# Vinyl presets: where the numbers come from

Researched 2026-10-18. Every value below was read from the page listed (not
from search snippets). **MEAS** = measured (by whom); **SPEC** = the
manufacturer's figure; **(chart)** = read from a published graph (about ±1 dB).
Hi-Fi News and Stereophile pages were read in a browser (they block automated
fetching). Preset values live in `js/vinyl-presets.js`.

Reference levels differ between sources: Stereo Review / Hirsch-Houck Labs
quote output at 3.54 cm/s; Hi-Fi News, Shure, Ortofon and Audio-Technica at
5 cm/s; LowBeats at "DIN 0 dB" (about 1.6 × the 5 cm/s output).

## Cartridges

| Preset | Used in the preset | Basis | Source |
| --- | --- | --- | --- |
| Ortofon 2M Red | Response (chart): +1.75 dB at 20 Hz, flat 50 Hz–5 kHz, +1 dB at 10 kHz, +2.75 dB at 20 kHz. Crosstalk (chart, worse curve): −31 dB at 1 kHz, −22 dB at 10 kHz. Resonance 9 Hz in an 11.2 g arm → compliance 16.8 µm/mN (derived). Mass 7.4 g. | MEAS LowBeats | https://www.lowbeats.de/test-ortofon-2m-red-ein-top-einsteigersystem/ ; specs https://ortofon.com/products/2m-red |
| Audio-Technica VM540ML | Response: LowBeats (chart) +0.5–1 dB 20–100 Hz, +3.5–4 dB at 10–15 kHz, +1–2 dB at 20 kHz; HomeTheaterHifi (STR-100) +4.3/+2.6 dB at 12–14 kHz, −0.5/−1.5 dB at 20 kHz → averaged. Separation: 21–26 dB at 1 kHz, 17–18 dB at 10 kHz. 2nd harmonic 0.9% at 10 kHz, 5 cm/s (HTHF) → line-contact tracing coefficient. Resonance 7.6 Hz (LowBeats), 7.5 Hz Q≈3 (HTHF) → compliance 24.9 µm/mN (derived). | MEAS LowBeats, HTHF | https://www.lowbeats.de/test-audio-technica-vm540ml/ ; https://hometheaterhifi.com/reviews/vinyl/turntable-accessories/audio-technica-vm540ml-phono-cartridge-review/ |
| Shure V15 Type IV | Within ±0.8 dB 40 Hz–20 kHz (HHL, STR-100, 240 pF); L +¾/−½, R +1¼/−½ dB 20 Hz–20 kHz (CBS). Separation ~29 dB at 1 kHz, 17–18 dB at 10 kHz. Resonance 11 Hz in an SME 3009 (stabilizer on). Compliance not published: 13 µm/mN derived assuming a 10 g arm. Mass 6.4 g. | MEAS Hirsch-Houck (Stereo Review 5/1978), CBS (High Fidelity 6/1978) | https://www.worldradiohistory.com/Archive-All-Audio/Archive-HiFI-Stereo/70s/HiFi-Stereo-Review-1978-05.pdf ; https://www.worldradiohistory.com/Archive-High-Fidelity/70s/High-Fidelity-1978-06.pdf |
| Denon DL-103 | Measured as the DL-A110 (a DL-103 in a headshell): L +0.9/−4.5 dB (−2 dB at 10 kHz, −5 dB at 20 kHz), R ±0.9 dB, 20 Hz–20 kHz → channels averaged. Separation 33 dB at 1 kHz, 25 dB at 20 kHz (10 kHz interpolated 28). Compliance ~8 cu vertical / 13 lateral. Mass 8.5 g. Conical 16.5 µm (SPEC). | MEAS Hi-Fi News | https://www.hifinews.com/content/denon-dl-a110-cartridge-lab-report |
| Ortofon SPU | Proxy: Thorens SPU 124 (Ortofon-built SPU): −1 dB at 5 kHz, −4 dB at 10 kHz, −8 dB at 20 kHz; ~25 dB separation; ~8 cu compliance. Mass 28 g, 0.2 mV (SPEC, SPU Classic). | MEAS Hi-Fi News (proxy) | https://www.hifinews.com/content/thorens-td-124-dd-turntable-thorens-spu-124 ; https://ortofon.com/products/spu-classic-ge-mkii |
| Lyra Kleos SL | Response −1.8 to +2.8 / −1.9 to +4.1 dB over 20 Hz–20 kHz (shape assumed: rising top octave). Separation 40 dB at 1 kHz, 25 dB at 20 kHz. Compliance 25/28 cu. Mass 8.8 g. | MEAS Hi-Fi News | https://www.hifinews.com/content/lyra-kleos-sl-cartridge-lab-report |
