DIY Ultrasonic Record Cleaner - What Frequency to Use?

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I plan to build an ultrasonic record cleaner. There are a number of nice DYI designs described here and on other websites (many thanks to those who shared them). All involve some sort of mechanism that slowly rotates vinyl records in a general-purpose ultrasonic cleaner with about 30% of the record surface in the fluid (mostly distilled water) at a time. These DIY systems are MUCH less expensive than the commercial purpose-built ultrasonic record cleaners – the Audio Desk and KLAudio each sell for about $4,000 each, and the Ultrasonic V-8 (which is quite similar to many of the DIY designs) is about $1,500.

When selecting the ultrasonic cleaner for use in building a DYI record cleaner, there are a number of alternatives. I think the inside of the tank needs to be about 11.75" long (minimum), which typically translates into about a 6 Liter (or larger) tank. These vary significantly in price, starting at about $150 and going up to many times that. I think they vary in quality, number and power of ultrasonic transducers, heating capability, etc., but a key point of difference is the ultrasonic frequency used.

Most or all of the least expensive 6L cleaners use 40kHz transducers. This appears to be by far the most popular frequency for most purposes (cleaning jewelry, dental instruments, gun parts, engine components, etc.). However, some believe strongly that higher frequency transducers (60, 80, or higher kHz) are much better for record cleaning. These are much less common and more costly. I don’t think the components or construction cost a lot more – the higher price appears to be more related to lower sales volume and less competition among the higher frequency models.

I'm trying to decide which general-purpose ultrasonic cleaner to buy. I want the lowest cost cleaner that will perform well for this purpose and not damage my records. I’m leaning towards an inexpensive 6L 40kHz cleaner, but I’m open to considering other alternatives. I've summarized the pros and cons as I understand them below.

40kHz cleaners
These cost less and are easier to find – though the inexpensive Chinese unites may have lower overall quality and/or durability. They are used successfully with excellent results by many people. They have a more forceful cleaning action than higher frequency units, which, while probably good from the cleaning perspective, causes some to be concerned about them possibly damaging records (they can definitely make small holes in aluminum foil, but I didn’t read of any clear evidence that they damage vinyl records – though some wonder if some of the debris found in the tanks after cleaning records might include bits of vinyl). Of the three expensive commercial Ultrasonic cleaners, both KLAudio and V-8 use 40kHz transducers, and Audio Desk may also use this frequency – it seems like I saw that someplace, but I’m not sure (anyone know what frequency Audio Desk uses?).

Higher Frequency (60, 80, or 120kHz units)
These are significantly more expensive and usually of high quality. They produce smaller bubbles that are known to be better at cleaning tight spaces (such as inside small holes in machine parts), and may therefore be more effective at cleaning deep in record grooves. These produce less energetic cleaning action that is probably less likely to damage vinyl records – though they may also be less effective at cleaning some items (a consideration particularly if you plan to use your cleaner for anything other than records).

My Conclusion (subject to change)
Since I think every review I’ve read of any ultrasonic record cleaner reported excellent results (both audible, and when the record grooves are examined under a microscope), my guess is that they both clean equally well. I’m not aware of any evidence that the smaller bubbles produced by higher frequency machines remove debris from a vinyl record that would be left by a 40kHz machine. It seems like “clean is clean” – and they are both effective at removing virtually all debris from the record grooves.

With regard to record damage, it doesn’t seem like the 40kHz machines are damaging to records – though it would be interesting to know if any of the debris removed by cleaning turns out to be vinyl – though even it does, it is possible that it was scratched loose by the stylus and is not a result of damage caused by ultrasonic cleaning. My guess is that the thickness and flexibility of record vinyl prevents the ultrasonic cleaning action from causing damage as it can to very thin metal (aluminum foil, etc.).

The fact that the $4,000 KLAudio machine and the $1,500 “V-8” both use 40kHz frequency transducers seems like pretty good evidence that it is effective and does not damage records. I think the incremental extra cost of using higher frequency transducers would be insignificant in relation to the selling cost of a machine like the KLAudio, and if there were demonstrable evidence that the higher frequency transducers were more effective, it would be a great competitive selling point that I think KLAudio (or Audio Desk, for that matter) would include and tout as an advantage over their competition. KLAudio says they tested higher frequency transducers, but they did not perform better (see below). My guess is that the Audio Desk also uses 40kHz transducers – otherwise, I would think they would highlight their higher frequency transducers as a selling point (which they don’t).

Information from Manufacturers

Here’s an excerpt from an email I received from the maker of the Ultrasonic V-8:

“Thanks for taking a look at the V-8. We use 40 khz frequency from 4 transducers. Other manufacturers also use 40-50 khz because the bubble size and energy level seems perfect for records. Some people…on internet forums speculate that 60 or 80 khz must be better since the bubbles are smaller, however they fail to account for the energy level in watts. We have delivered hundreds of machines and our customers love the results they get from the V-8, especially the fact that multiple records are cleaned at once.”

From the KLAudio FAQ:

What are the specifications and frequency of the ultrasonic transducers you use?
KD-CLN-LP200 uses four x 50-Watt, 40kHz ultrasonic transducers placed perpendicular to the LP disc (two on each side). The unit cleans and dries both sides of the record simultaneously.

In tests, higher frequency transducers (>100kHz) did not result in better cleaning of our LP records. Additionally, 40kHz is well-established in the cleaning industry and has reliable electronic drivers available.

