The Wear and Care of Records and Styli

[VinylandValves]

This was the title of the first and probably still the most intensive research project on the topic and it was published in 1954 by Harold Weiler of New York only a handful of years after the introduction of the microgroove record. Weiler's study was so comprehensive the Shure Brothers quoted it on their website as the last word on the topic. (Consider that Shure cartridges were considered amongst the leading offerings many, many years before the advent of the internet.)

 

The microgroove record is today's standard and superseded the old 78. It came into being around 1949 and introduced grooves 2.5 times smaller than the previous standard. The other major change was  change in playback speed to 33 1/3 rpm and along with an increase in diameter from 10" to 12" greatly increased the amount of recording time available leading to the epithet LP short for Long Play.

 

But back to Weiler's study. At that time, styluses were made from sapphire (diamond was considered too hard!) and had a very short life, some 30 hours compared to diamond at around 1000. Retailers of styluses introduced a service whereby customers could have their styluses checked under microscopes for wear, worn styluses being left behind at the counter in boxes often marked "Needle Graveyard". Weiler collected many of these used styluses and along with questionnaires forwarded to many thousands of dedicated record aficionados was able to deduce the chief causes of record damage caused by stylus wear, the basis of his published work.

 

Weiler also went on to test the materials he found stuck to these discarded styluses. What he found and the conclusions he drew were outlined as warnings to the participants in this very new recorded music technology, which we will look at in our next piece on this topic.

[audiofeline]

There is an interesting thread on VinylEngine started a few years ago.  Ray_parkhurst tried to address the lack of recent quantitative data on stylus wear by conducting an exploratory experiment on stylus wear.  Some interesting findings, with lots of questions arising. 

https://www.vinylengine.com/turntable_forum/viewtopic.php?f=19&t=113013&sid=fd4ce6737cc1eaa973eb846c9ffe0ec1

 

I am surprised that there is not more research on this subject, especially from the days when records were the dominant music reproduction format.

[GregWormald]

Really clean records reduce wear—a lot!

When I sent my Linn Troika off for a new stylus at 1500 hours, the re-tipper said that there was about 25-30% life left before vinyl damage.

I had it done anyway.

Since then I've gone to ultrasonic cleaning so I'll be interested to see how that affects wear—it has certainly improved the sound.

[robfoll]

I remember my local record shop having a big microscope for 'needle' checking. I still have a very high power pocket microscope that I used to inspect my stylii for cleanliness in later life. 

[VinylandValves]

In 1954 it was a revelation to Weiler to discover that even those who, in order to obtain realistic reproduction, had acquired expensive “radio-phonograph” and high fidelity reproducing equipment, were not entirely aware of the important part played by the stylus in record reproduction and record wear. Some 70 years later it seems a combination of changing attitudes to maintenance (our throw-away society) and perhaps a failure to properly understand the physical relationship between stylus and record groove means this topic remains truly relevant. Why spend up on reproduction equipment yet fail to ensure maximum protection for the stylus/record interface? Not only does this increase costs through accelerated stylus wear, left unchecked stylus wear will permanently damage record grooves resulting in degraded sound.

 

Stylus wear is caused by the friction of being dragged through the record groove, hence the stylus is polished an extreme degree of smoothness to keep the friction against the groove walls to an absolute minimum. It is worthwhile to consider that whilst tracking force might be set at a couple of grams, calculating the concentration of pressure at the two tiny points that the stylus contacts the groove wall we find an effective pressure of many tons per square inch. Considering that with each play of one side of a 12” LP, the stylus tip will be vibrating its way through more than one kilometre of groove and reaching speeds of 26,000 m/s2, it is imperative that grooves be as clean as possible if wear is to be minimised. (See also The Impact of Fine Particles on a Vinyl Record at https://vinylrecordcleaningsystem.com.au/pages/technical).

 

So what happens when the stylus wears? Wear occurs at the two points the stylus contacts the groove walls (note, the stylus does not contact the base of the groove) and if left unchecked the rounded edges of the stylus contact points wear flat. Where once the rounded edges of the stylus would glide over the groove modulations, these ‘flats’ will increasingly act like cutting tools, shaving off the peaks of the modulations causing permanent loss of sound information. The amount of record damage, distortion and the reduction of tonal range due to a worn stylus increases in direct proportion to the size of the flats on either side of the stylus tip.

 

The wearing process will of course be hastened by dust and grit which the stylus tip will grind into the grooves increasing the abrasive action. In figure 17A, we see a new tip shown in cross section sitting in the groove. In figure 17B, the tip is demonstrating wear and no longer sits properly in the groove and with further wear will present as in Figure 17C where damage to groove modulations has begun, which is permanent. The other impact of stylus wear is distortion. With the tip shape now changed, in fact narrowed, the stylus will sit lower in the groove and fail to faithfully track the groove modulations producing distortion in playback.

 

As a note to restorers of old collections where those collections were possibly played with worn styluses of older design; it is possible a modern stylus of the micro-line or micro-ridge shape, with their longer contact edges, may enable tracking of undamaged groove wall. That said, these modern stylus designs with their finer contact points are more susceptible to noise caused by groove detritus making an investment in pristine grooves even more important.

 

[cafe latte]

On 25/07/2021 at 12:58 PM, GregWormald said:

Really clean records reduce wear—a lot!

When I sent my Linn Troika off for a new stylus at 1500 hours, the re-tipper said that there was about 25-30% life left before vinyl damage.

I had it done anyway.

Since then I've gone to ultrasonic cleaning so I'll be interested to see how that affects wear—it has certainly improved the sound.

If there really was 1500 hours your retipper was not able to see wear as in my experience 1000 hours even with Micro Ridge the stylus is bottoming out. Micro Ridge last the longest and at 1000 hours there is still fin left but the point at the bottom is starting to get close to cutting the bottom of the groove as the wear patches meet.

Chris

[VinylandValves]

No way you'd want to be using this stylus. Forget "bottoming out" those flat would be shaving the tops off peaks. May as well throw out the records too.

 

Ultra sonic? If you really want to improve sound you'll be trying The Vinyl Record Cleaning System and VRC Restore!

[VinylandValves]

As to the impact of dust on records, testing first proved in 1954 that air-borne dust and dust worn from the stylus tip itself are the greatest cause of excessive record and stylus wear. Complete removal of dust and grit from the record grooves resulted in increases of up to 60% in the useful life of both records and styluses.

 

Why VRC? Because only VRC Restore! breaks down binder substances that weld grit like stylus dust (ie diamond dust) to the groove walls. Alternative methods, such as ultrasonic, merely shake loose the unbound materials.

 

The trick when cleaning records is to achieve 100% removal of the slurry created when the wet cleaner goes on. As wet cleaning lifts the muck at the bottom of the groove, where the stylus does not reach, if 100% of that slurry is not removed then the fine particles are lifted up and deposited on the groove walls. (That's why you're left with that nagging question about the faint muddiness in the sound.)

 

As to the bits welded to the groove walls, that's a whole other challenge!

[cafe latte]

8 hours ago, Vinyl Record Cleaning Co said:

No way you'd want to be using this stylus. Forget "bottoming out" those flat would be shaving the tops off peaks. May as well throw out the records too.

 

Ultra sonic? If you really want to improve sound you'll be trying The Vinyl Record Cleaning System and VRC Restore!

Micro Ridge dont form flats like a normal stylus the fin keeps the wear flats the same size thought the life of the stylus. The Micro Ridge is the longest lasting stylus and in its case bottoming out will happen way way way before the fins wear out so bottoming out is the issue.

I agree though large wide flats literally shave vinyl away.

Chris