The short version: A diamond the size of a grain of sand rides a wiggling groove, and a magnet and a coil turn that wiggle into a tiny signal that a phono preamp lifts and corrects. This section covers that chain, plus the settings and storage habits behind most skips, hiss, lopsided stereo and worn records. Two lab studies of record wear disagree about what happens to the groove, and both are given here.
How does one groove carry two channels?#
A stereo LP has one groove with two walls, and the two recording directions sit at 90 degrees to each other and at 45 degrees to the record surface.119 Put a signal on one channel alone and only one wall is modulated; the other stays smooth.119 That is the 45/45 system, which Westrex showed to engineers in Hollywood on August 26, 1957, and which, Ralph W. Wight wrote in 1975, the Record Industry Association of America adopted "as the American standard" on December 27, 1957.15 A rival vertical-lateral system had backing from Sugden in the UK and Telefunken in Germany, and Decca was experimenting with it too.15 One reason 45/45 won: both channels were cut the same way, so they used the same equalization and carried the same rumble, where a vertical system would have put more rumble in one channel.15 The history section tells how stereo records reached the public.
In practice the stylus does not read two walls separately. A 1958 magazine explainer called that idea a misconception, since "it is impossible for the stylus to follow different contours on both walls of the groove at the same time."120 The tip moves in a mix of sideways (lateral) and up-and-down (vertical) motion, and real music traces angled, circular or elliptical paths.120
Which phase gives which motion is where the 1958 sources part ways. The Westrex engineers wrote that in-phase signals cut a vertical groove and out-of-phase signals a lateral one.119 Norman Crowhurst wrote the opposite: in-phase gives lateral motion, out-of-phase gives vertical.120 The split comes from how each defines channel phase. The common modern explanation, that a mono signal moves the stylus purely sideways, follows Crowhurst's convention.
The wall assignment, at least, is not in dispute: the International Association of Sound and Audiovisual Archives (IASA) states in its transfer guidelines that the inner wall carries the left channel and the outer wall the right.121 The standard that defines channel phasing, IEC 60098, lists "channel phasing" as a clause, but its public preview does not include the wording.122
The design was also built to stay compatible: Westrex wrote that an ordinary lateral pickup with decent vertical give would still play back the lateral part of both channels, and each 45/45 channel came out about 3 dB below a mono lateral record with the same playing time.119
What is the difference between moving magnet and moving coil?#
Both types make a signal by moving a magnet relative to a coil. In a moving magnet (MM) cartridge the magnet rides on the cantilever, the tiny arm that carries the stylus, and the coils stay put; in a moving coil (MC) cartridge it is the other way round.123 MC designs use fewer turns or thinner wire to keep the moving parts light, which is why their output is lower.123
| Moving magnet (MM) | Moving coil (MC) | |
|---|---|---|
| What moves | magnet on the cantilever | coils on the cantilever |
| Typical output | 4-8 mV, many around 4 mV | usually under 2.5 mV |
| Example (maker claim) | Ortofon 2M Blue, 5.5 mV | Ortofon Quintet Blue, 0.5 mV |
| Phono gain suggested | about 40 dB | 60 dB or more |
Sources: Crutchfield for typical outputs and gain;124 What Hi-Fi? for the Ortofon examples.123
On price, What Hi-Fi? listed a Goldring E3 MM at GBP 89 / USD 189 and the Quintet Blue MC at GBP 389 / USD 569 in 2023 (reported retail), and advised staying with MM if the turntable cost under GBP 1,000 / USD 1,250.123
The two types are also serviced differently. Ortofon says the styli in its MC cartridges "are non-replaceable," so it runs an exchange scheme that buys back a worn or damaged MC at 25% of current list price against a new one of the same grade or better, while its MM cartridges are serviced by fitting a new stylus (policy as published in 2026).125 That is one maker's policy, not an industry rule.
