Investigating if ultrasound is harming LPs


Take a piece of a LP and US clean it.

With a precision weight scale. Taking the weight before and after the ultrasound cleaning. To determine IF any material is removed from the LP or not with the ultrasound usage.



The things that are needed for the test setup:

  • US DIY 6L cleaner. With 180 watt at 40 kHz.
  • Weight scale 2 decimals of a gram and max 5g capacity.
  • A piece of a real LP record 



First I selected a LP and tried to cut out a piece that is as close to 5 grams. To get the maximum size as possible that the scale can support. Tried to get a piece that includes lead-in to lead-out. To especially get some of the "glossy" part of those.


I used the US cleaning to do an initial cleaning of the record ~5g piece.


When I was not interested in weight loss due to dirt coming off. I need to start with a clean piece that is just the LP material and nothing else. When the goal is to determine if the ultrasound is removing any material or not. 


For the US bath I used a little bit of heat 30°C and reverse osmosis RO water (more or less the same as distilled water). And some wetting agent.

When we want the scrubbing bubbles being able to work into the groove. The piece of the LP will hang in the water like a record is and not lay down in the bottom of the US bath tub. 


I will run the US machine timer set to 30 min. That in practice a LP is less than half of its area at any time in the bath. That means more than half of the LP area is not in the bath when the record is revolving during a normal cleaning session. So in practice by having this piece submerged and US cleaned effectively for 30 min is like someone is spinning and cleaning in the US bath for more than one hour ! So it is more correct to see this 30 min as over an hour of US cleaning if it were a whole spinning LP. 


For the weight scale I make sure that the LP piece is clean and dry. And I try several times to rule out deviation between measurements, if any. Method where I learned to put the piece of LP on the exact same place on the scale plus I for each measurement looked that it went back to 0.00 g when I picked up the piece. I also reseted by pressing tare and looking again so I got 0.00 before putting the piece on the scale to get a new reading. 


Calculation example if we have a 5 g piece and 1% of its material were removed. Then that 1% should weight 0.05 grams and 0.5% should be 0.025 gram. That is what I see no issues to detect on the weight scale when the repetition accuracy is greater than 0.025!


So this method should be able to detect if less than 0.5% of the LP were removed by the scrubbing bubbles by the ultrasound and it's usage of it. 

But I was not expecting what happened below..


1st try Results

The start weight of the cleaned LP piece:

  1. 5.01 gram
  2. 5.01 gram
  3. 5.01 gram
  4. 5.01 gram
  5. 5.00 gram
  6. 5.00 gram
  7. 5.01 gram
  8. 5.01 gram

Average: 5.0075 grams.


After US bath "cleaning" first weight session:

  1. 5.02 gram
  2. 5.02 gram
  3. 5.02 gram
  4. 5.01 gram
  5. 5.01 gram
  6. 5.01 gram
  7. 5.01 gram
  8. 5.01 gram

Average: 5.01375 grams.


Hmm here is something fishy business going on between the weight sessions..


After the first US bath "cleaning" second weight session:

  1. 5.02 gram
  2. 5.02 gram
  3. 5.02 gram
  4. 5.02 gram
  5. 5.02 gram
  6. 5.02 gram
  7. 5.02 gram
  8. 5.02 gram

Average: 5.02 grams.


So there is something going on between weighting sessions..

I have taken those two weighting sessions and the average of the 2 x 8 measurements is 5.016875 grams.


Second try cleaning 

Now I am repeating the 30 min (one hour see above) Ultrasound treatment/"cleaning" for a second time.


And will weigh it also in two sessions and see what we get.

After 2nd US bath "cleaning" first weight session:

  1. 5.02 gram
  2. 5.02 gram
  3. 5.02 gram
  4. 5.02 gram
  5. 5.01 gram
  6. 5.01 gram
  7. 5.01 gram
  8. 5.01 gram

Average: 5.015 gram


After 2nd US bath "cleaning" second weight session:

  1. 5.01 gram
  2. 5.01 gram
  3. 5.01 gram
  4. 5.01 gram
  5. 5.01 gram
  6. 5.01 gram
  7. 5.00 gram
  8. 5.01 gram

Average: 5.00875 gram


So after a second US cleaning round and having the 16 measurements from the first US cleaning round.

Average from the two measurement sessions is after the 2nd US "cleaning": 5.011875 grams.



Is that there might be some deviation between measurement sessions of some reason that I can't explain:

  • Maybe it would average out if I took more than 8 measurements.
  • I should take more than only 8 measurements before the first UC cleaning session, which is why I later doubled them.
  • And I felt that I got better and better in my measurements routine. So the later measurements are more stable and have higher repetition accuracy than the first ones had.

I could leave the first iteration out from this post, but I wanted you all to see the whole process and not manipulate the findings.


Of the conclusions above I feel and believe mathematically with more samples that the second round is the one to look at and dismiss the first round.


Before I did the second US "cleaning" the average weight of the 16 measurements were:

  • 5.016875

After the second US "cleaning" the average weight of those 16 measurements were:

  • 5.011875

5.011875/5.016875 = 0.999003363647


Almost 0.1% (0.0996636352%) less weight after the second US cleaning.


That can be one of two things or little bit of both also:

  1. Measurement deviation before and after measurements. And more repetitions and measurements could be done. But I will stop here.
  2. That actually a VERY tiny part is removed of the LP by US


It is up to you guys to decide what you believe the data means. 


But remember it is a rather powerful US with 180W and in practice a very long US cleaning session as explained above.