| Hana Umami Blue | Separation 32.5 dB (L) / 34.8 dB (R) and THD 0.26% / 0.25% at 1 kHz, measured on the Blue (test conditions not stated). Response is a proxy from Hi-Fi News's Umami Red lab report (same Microline nude stylus and boron cantilever): flat to 8–9 kHz, then +1.6 dB (L) / +4 dB (R) at 18 kHz on lateral cuts → averaged +2.8 dB; Red separation 31 dB at 1 kHz / 20 dB at 20 kHz → Blue 10 kHz interpolated to 26 dB. Compliance 10 cu at 100 Hz, estimated 17 cu at 10 Hz by Hana (Red measured 9/10 cu by HFN). Mass 10.8 g, 0.4 mV, 8 Ω (SPEC). The Absolute Sound describes the Blue as the most neutral Hana, so the Red's treble lift may overstate it. | MEAS The Absolute Sound (Blue); MEAS Hi-Fi News (Umami Red, proxy); SPEC Hana | https://www.theabsolutesound.com/articles/hana-umami-blue-phono-cartridge/ ; https://www.hifinews.com/content/hana-umami-red-cartridge-lab-report ; https://www.analogplanet.com/content/hana-umami-blue-moving-coil-cartridge ; https://www.spacehifi.com.au/hana/hana-umami-blue-mc-cartridge |
| Shure M44-7 | 20 Hz–20 kHz, 20 dB separation at 1 kHz, spherical 18 µm, compliance 20 × 10⁻⁶ cm/dyne, 7 g. No measurement found. | SPEC | https://content-files.shure.com/KnowledgeBaseFiles/27A331_9-65_M44-5_M44-7_M44C_M44G.pdf |
| Grado Prestige Gold | 10 Hz–55 kHz, average 25 dB separation, compliance 20 µm/mN, 6 g. Gramophone review (quoted by Grado) notes a slight dip around 5 kHz. | SPEC | https://gradolabs.com/products/gold4 ; https://gradolabs.com/pages/prestige-cartridge-reviews |
| Denon DL-160 (high-output MC) | Response 1–20 kHz +2/−0 dB (chart: about 0 dB at 5 kHz, +0.5–1 at 10 kHz, L +1.5–2 / R 0 at 20 kHz → +0.9); below 1 kHz not measured (the test record was played unequalized), assumed flat. Separation 25 dB at 1 kHz, 21 dB at 10 and 20 kHz. Output 2.99 mV (rated 1.6). Resonance 8–10 Hz in a 17 g arm → compliance about 14 µm/mN at 10 Hz (derived; Denon: 10 × 10⁻⁶ cm/dyne at 100 Hz). Tracking 60 µm at 315 Hz (DIN 45-549) at the recommended force; mistracked the +12 dB IM band. 4.8 g, 1.3–1.9 g (SPEC). | MEAS Stereo Review (Julian Hirsch, January 1988); SPEC directories | https://www.worldradiohistory.com/Archive-All-Audio/Archive-HiFI-Stereo/80s/HiFI-Stereo-Review-1988-01.pdf ; https://www.worldradiohistory.com/Archive-All-Audio/Archive-Audio/80s/Audio-1983-10.pdf |
| Sonotone 9TA (ceramic) | Response (chart, left channel, through Sonotone's adapters into a magnetic input, 3 g): −3 dB at 30–50 Hz, −2 at 100 Hz, −2 at 3 kHz, −1 at 5 kHz, +3 at 9 kHz, 0 at 10 kHz, −5 at 14 kHz, +5 at 20 kHz. Separation: better than 25 dB 1–6 kHz, gone above 12 kHz (HSR 1961; about 10–15 dB at 10 kHz, chart) and about 20–27 dB at 1 kHz, 0–3 dB at 10 kHz (HF 1962) → 25 / 7 dB. Compliance 5.5 × 10⁻⁶ cm/dyne (SPEC, frequency not stated); 0.7 mil diamond; 2–4 g. Mass not published: the Sonotone 8TA's 2.8 g (SPEC). No tracking-ability figure; tracked the Cook 60 and Fairchild 101 records at 3.5 g. No measurement exists of a ceramic straight into a cheap player's high-impedance input. | MEAS United States Testing Co. (High Fidelity, November 1962), Hirsch-Houck (HiFi/Stereo Review, October 1961) | https://www.worldradiohistory.com/Archive-All-Audio/Archive-High-Fidelity/60s/High-Fidelity-1962-Nov.pdf ; https://www.worldradiohistory.com/Archive-All-Audio/Archive-HiFI-Stereo/60s/HiFi-Stereo-Review-1961-10.pdf |

