Head-Fi, Nov 2024
• 2024-11-13Watts says Hugo 2's charger chip may or may not work without a battery, unlike Mojo 2, and that Hugo 2 battery failures are extremely rare. Head-Fi, Nov 2024
• 2024-12-11Watts says both indicators must be white for clipping, assuming no boost EQ; with +3dB EQ, go three steps down to avoid clipping at 0dBFS. needs context Head-Fi, Dec 2024
• 2025-02-17Watts says Mojo 2's transparent EQ uses a 104-bit DSP core at 768 kHz with every IIR node aggressively noise shaped, recirculating rather than discarding truncated bits. audio-2G 14:59
• 2025-02-17Watts says modern DSPs miss that accuracy but his Mojo 2 cores and a similar Quartet core do, so EQ keeps depth intact; he tests with alternating half-dB bands. audio-2G 18:39
• 2025-03-23Watts says pre-Mojo 2 HF filters were second order with about -0.9dB at 20kHz, while Mojo 2's UHD DSP allows an aggressive filter with no drop, reducing noise floor modulation. Head-Fi, Mar 2025
• 2025-03-26Watts explains causal versus symmetric acausal filters, says interpolation pre-ringing at 22kHz is not an issue but EQ should be causal, and lists his CanJam schedule. 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
• 2025-09-14Watts says many studios use DAVEs, Mojo 2s and Hugos, recording engineers keep asking when the A to D converter will come out, and his son understands their needs. The Source AV 3:15
• 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 many DAVE sales, and Quartet sales once people have heard it, came from people who started with a $650 Mojo and heard something new. ecoustics 1:18:21
• 2026-03-17Watts says many start with Mojo 2 and end with DAVE, and understanding why things change the sound lets him spend resources on what improves it as budgets rise. ecoustics 1:19:05
• 2026-03-17Watts says many designers just tweak, but for Mojo 2 he knew beforehand what he wanted: the best within budget, closer to Hugo 2, with set benefits over Mojo. ecoustics 1:19:59
• 2026-03-17Watts says he guessed Mojo 2 would have around two-thirds the performance of a Hugo 2 compared to Mojo, and listening tests matched, with no surprises. ecoustics 1:20:45
• 2026-03-17Watts says he listened to a Mojo through Quartet last week and it transforms a Mojo as much as it does DAVE. ecoustics 1:25:47
• 2026-03-17Watts says he is not recommending buying a Quartet and a Mojo 2. ecoustics 1:26:03
• 2026-03-17Watts says contact him by Head-Fi PM; next year begins an active-loudspeaker project, and since Mojo 2's EQ is transparent, replacing passive crossovers should greatly improve speakers. ecoustics 1:28:33
• 2026-03-24Watts says Mojo 2 sounded remarkably good with Quartet as its source, showing the correct source fundamentally improves even something as humble as Mojo 2. Audio Force 28:54
• 2026-03-24Watts says Mojo 2 is inexpensive and limited by its source, then introduces Quartet's analog input, a pulse array A-to-D converter, prompted by recording engineers praising DAVE. Audio Force 29:11
• 2026-03-24Watts says the older Mojo 2 needed adapters, and every metal-to-metal interface damages sound, so the dedicated connector improves detail and soundstage; USB-C charging is the other major benefit. Audio Force 32:33
• 2026-03-24Watts says volume and EQ settings are now remembered separately for the 4.4 mm and 3.5 mm outputs, for owners using Mojo 2 at high volume on a desktop and with IEMs on the move. Audio Force 33:44
• 2026-03-24Watts says the USB-C charging options required an FPGA change, but all of the audio parts are identical to the original Mojo and unchanged. Audio Force 34:28
• 2026-03-24Watts says he always uses Mojo 2's lossless EQ, especially flying since things sound different at 8,000 feet, and unlike normal EQ it does not damage sound quality. Audio Force 36:34
• 2026-05-03Watts says the built-in 4.4 mm connector sounds better than adapters, since any metal-to-metal interface hurts detail and depth, and adds a programmable USB-C charging option. Audio Force 21:35
• 2026-05-03Watts says the programmable USB-C charging feature can be turned off when using a mobile phone over USB-C so the battery is not depleted, and turned back on when needed. Audio Force 22:22
• 2026-10-02Watts says all his DACs except Mojo 2 add a WTA stage from 16FS (705/768 kHz) to 256FS (about 12 MHz), then filters up to 104 MHz. HiFi Buys 1:15:13
• 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
• 2026-10-02Watts says the industry is dysfunctional: despite his talking about transient timing since DAC64 in 1999, and Mojo and Mojo 2 selling well over one hundred thousand devices, nobody discusses it. HiFi Buys 2:27:55
• 2026-10-02Watts says his Mojo 2 target was two-thirds of the way from Mojo (0%) to Hugo 2 (100%) in sound quality, which he can predict on paper. HiFi Buys 2:29:40
• 2026-10-02Watts says Mojo 2's digital EQ drew on his work on small-signal phase shift, since EQ changes phase, and making it transparent was much harder than expected. HiFi Buys 2:30:22
• 2026-10-02Watts says getting the EQ's measurements right was hard; the EQ was really built for his IP library for future pro audio, where subjectively lossless EQ will be profoundly important. HiFi Buys 2:31:10
• 2026-10-02Watts says Mojo 2 needed many board iterations, and the first prototype hit his two-thirds target, a gap clear enough to protect Hugo 2 sales. HiFi Buys 2:31:58
• 2026-10-02Watts says had Mojo 2 turned out better than expected he would have kept it, even if Chord complained about selling fewer Hugos. HiFi Buys 2:32:57
• 2026-10-11Watts says Hugo 2's desktop mode lowers battery voltage for safe constant charging; Mojo 2 isolates the charged battery, so RF filtering on its power input was improved. Distorsiuni Interioare 40:27
• 2026-10-11Watts says the battery versus charger difference is very low, depending on system RF sensitivity; if heard, use a power bank into Mojo 2; forums report no losses. Distorsiuni Interioare 42:28
• 2026-10-11Watts says connecting the charger audibly caused problems on Mojo 1, which does not happen with Mojo 2. Distorsiuni Interioare 43:23
• 2026-10-14Watts says ESS chips have half a dozen filters and at most a few hundred taps, versus 4 million on Quartet and, he thinks, about 44 thousand on Mojo 2. Part-Time Audiophile 33:10
• 2026-10-14Watts says talk of negative feedback is not entirely accurate; all his DACs except Mojo 2 use second order noise shapers giving 120 dB of feedback at 20 kHz. Part-Time Audiophile 1:00:59
• 2026-10-17Watts says his Mojo 2 4.4 mm connector listening tests used Quartet and it transformed Mojo 2; it works but would not be a sensible pairing. article, Oct 2026

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