Another note in the method of what I observed was that the little LP part were moving around in the bath when it were only hanging in a string. Usually a record is more firm and stable when the scrubbing bubbles are acting on its surface. If that makes any difference for the outcome but worthy of a note.

​​​​​(I got images on all the things and measurements 40 (!) But this forum is making it hard for me to attach them here)



Way out of the limits of your scale. FYWIW scales are robots that measure the voltage or current to hold them in position and translate to mass. That would be a very expensive scale at that weight and resolution. 

Yes, I addressed some of the issues myself in the text above:

About I noticed that I as operator got better and better in the weighting procedure that the first ones is not that repetition accurate.

Yes, we are not interested in if the piece is weights on that scale 5.02 gram when it actually on ANOTHER weight scale that is tared and calibrated and show that the same piece actually weight 5.15 gram. That is not interesting when nobody cares about what that specific scrap part is weighting.


The interesting part is the repetition accuracy between measurements and as we can see of the 40 measurements the VARIATION between all of them is only 0.02 gram from the heaviest and the lightest measurement result. And those 40 weight data points is spread over 5 sessions and a operator that getting better and better at it, so the first session that resulted in the lowest reading (5.00) maybe would not appear when it were in the first session that I were not as good as in the later sessions. Then we would be down to a variation of 0.01g. (So we could have a operator and a weighting scale that can reproduce weighting with a repetition deviation of ~ ±0.005 gram. if we consider that there were no reduction in mass from the US cleaning sessions..)


So I have seen weight scale with 3 decimals of a gram but I guess that it really doesn't matter if we see deviation of weight in that higher resolution for only a 5g piece, then we are down to reading more of the operator repetition accuracy between measurements. And repetition accuracy between sessions, room temperature and below 0.1% in total weight difference that maybe theoretical 1h of US cleaning might have caused(!) 

And no record in any shelf on the planet has undergone that heavy US cleaning in my believe. 

In other words higher resolution will more showcase other external factors (some of them accounted for above) than what we are really trying to get a answer to.


Methodology is a problem. Measurements need to be more precise. More sample points to do statistics. And then, have to decide what is gone - dirt or vinyl, and why?


Too many variables to draw a conclusion.

Regarding if it is dirt or not that were removed then read the text again I stated that I used a initial US cleaning before I started the testing, so that ALL dirt were removed when I am only interested what US did with the plastic and if it eroded the material. So the method and variable of regarding dirt were accounted for and removed.

Yes I did note that the piece were hanging lose that were nothing that I had thought about when I started but noted that it might be a issue. I think that maybe the ultrasound is acting on all sides simultaneously (the scrubbing bubbles). And I have previously when testing the efficiency of the US unit that I have tested with a aluminum foil dipped in the bath and the US shredded holes in the metal in less than a minute. As just a example of something else that were not rigidly fastened the US had no problems to work on the aluminum foil.

But of course I believe it is better to maybe use steel wire to hold the piece steady and mimicking how a record is held!


So there is potential methods improvements to be done. But I have not seen someone else trying to do the same thing at all when we have all of the tools and the ability to make this rather easily.

A YouTube friend said that Michel Fremer had US cleaned a red vinyl and tried to see if he got some red residue in the bath afterwards as a method.

I have read somewhere someone that had a "precision" scale and if that it were PVC pipe and not LPs that they treated with US session.

Anyway when seeing what US can do with metal and the power of it then that is raising the question for me what US is doing with LP records.


to in your case, generate junk science….

I hope that this can be considered as a starting point and show case that it is possible to do. Plus that it might inspire someone and giving some ideas. If someone would like to try and test. Let's us be positive and creatively contribute. But thanks for regarding my experiment 🥼 as science. 


But the good thing with this first shoot don't reviled that it is a disaster to use US cleaning at this point maybe if we get some process/methodology improvements might change that view, but hopefully not.


Using a non-destructively obtained sample (i.e. an entire vinyl record) would be more representative of any potential real-world implications.

I see that there is a issue with the method that I needed to take. When I don't have any wight scale that has enough precision and repeatability accuracy to weight a whole LP (~120-200 g). 

So the scale i used can measure max ~5g. And I still believe if I get the 5g piece to be more rigidly suspended in the bath. Then it is maybe good enough and a step better than other previously mentioned methods above. The positive thing is that 30 minutes in the bath is more than 1 hour if real-world implications is used. And when the theoretical erosion is so small then and hard to detect so we need to run US on the material for a extended duration to be able to detect that small erosion if there's any erosion that is occurring at all to begin with.


First you let it soak and wonder why it's heavier. Vinyl record isn't completely water-proof and able to soak water especially if it's completely submerged into the powerful bath.

Yes, i did let it dry after the "soak". But are you implying that the "vinyl" material is porous? (Remember that the stylus read ridges smaller than one micron then the porosity need to be smaller than that and not detectable by the stylus)

And I need to dry out liquid that is "induced" into the material and not only on the surface of the vinyl. Do you have issues with surface dry records that were soaked cleaned and afterwards put in a plastic bag (Inner sleeve). With some condensation and moisture in the inside the bag should be seen? I have not experienced that anyway? Should be seen if liquid is trapped in a bag!

I don't believe that LP material is soaking up liquid so that is in my eyes only spreading FUD in a sense. And lastly it got lighter (0.1%) after the second US bath so the theory that it holds water fails in that aspect also. But you might have other experience?

On the other hand the drying step is important and I did not weight wet material of course.


This was the another reason I did the experiment to remove any FUD about usage of US cleaning method. Regarding if or if not it erodes material from the grove.