**Tracing distortion by stylus shape** (2nd harmonic at 8 kHz, 5 cm/s, 5-inch
radius): spherical 6.4%, biradial (elliptical) 4.0%, hyperelliptical 2.5%
(Shure 1978 technical seminar,
https://content-files.shure.com/KnowledgeBaseFiles/high-fidelity-phonograph-cartridge-technical-seminar-faq.pdf).
Since 2026-10-23 the distortion is made in the groove: the music is turned
into groove velocity (RIAA pre-emphasis), gains τ·v·dv, and the error goes
back through playback EQ. Coefficients (`TRACE`, per 5 cm/s and per kHz) are
calibrated in the simulation so the output 2nd harmonic at 8 kHz, 5 cm/s
matches Shure (spherical 0.01486, elliptical 0.00929, hyperelliptical
0.0058), and at 10 kHz HomeTheaterHifi's line-contact VM540ML, 0.9% (line
0.00164). At 1 kHz that gives elliptical 0.69%, spherical 1.1%. Earlier the
term was computed on the music before pre-emphasis, which understated treble
tracing distortion about 4 times and overstated bass-against-treble
intermodulation.

**Where the simple form breaks.** Corrington (RCA Review, June 1949,
https://worldradiohistory.com/ARCHIVE-RCA/RCA-Review/RCA-Review-1949-Jun.pdf,
Eqs. 26–33) gives the spherical-tip 2nd harmonic as ¼·R·A²… whose leading term
is H2 = π·r·f·v/V² = x/2, with x = r·acceleration/V² (the tip radius over the
groove's tightest bend); his series isn't valid past x = 1, where the tip
rides only the crests. Traced exactly as a rigid sphere (our computation, which
matches his series at x = 1), the 2nd harmonic levels off toward 50%:
H2 ≈ 0.5·tanh(x). The model applies that, with x from the peak of the groove
acceleration over the last 2 ms (our choice). Measured extremes agree: Walton
(JAES 14(2), 1966, http://freudhoefer.de/File_Share/Walton.pdf, Figs. 1b and
13, read from graphs) found about 20% total distortion at 8 kHz, 10 cm/s RMS,
5-inch diameter for a 0.6 mil spherical tip, and above 32% at 12 cm/s peak; the
model gives a conical tip near the label 27–31% at 8 kHz, 5–12 cm/s. At Shure's
test conditions the cap changes nothing measurable (6.3% for 6.4%).

Check against Shure's intermodulation test (1 kHz + 1.5 kHz at 25 cm/s peak,
same paper): Shure measured spherical 2.4%, biradial 1.8%, hyperelliptical
1.4%; the model gives about 5.2%, 3.3% and 2.0% (difference products at 500 Hz
and 2.5 kHz). Shure doesn't state which products its figure counts, and one
coefficient can't match both tests, so the model's vinyl intermodulation may
read up to about twice the real value; the order of the stylus shapes is right.