Which stylus shape should I care about?#
The shape of the diamond decides how much of the groove wall it touches. Audio-Technica's 2025 catalogue rates its own styli by shape, and those hours are the maker's figures, not a law of nature.126
| Shape | What it is | Where you find it | Audio-Technica life (2025, maker) |
|---|---|---|---|
| Conical | most common, basic shape | entry-level | about 300-500 h |
| Elliptical | more elongated, smaller contact area | mid-range to high end | about 300 h |
| Shibata | very narrow, flat contact surface | high end | about 800 h |
| MicroLine | narrow contact surface | high end | about 1,000 h |
| Special Line Contact | very fine, extended contact area | high end | about 800 h |
Descriptions: K&B Audio;127 hours: Audio-Technica.126
For a sense of scale, Ortofon specifies the elliptical tip on its 2M Red with radii of 8 and 18 µm.128 A 1968 RCA study used a 0.2 by 0.7 mil elliptical and a 0.7 mil conical.129
How long does a stylus last?#
It depends on whose number you read. Audio-Technica rates its elliptical at about 300 hours,126 while Ortofon says the elliptical 2M Red can reach up to 1,000 hours with proper care "without degradation of performance."128 A retailer guide puts conical at about 500 hours and credits Audio-Technica, which is the top of A-T's own range.127 A turntable brand's blog says styli usually last about 1,000 hours.130 The fair reading: check the hours your cartridge's maker publishes, and treat any single universal figure with suspicion.
How much should the stylus weigh on the record?#
Tracking force is the downward weight on the stylus, set with the tonearm's counterweight. Set it to the cartridge maker's figure: too light and the record skips, too heavy and it can damage the groove.130 The Ortofon 2M Red, for example, has a range of 1.6-2.0 g with 1.8 g recommended.128 Forces used to be much heavier. The 1958 Westrex pickup tracked at 6 g,119 and in 1968 about 5 g was common on everyday players.129
There is an engineering reason light tracking mistracks. Westrex wrote that the stylus's static deflection from tracking force has to be large compared with the biggest vertical modulation in the groove, or the tip leaves the groove.119
There is no single right number across makers. Audio-Technica says the recommended force "varies from cartridge to cartridge," and its 2015 setup guide gives 2 g for its AT95E and 3.5 g for its ATP-2XN.131
What does anti-skate actually do?#
A pivoted, offset tonearm has a quirk. Friction drags the stylus along the groove, but the arm can only resist force along its own length, and the leftover pulls it toward the center of the record.132 That is skating force. Louder passages and a dirty stylus or record mean more friction and more skating, and a 12-inch arm skates less than a shorter one.132 Left alone, the stylus leans on the inner groove wall, which can cause mistracking and uneven wear on both stylus and record.132 Anti-skate is an outward bias that cancels it.
How much is in dispute. Kogen measured skating at about 20% of tracking force for an elliptical and 15-18% for a conical in 1967; Boisclair estimated about 10%; Stereophile suggests starting near 10% and adjusting by ear.132 Then the advice conflicts. House of Marley says to set the anti-skate dial to match the tracking force, and to back it off if the stylus skips outward.130 Stereophile calls anti-skate equal to tracking force "way too high."132 Both can be right, because the dial is not a force gauge: Korf measured actual anti-skate at roughly 5-30% of the number on the dial.132 The Library of Congress says to check tracking and anti-skate at least monthly, or whenever mistracking shows up.133
Do I need a phono preamp?#
Yes, built in or separate. A cartridge's signal is far below line level, and the phono preamp (or phono stage) does two jobs: it adds gain, and it applies the inverse RIAA curve.124 A PHONO/LINE switch on a turntable turns its built-in stage on or off.124
The RIAA curve exists because of cutting. The lathe boosts treble and cuts bass so the groove's swing stays more even across the range, and playback does the reverse to get back to flat.57 The curve is defined by three time constants, 3180, 318 and 75 µs, with corners near 50 Hz, 500 Hz and 2,122 Hz.57 A true constant-amplitude cut would need about 60 dB more gain at 20 kHz than at 20 Hz; RIAA settles for about 40 dB.57 IEC 98 was first published in 1964, and a 1976 amendment added a 7950 µs infrasonic roll-off, -3.0 dB at 20 Hz, which drew criticism.57 Nearly all vinyl follows RIAA, apart from some pre-1954 records.124
The RIAA Technical Committee approved the curve on January 29, 1954, and the document circulated that June, according to Kohji Matsubayashi's History of Phono EQ Curves, which also notes that the original 1954 text has not been located.13
Does direct drive or belt drive matter?#
In direct drive the platter sits on the motor; belt drive turns it through a belt; idler drive uses a rubber wheel.134 For a listener at home, makers sell good decks of every type. For a DJ, direct drive changed everything: high torque, near-instant start, steady speed and a platter you can push around or spin backward without harm.135 The DJ section picks up from there.
