Here's some food for thought, self-plagerised from my own posts on this topic, which are fairly scattered to the wind, it pulls them together:
Here's an attempt at an explanation, and an audio simulation that seems pretty plausible, IMO. And perhaps explains all manner of vinyl surface noise effects and events......
If groove-stylus friction randomly changes due to natural vinyl material variation, say, in vinyl surface grain, instantaneous friction would have random flicker noise, (pink). It being by far the most common in nature.
ie friction would vary randomly to an extent, with a noise-time variation like this :
Marked up, is a hypothetical red line, above which a stylus might move (micro-mistrack) due to downforce being inadequate to hold position. Red line position depends on groove modulation forces, and cartridge/stylus specifics.
Cartridge noise output would be just due to the fraction above the line, where the stylus moves. Which might comprise this, for example :
One can see, it looks like random pop/crackle, the correct form for the noise we observe here.
You can hear how remarkably close to the observed noise sound it is ! What I'm suggesting is the effect of loud hf sounds, like Miles' trumpet, or the Tom Petty intro, is to lower the red line. Also this simulation sounds remarkably
like surface noise in general. It's spooky.
So I'm pretty enthusiastic about this explanation, can't see a contradiction in fact.
Also, it perhaps opens the door to exploring and explaining the nature of surface noise in general, why and how it varies. For example, how wetting significantly influences surface noise, or why surface noise decreases toward inner grooves, how new vinyl pressing have variable surface noise, why worn styli show more surface noise. This is, of course, enormously interesting.
I think 'micro-mistracking' would always have both some lateral, and vertical motion content, it being a slide up one groove wall, in principle. So not much pure in-phase or out-of-phase L/R content, and a bit of a mixed bag i think. Seems to accord with some of my recordings. Also with the general view that L/R surface noise is not coherent.
The direction stylus would move when downforce isn't enough to hold it (in 'micro' mistracking), would depend upon the momentum and direction it already had, and direction of other forces in play. So it's not easy to analyse, i think, but motion would always have at least some
vertical component to it.
Even if friction flicker noise is a 'sometimes' factor in surface noise, it is unlikely to be the only factor. I also like the 'base clearance' theory as to why there can be variance between styli as to surface noise performance.
I thought about how friction flicker noise might apply to silent grooves, and general surface noise. At first, I couldn't see how any upforce could be generated. Then realised there is c 20 deg VTA, and c 25 deg lateral tracking angle (applied to 45 deg wall), through which tonearm drag is applied. Tonearm drag would have flicker varation, of course, it being groove-stylus friction derived. So perhaps it's possible.
I'm curious whether, rather than surface level variation (pits and peaks), variation in vinyl material composition contributes to variation in friction, and so that is a mechanism for normal surface ticks, pops and crackle ? Even in silent grooves.
Just that a bad pressing, eg many from the 70s in the great vinyl famine, seems to show a very similar crackle/pop sound notable even on silent sections, and sometimes throughout the whole pressing. And generally worse on outer tracks, and often fixable by wetting during play.
So perhaps friction flicker and vinyl material variation at least plays a part in general surface noise crackle/pop ? Particularly in bad/degraded pressings.
Some quick calculations suggest that friction flicker noise might be significant in normal surface noise crackle/pop/ticks as follows :IF stylus-groove friction has natural random variation that follows a flicker law, roughly peak friction would be 12dB above rms level [IIRC]. RMS friction level is known, from Yosh's site/JVC figures and own measurements. Then we can estimate peak (flicker) friction.
Without going into detail for now, applying this peak friction force via a 20 deg VTA, and via a 25 deg tracking offset angle to a 45 deg groove wall, is calculated to be typically just enough to exceed VTF, even on a silent groove, dependant on friction coefficient.
So perhaps micro-mistracking does happen in normal, even silent grooves ? And this might be a significant mechanism for how surface noise crackle/pop arises ?
Here's a paper illustrating how (1/f or flicker) variation in friction force might arise in the stylus-groove interface. Stick-slip friction being often mooted as the vinyl-stylus mode, as referenced below.
In any event, it shows (perhaps) analogous test results and a model with a steady state friction element, plus a variable random element that has a 1/f or flicker profile. It is particularly interesting, because it also discusses the role of debris and loose material, which has obvious relevance to a vinyl-stylus environment. eg for debris read thin film of surface contaminant say from washing. However, the tests and model are not in a vinyl environment. But here's enough to be interesting, enlightening, and suggestive by analogy, IMO.
DEBRIS AND 1/f NOISE IN SLIDING FRICTION UNDER WEAR CONDITIONS
M. Duarte et alhttp://www.gef.es/Congresos/26/PDF/89.pdf
I also found this literature search which Klaus made and posted about 6 years ago here on VE (!) :
Klaus R wrote:W.r.t. an issue that was mentioned below, i.e. noisy records, here's what I could find in related literature:
Factors responsible for surface noise are:
Major contributor is the master tape recording.
Factors directly to vinly factors are :
1. Surface roughness : filler
2. Welding and shearing of asperities (roughness, harshness)
3. The associated plastic deformation : microscale intermittency of plastic flow : volumetric version of stick slip behaviour, slipping of molecular aggregates from one position of equilibrium with their neighbours to another, discontinous motion on microscale.
4. Thermal agitation of cutting stylus
5. Lead screw vibration transmitted to cutting head
6. Vibration of stylus induced by frictional drag, stick slip motion during sliding friction : each asperity (roughness) will first stick, then progressively experience elastic deformation in shear produced by the gross sliding motion, until finlly the shear stress becomes high enough to produce a slip either by rupturing the asperity or by casuing the adhering surfaces to separate. Note that stick-slip motion is capable of generating timing errors similar to digital jitter.
 Barlow : Limiting factors in gramophone reproduction, Wireless World, 1957, vol.63, p.228
 Hunt : On stylus wear and surface noise in phonograph playback systems, JAES, 1955, Jan., p.2
Perhaps there's insight into one of the causal mechanisms behind surface noise crackle&pop here. ie through flicker variation in friction force and resultant micro-mistracking. Then the noise phenomenum of the OP might be simply explained by reduced nett downforce, increased friction, and so degraded tolerance to normal variation in surface friction. Under conditions of tracing high acceleleration grooves (loud hf).
If so, quite a few other surface noise 'oddities' begin to make some sense too, IMO.
Here's a markup of one of the test result plots from the Duarte et al paper. It shows the model I think might apply to vinyl-stylus friction. ie a steady state friction element (1), and a random variable element (2) which follows a flicker law :
If so, one might improve surface noise (with this origin), either by improving 1 or 2. Or by improving overall cartridge/setup tolerance to coping with it. Some elements will be intrinsic to the vinyl pressing or treatment thereof, some to the stylus/cartridge, and some to the setup.[/quote]
Anything that improves stable downforce without increasing friction should help. I also think these would be very fast, short mistracking events, no time for the headshell to move, and so it's all about cantilever rigidity, suspension, and tip inertia, i think. Holding the stylus put, and delivery of the downforce.