The digital RIAA filters use the bilinear transform for the bass corners and
matched poles and zeros for the 75 µs corner (playback within 0.4 dB of the
analog curve at 8 kHz and 1.6 dB at 16 kHz; plain bilinear was 4.3 dB low at
16 kHz).

**Tracking ability** (`track`: the largest 300 Hz lateral groove swing tracked
cleanly, µm peak, at the force given; Hi-Fi News's 300 Hz bands are referenced
to 11.2 µm, so +12 dB = 45 µm, +14 = 56, +15 = 63, +18 = 89):

| Cartridge | Figure | Basis |
| --- | --- | --- |
| Ortofon 2M Red | 70 µm at 315 Hz, 1.8 g | SPEC Ortofon (https://ortofon.com/products/2m-red) |
| Audio-Technica VM540ML | none published; typical 70 µm, 2.0 g | typical |
| Shure V15 Type IV | 80 µm at 1 g (70 at 0.75 g, 100 at 1.25 g), German Hi-Fi Institute record | MEAS Stereo Review, May 1978 |
| Denon DL-103 | 75 µm at 2.5 g | MEAS Hi-Fi News (DL-A110) |
| Ortofon SPU | fails at +14 dB, about 56 µm, at 3.0 g | MEAS Hi-Fi News (SPU 124); Ortofon specifies 60 µm for the Classic GE MkII |
| Lyra Kleos SL | clears +18 dB (89 µm) at 1.75 g | MEAS Hi-Fi News |
| Hana Umami Blue | 70 µm at 2 g | SPEC Hana (the Umami Red measured 70–75 µm, Hi-Fi News) |
| Shure M44-7 | none (designed before trackability measurement, Shure 1976 catalog); typical 70 µm | typical |
| Grado Prestige Gold | none; typical 70 µm. Stereophile found its tracking "less accomplished than that of other budget cartridges" | typical |
| Denon DL-160 | 60 µm at 315 Hz | MEAS Stereo Review, January 1988 |
| Sonotone 9TA | none; typical 70 µm | typical |

Above about 500 Hz the limit is a groove speed: Shure measured the V15 IV at
1 g tracking 29, 42, 47 and 37 cm/s peak at 400 Hz, 1, 2 and 10 kHz (E. R. Happ,
Audio, June 1978, https://www.worldradiohistory.com/Archive-All-Audio/Archive-Audio/70s/Audio-1978-06.pdf).
The model gives every cartridge the V15 IV's ratio of that 42 cm/s average to
its 300 Hz figure (our choice). Checked against the test records: the SPU starts
to fail at +14 dB, the DL-103 holds +15 dB, the Kleos holds +18 dB, and the V15 IV
holds 30 cm/s at 10.8 kHz (Shure TTR-103 bands 15–30 cm/s, tracked cleanly in
Stereo Review's test). On our recordings at the site's playback level, only the
bass-heavy hip-hop clip briefly exceeds the weakest trackers' limits.

**Output** (`output`: mV at 1 kHz, 5 cm/s; sets the phono stage's hiss and
headroom relative to the music; added 2026-10-23):

| Cartridge | Output | Basis |
| --- | --- | --- |
| Ortofon 2M Red | 5.5 mV | SPEC Ortofon |
| Audio-Technica VM540ML | 4.0 mV | SPEC https://www.audio-technica.com/en-us/vm540ml (LowBeats measured about 3.3 mV, velocity not stated) |
| Shure V15 Type IV | 3.85 mV | MEAS Stereo Review, May 1978 ("3.85 millivolts at a stylus velocity of 3.54 cm/sec", RMS, the same tone as 5 cm/s peak), https://www.worldradiohistory.com/Archive-All-Audio/Archive-HiFI-Stereo/70s/HiFi-Stereo-Review-1978-05.pdf; Shure specifies 4.0 mV |
| Denon DL-103 | 0.55 mV | MEAS Hi-Fi News (DL-A110), https://www.hifinews.com/content/denon-dl-a110-cartridge-lab-report; Denon specifies 0.3 mV |
| Ortofon SPU | 0.2 mV | SPEC Ortofon (SPU Classic) |
| Lyra Kleos SL | 0.326 mV | MEAS Hi-Fi News, https://www.hifinews.com/content/lyra-kleos-sl-cartridge-lab-report (rated 0.25 mV) |
| Hana Umami Blue | 0.4 mV | SPEC Hana |
| Shure M44-7 | 9.5 mV | SPEC Shure 1976 catalog, https://www.worldradiohistory.com/Archive-Company-Publications/Shure/1976_shure_Phonograph.pdf (the 1965 data sheet says 11 mV) |
| Grado Prestige Gold | 4 mV | SPEC Grado (Gold4, "4 mV @ 5 CMV (45 degrees)"), https://gradolabs.com/products/gold4 |
| Denon DL-160 | 2.99 mV | MEAS Stereo Review, January 1988 |
| Sonotone 9TA | 10 mV | SPEC |

