The calculation is made by estimating the area of the stylus contact patch then extrapolating to the square inch, using VTF as the pressure. The result is a frighteningly high number for pounds per square inch, but the calculation itself is totally bogus. The pressure on the groove is related only to the area of the contact patch and the VTF. The stylus tip is not contacting a square inch of the record surface obviously. As to the absolute requirement for a pivoted record cleaning brush such as the one that Mijo uses and the dust cover on top of that, I must be living a charmed life, because I use neither, and I have LPs that I have been playing for 40 or 50 years, and they are only minimally diminished due to stylus wear. And none of them have more ticks and pops than they did 40 years ago. I am just a careful person, not particularly astute about preventing dust etc. from landing on the surface of an LP. All of this is much ado about very little. Of course I have no way to know about other people’s listening rooms in terms of their dust problems or lack thereof.
I finally got a record cleaning machine. First thoughts.
As I previously mentioned, I was given a load of 78 RPM records which are filthy mandating a cleaning device if I want to play them. After months studying the situation I opted to get a Clearaudio Double Matrix Pro Sonic. A lightly used one came up so I jumped on it. Why this machine and not an ultrasonic cleaner? Several reasons. It uses fresh fluid for each cleaning and discards the waste. It sucks everything off the record. Even distilled water will leave a residue if it is dried by an evaporative method. It uses mechanical scrubbing which my instinct prefers over ultrasound. There is an ongoing argument over what ultrasound will do to shellac. The Clearaudio has a reputation for being very well made and it is.
As for it's performance the Double Matrix is fast, quiet and very effective. The fact that it does not drip fluid all over the place is amazing. Records come off spotless and bone dry. You can play them right off the machine. You can tell that each and every function of the machine was carefully thought out.
After cleaning new records that were played once before cleaning, there is no change in noise levels and there is no difference in sound quality. However, there is a noticeable improvement in turntable hygiene! There is always dust on new and old records. I see it when I clean my sweep arm between sides on black felt. Now there is all but zero and everything under the dust cover stays cleaner. THERE IS A MARKED REDUCTION IN STATIC! Vacuum platters will create huge amounts of static under dry conditions but every single record I washed develops none that I can notice. I am not sure why this should be the case but it is. Play a record not washed then static. Play a washed record then no static. The fluid I am using for vinyl records is a proprietary formula of distilled water, Triton X-100, Isopropyl alcohol and benzalkonium chloride. Obviously, this is not the formula to clean shellac, you'd melt it. In one week I am going to replay some of these records to see if the anti static effect is durable or not. My guess is it won't be. You might ask, why benzalkonium chloride? Fungus can live on vinyl. BAK is antiseptic. It also has surfactant properties.
Lastly, after playing 10 records that had just been wash I inspected my stylus under magnification and there was no residue on it meaning that the fluid and cleaning process left nothing in the groove the stylus could pick up.
Next I am going to clean some old really filthy LPs I got with the 78s and see how much I can bring them back.
I have never cleaned new records. My sweep arm collected any dust removing it from the path of the stylus and for decade this worked well. But, I am a clean freak and I like not having to clean the turntable after a listening session. After playing a record, once the vacuum released on removing the record I would frequently get a loud pop or two when the static on the bottom of the record arced to ground. The sweep arm discharged the top of the record during play so none of this affected the sound quality. Static does not turn 180 degree corners. However, it is nice not to have any static at all. So, there are positive attributes to cleaning records that go beyond reducing noise and improving sound quality. It is also fun to watch the Double Matrix do its thing. Worth $6500 for a new one? Only if you have extra money lying around or like buying used records.
OK, now you can beat me up:-)