Two sources disagree on the first direct-drive deck. IEEE Spectrum says the Technics SP10, designed by Shuichi Obata, came out in 1969.135 Technics' own history page says the SP-10 launched in 1970 as "the world's first direct drive turntable."136
What do wow, flutter and rumble mean on a spec sheet?#
Wow is slow pitch wobble and flutter is fast pitch wobble; both are given as a percentage, and lower is better.134 Rumble is noise from the deck's own moving parts that the stylus picks up, and makers often leave it off.134 As a reference point, Panasonic lists the SL-1200MK7 at 0.025% wow and flutter (weighted RMS), 0.7 seconds to reach 33 1/3 rpm and 0.18 N·m of starting torque, and gives no rumble figure.137
How should I clean records?#
Start with hands. The Library of Congress says to handle discs by the edge and label, with clean, dry hands, and to let discs from cool storage reach room temperature before playing.138 It also says to brush the stylus with a dense bristle brush before each side.133
For the records, the methods line up like this, with views differing on which is best:
| Method | What the sources say |
|---|---|
| Sink wash, mild detergent | common; an archival-leaning source suggests lukewarm mild detergent, a distilled-water rinse and air-drying, keeping the label dry, and says there seems to be "no systematic evidence" against dish soap139 |
| Brush bath (Spin-Clean type) | removes dust, softens fingerprints and mold140 |
| Vacuum machine | removes large and small dirt, ideally with a final pure-water rinse140 |
| Ultrasonic | the only method AnalogPlanet's author says "effectively removes in-groove contaminants"; 40 kHz for larger dirt, 120 kHz for in-groove dirt, and below about 30 kHz cavitation may damage PVC140 |
| Wood-glue peel | no serious evidence, and the glue is likely acidic, about pH 3139 |
The same archival source notes that no published microscope study of ultrasonic cleaning on records exists, even though some archives endorse it.139
Why does static matter?#
Fresh PVC records come out of the mold with a strong negative charge, which pulls in dust.139 A 1980 microscope study in Audio rated static a minor cause of crackle next to groove fracture; its main harm is attracting grit that scours the groove.141 Remedies in the literature include carbon-fiber brushes, conductive mats, polonium-210 neutralizer bars and anti-static compounds, while the same archival source says detergent sprays give only "very temporary relief."139 The Library of Congress recommends high-density polyethylene inner sleeves.138
How should I store records?#
Upright, on edge, with immovable dividers every 4-6 inches, and without mixing sizes.138 Records are heavy: the Library of Congress puts grooved discs at more than 35 pounds per shelf-foot.138 At home it suggests room temperature or below and about 35-40% relative humidity, away from attics and basements; for permanent storage, 46-50°F and 30-40% RH.138 The Library's own advice has shifted: its older 2002 "Nutshell" sheet gave 45-50% RH for long-term storage.133
What warps a record?#
Heat. It relaxes the stresses molded into the PVC, and a hot car is the classic case; one archival summary says keep records below 70°F (21°C) and out of light, and that flattening with heat and pressure is "never certain."139 A 2026 press piece puts the point where warping is all but guaranteed at about 140°F (60°C), and cites, via Vorby, a 2021 Discogs survey (reported, not seen here) in which 22% of collectors named warps as their most common damage.142 Short dividers and mixed diameters on a shelf may contribute to warping too.133
Why does my record keep skipping?#
A skip is the stylus losing the groove. A turntable brand's checklist covers most causes: a deck that is not level, tracking force too light, anti-skate wrong (skipping outward means too much), a dirty or worn stylus, a warp, worn grooves (white streaks, skips in the same spot), and dust.130 A record weight can flatten a warp but is not a permanent fix.130 Sometimes the record arrived that way: a 1980 microscope study found small holes and surface flaws even on an unplayed audiophile pressing.141
Does playing a record wear it out?#
Yes, and the two best-known studies disagree about how. In RCA's 1968 electron-microscope study by Woodward and colleagues, a 0.2 by 0.7 mil elliptical at 1.5 g left visible "plastic-flow of the groove wall" after one play, building over 10 and 50 plays; a 0.7 mil conical at 5 g nearly wiped out 20 kHz detail after 50 plays; the same conical at 1.5 g showed essentially no wear after 50.129 The study put a critical tracking weight somewhere between 1.5 g and 5 g, and its authors still preferred the elliptical, since the conical's first-play distortion was more than twice as high.129
In 1980, Walter E. Davies played records at 1 g with anti-skate set, at an estimated 30,000-69,000 psi of contact pressure, and found mostly small chip-like fractures rather than large permanent deformation.141 After 50 plays one record was "almost unlistenable," critical listeners heard loss after 2-10 plays, and the vinyl's formulation strongly affected wear.141 So Woodward saw flow and Davies saw fracture, in different decades with different vinyl and pickups. The overlap is practical: lighter, correctly set tracking and a clean stylus and record go easier on the groove.