Grado and Lyra quote 5 cm/s along one channel's 45° axis; a 5 cm/s lateral cut
gives about 3 dB less on each channel. Others don't say; we take every figure
as given.

**Inner-groove treble loss** (`grooveLossDb` in `js/vinyl.js`): Miller's model as
restated by CBS Laboratories (1962), via http://pspatialaudio.com/wavelength_loss.htm:
response 1 − (f/fc)², fc = 6.65×10⁻² · D·N · (E/(R·F))^⅓. Spherical tips use
their radius (M44-7 18 µm, DL-103 16.5 µm, 9TA 17.8 µm); other shapes use a
radius fitted to Hi-Fi World's measured inner-minus-outer loss at 20 kHz and 2 g
(https://www.hi-fiworld.co.uk/index.php/vinyl-lp/25-cartridges/914-audio-technica-vm95-cartridges.html?showall=1
and the DL-304 and 2M Bronze reviews): elliptical about 3 dB → 4.29 µm;
line-contact and Shibata about 1.1 dB → 1.17 µm; hyperelliptical counted with
the long-contact shapes. The model breaks down near fc, so the loss stops at
20 dB. Result at 10 kHz near the label: conical about −2 dB (Hi-Fi World: VM95C
−2 dB at 10 kHz), elliptical −0.6 dB, line contact −0.3 dB.

## Turntables

| Preset | Used in the preset | Basis | Source |
| --- | --- | --- | --- |
| Technics SL-1200GR2 | Peak wow 0.01%, flutter 0.02%; rumble −73.8 dB DIN-B (groove); arm 8–9 g; speed −0.004%. Flutter rate: motor cogging 26.6 Hz (calculated). | MEAS Hi-Fi News | https://www.hifinews.com/content/technics-sl-1200gr2-lab-report ; https://www.audiocognoscenti.com/blog/study-of-cogging-torque-in-technics-sl-1200-turntables |
| Linn LP12 (Majik/Krane) | Peak wow 0.02%, flutter 0.04%; wow at ±2 Hz, flutter sidebands at ±12 and ±50 Hz; rumble −70.1 dB DIN-B; arm 10 g. | MEAS Hi-Fi News; Stereophile corroborates ±50 Hz motor sidebands | https://www.hifinews.com/content/linn-majik-lp12krane-turntable-package-lab-report ; https://www.stereophile.com/content/linn-sondek-lp12-turntable-lingo-power-supply-measurements |
| Rega Planar 3 | Proxy Planar 2: peak wow 0.02%, flutter 0.03%; rumble −68.1 dB; RB220 arm 11 g. Flutter rate assumed 10 Hz. (Stereophile measured a Planar 3 running 0.31% fast; speed error isn't modeled.) | MEAS Hi-Fi News (proxy) | https://www.hifinews.com/content/rega-planar-2-turntable-lab-report ; https://www.stereophile.com/content/gramophone-dreams-14-rega-planar-3-page-2 |
| Pro-Ject Debut Carbon EVO | Peak wow 0.02%, flutter 0.03% with a ±41 Hz component; rumble −69.1 dB; arm 7 g. | MEAS Hi-Fi News | https://www.hifinews.com/content/pro-ject-debut-carbon-evo-turntable-lab-report |
| Garrard 301 restored (SME 301 Advanced) | Factory restoration of a 1950s idler-drive 301 in SME's heavy plinth (23 kg with arm), SME V-12 arm. Peak wow 0.03% (±2.2 Hz component, 1:4 idler/inner-platter ratio), peak flutter 0.04%; rumble −70.9 dB silent groove / −65.9 dB through bearing (DIN-B); hum and noise −57.0 dB unweighted re 5 cm/s; speed +0.25% fast until adjusted, then +0.04%. Flutter rate and V-12 effective mass not published (25 Hz and 12 g assumed). Hum is not modeled. | MEAS Hi-Fi News | https://www.hifinews.com/content/garrard-301-advanced-lab-report |
| Garrard Zero 100 (changer) | Wow 0.1%, flutter 0.025% (weighting not stated); rumble −55.5 dB CBS RRLL weighted (−32 dB unweighted). Arm mass not published (15 g assumed); flutter rate assumed 8 Hz. | MEAS Hirsch-Houck (Stereo Review 7/1971) | https://www.worldradiohistory.com/hd2/IDX-Audio/Archive-Stereo-Review-IDX/IDX/70s/HiFi-Stereo-Review-1971-07-OCR-Page-0034.pdf |

Rumble weightings differ (DIN-B, CBS RRLL, IEC 98A) and aren't directly
comparable. The model treats each figure as DIN-B-like and generates rumble
about 10 dB louder unweighted, concentrated below 40 Hz and at the arm
resonance.

## Records and general vinyl facts

| Fact | Value | Source |
| --- | --- | --- |
| Surface noise, silent groove | −45 to −47 dB re 1 kHz at 5 cm/s peak, wideband unweighted (Shure); RIAA allowance −55 dB re 7 cm/s (≈ −52 dB re 5 cm/s) | Shure seminar; https://www.analogplanet.com/images/vinyl-dynamic-range.pdf |
| Noise after repeated play | +3.7 dB after 50 plays (3 kHz band, untreated record) | https://patents.google.com/patent/US4096079A/en |
| Groove speed at 33⅓ | ~51 cm/s outer, ~20–21 cm/s inner → inner grooves 2.5 × tracing distortion | https://en.wikipedia.org/wiki/Phonograph_record ; https://pspatialaudio.com/max_velo.htm |
| Warps | Typical 4 Hz at 0.076 mm; 70% below 5 Hz, 95% below 8 Hz; good arm/cartridge resonance 10 Hz, Q 3 | Holman, Audio 7/1977: https://www.worldradiohistory.com/Archive-All-Audio/Archive-Audio/70s/Audio-1977-07.pdf |
| Largest dish warp | ~0.64 mm at the lowest frequencies (OCR text; verify) | https://patents.google.com/patent/CA1180663A/en |
| Mono bass (elliptical EQ) | Side channel high-passed at 75/150/300 Hz; historical Neumann units 6 dB/octave | https://www.ka-electronics.com/kaelectronics/Elliptic_EQ/Elliptic_EQ.htm ; https://www.soundonsound.com/sound-advice/q-should-master-my-material-vinyl |
| Program levels | Peaks at least 15 dB above 5 cm/s (Atkinson); model sets average music 6 dB below 5 cm/s | https://www.stereophile.com/content/linn-sondek-lp12-turntable-lingo-power-supply-measurements |

## Not measured anywhere we found (typical values used)

- Click and crackle rates and levels, and worn-record noise.
- Shure M44-7 and Grado: no lab measurements (specifications only).
- Inductance of moving-coil cartridges; V15 compliance; Rega Planar 3 wow and rumble; changer arm mass; Garrard 301 flutter rate and SME V-12 arm mass.
- No lab measurements found for a restored Garrard 401 (only owner app readings, about 0.11% wow and flutter).
- Speed error (pitch offset) is not modeled.

## Phono stages

Stereophile pages were read in a browser. RIAA errors are read from the graphs
(about ±0.1 dB), both channels averaged and set to 0 dB at 1 kHz.

| Stage | Used in the preset | Source |
| --- | --- | --- |
| Pro-Ject Phono Box RS2 | RIAA within ±0.15 dB. MM: S/N 83.5 dB A-weighted re 5 mV (any gain); overload 32 dB at 1 kHz, 20 dB at 20 kHz (lowest gain, 1% THD+N). MC at highest gain (70 dB, which a low-output cartridge needs): S/N 62 dB A re 500 µV; overload 22.5 dB at 1 kHz, 20 dB at 20 kHz. Subsonic filter (−3 dB at 22 Hz) left off | MEAS Stereophile, https://www.stereophile.com/content/pro-ject-phono-box-rs2-phono-preamplifier-measurements |
| Fosi Audio BOX X1 | MM only, 35 dB gain. RIAA: −4.0 dB at 20 Hz, −1.5 at 100 Hz, +0.9 at 5 kHz, +1.2 at 20 kHz (5.2 dB end to end). Overload: 1% THD at about 55 mV (graph), 20.8 dB above 5 mV, one frequency only, assumed the same at 20 kHz. No noise figure: SINAD 74 dB at about 5 mV (10 Hz–22.4 kHz) bounds the hiss; +2.6 dB for A-weighting white noise gives 76.6 dB (our arithmetic) | MEAS Audio Science Review, https://www.audiosciencereview.com/forum/index.php?threads/fosi-box-x1-ultracheap-phono-stage-review.62976/ |
| EMT 128 | MC only (transformer input, 12–30 Ω cartridges), "−6" gain setting (62.5 dB). RIAA flat to ±0.2 dB from 30 Hz to 10 kHz, −1.2 dB at 20 kHz. S/N 76.3 dB A re 500 µV. Overload 8.3 dB at 1 kHz, 3.5 dB at 20 kHz re 500 µV. 2nd harmonic 0.3% at 500 µV (not modeled) | MEAS Stereophile, https://www.stereophile.com/content/emt-128-phono-preamplifier-measurements |

The hiss is modeled as white at the output: the RS2's A-weighted and
22 Hz–22 kHz figures sit 3.8 dB apart, where white noise gives 2.5 dB (the
EMT's are 12 dB apart, more low-frequency noise, which A-weighting discounts).
Cartridges under 1.5 mV use the moving-coil input, others the moving-magnet
input (our choice); only stages with that input are offered for a cartridge.

## Cutting limit (treble velocity)

Real records can't carry unlimited treble: the cutter head's acceleration is
limited. Sources (2026-10-23):

- Neumann BSB 74 acceleration limiter (SAL 74 / SX 74 system, 1974): "a current
  limit of 1.4 Amps in the band above 4kHz thereby limiting all accelerations to
  8150m/s² (830g)", quoted from its manual at http://pspatialaudio.com/max_accel.htm
  (secondary source; the manual itself not seen).
- Jim Lesurf, Hi-Fi News 2007, "On The Record"
  (http://www.audiomisc.co.uk/HFN/LP2/OnTheRecord.html): measured LPs peak at
  about +17–19 dB re 5 cm/s, with treble peaks within about 1,000 g (≈21 cm/s at
  7 kHz, ≈15 at 10 kHz, a few cm/s above 14 kHz on a ZZ Top single).
- Kogen, "Trackability", Audio, November 1966: about 25 cm/s on good stereo
  records from 800 to 2,500 Hz; one record needed 1,500 g at 14 kHz.
- Shure's survey (Happ, Audio, May–June 1978, Fig. 1): hottest measured points
  about 50 cm/s at 7–17 kHz, which implies 3,000–5,000 g and conflicts with the
  sources above; not used.
- Hi-Fi News "Making Headroom" boxouts (Paul Miller): +18 dB re 5 cm/s taken as
  the fiercest groove modulation, without a frequency.

Model (`CUT` in js/vinyl.js, `cutLimit` in js/vinyl-processor.js): the music as
groove velocity; the band above 4 kHz (2nd-order high-pass) is turned down when
its acceleration passes 830 g, instant attack, 50 ms release (our choice). It
acts on what is cut, so tracing, mistracking and phono overload see it, and it
stays in the linear reference. On our clips it cuts the 16 kHz octave's peak
velocity from 51 to 22 cm/s on the brightest (Night Owl, about −3.6 dB of top
treble on average) and leaves classical recordings untouched.