Is your 200W ultrasonic record cleaner safe for my LP vinyl records?

Klaudio's KD-CLN-LP200 has significantly more cleaning power than other commercially available ultrasonic units. Our design applies a full 200W to the vinyl without causing any disc deterioration. This is only possible through our exclusive, patent-pending technology. This high amount of power would normally degrade the vinyl, but Klaudio has overcome this limitation after several years of R&D. (See microscope images of a cleaned disc.)

To demonstrate the safe application of Klaudio's cleaning system, a solid, brightly-colored disc can be used. The below blue vinyl disc was cleaned in an extra-hot 40°C (104°F) ambient environment to accelerate wear. The KD-CLN-LP200 cleaner was run for a continuous 9-hour period using a special relay board, which operated the ultrasonic transducers continuously. This prevented the cleaning cycle from ending like the retail model does every 1-5 minutes.

Afterward, it's evident from wiping out the reservoir that only dirt was removed. There are no vinyl particles or blue tint, which would indicate debris originating from the disc itself.

From Branson Ultrasonics (an excerpt from correspondence posted in another thread):

"...Ultrasonic cleaning is an aggressive method of cleaning as you are bombarding a surface with molecule. Some surfaces exposed long time to ultrasonics can erode. The aluminum foil is an example. But it only eroded the aluminum when the foil is thinner than 50 microns. In general 40 kHz used like you do on plastics will not erode a surface; if it did you should have noticed it."
 
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So you can save a couple hundred bucks buying a 40KHz unit and get cleaning results as good or as close to as good as makes no odds as a higher frequency cleaner.
I would guess that due to the more aggressive action of 40KHz the required cleaning time may be shorter as a bonus. I've been considering building a URC but been deterred by the high cost, and unobtainability in the UK, of the the higher frequency units.
Even if a 40KHz is only 90% as good as a 60K it's probably still better than the next best system

Thanks for the info Doug.
 
I realize that my purpose in this post may not be obvious (though it is spelled out in the title), but I was/am looking for feedback and/or information I may have missed to help me deicide wich ultrasonic cleaner to purchase as the basis for my system. Since this is the first and core decision for anyone who plans to build an ultrasonic record cleaner, I thought it might also be helpful to others to have a separate thread focused on this topic and summarizing key information (including the email I received from the maker of the Ultrasonic V-8). The topic is discussed in other threads here, but much of that discussion is buried in long threads that would take hours to read through, so I suspect many may miss it.

In a very long and interesting thread started by BBFTX on the topic of ultrasonic cleaners (currently at 120 pages, and growing), there seems to be a general acceptance of the assumption that higher frequency cleaners are better (at least up to 80kHz). I just noticed that a recent poster on that thread (see page 120) did some experiments that indicate that 60kHz works a little better on records than 80kHz. There still seems to be the underlying assumption that using a higher frequency than the common 40kHz is obviously better. I am challenging this. I understand that a theoretical case has been made for it, but I don't see any evidence that this has proven to be true when applied to cleaning vinyl records.

The strongest evidence of this to me is that at least two of the three expensive commercial ultrasonic record cleaning machines use 40kHz - and the makers of the $4,000 KLAudio specifically say that they tested higher frequencies and determined that they did not work better. I am not just proposing that a 40kHz machine is almost as good and much cheaper - I really suspect that 40kHz machines may be every bit as good or even slightly better than a higher frequency machines for cleaning records - though I suspect than any ultrasonic cleaner in the 40-80kHz range will probably produce indistinguishable results (i.e., thoroughly clean records) when used for an appropriate length of time.

I am, however, open to new information that might change my mind on this.
 
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What Frequency to Use and more

As a builder of Ultrasonic Cleaners (a former employee of Sonix4, now independent), I may offer a few insights.


It is true, there have been no reports for damage to vinyl records using the mass-market, Chinese 40khz Ultrasonic Cleaners. They do make a good, inexpensive option for cleaning your Record Collection.


The cavitation bubble formed by a 40khz unit is much larger and more powerful than those of a higher frequency (60khz, 80khz, 120khz, 135khz).


When the cavitation bubble implodes, it releases a jet stream and heat. The larger bubble releases a larger amount of power and heat (10,000 degrees kelvin, according to scientific reports, in minuscule amounts).



The 40khz cavitation bubble is too large to penetrate the record groove, but all ultrasonic cleaners rely on the jet stream to dislodge any debris.
The smaller cavitation bubble of a higher frequency cleaner can form inside the groove, next to debris and dislodge it.


Higher frequency Ultrasonic Cleaners generate MORE cavitation bubble than lower frequency units. More bubbles, more implosions, better cleaning coverage.


I frequently get asked which frequency is the best for cleaning vinyl records. I recommend the following:
If you collect albums that are in poor condition, such as mold or water damage, the the lower frequencies (40khz or 60khz) are the better option. (Many collectors buy from flea markets, estate sales, etc).
If your collection is already in good condition (finger prints and dust), then the higher frequencies would better suit the collector (80khz, 135khz).


Cleaning solution is vital. There are many formulas, but I personally recommend TergiKleen (or a formula similar) because it is archival and used by the Library of Congress for recorded materials.


Carefully monitor the heat in the tank, also. Even though the Heater may turn off the heating element, the act of cavitation will continue to release heat, which will cause the solution to go above the cut-off point! Heat will warp and destroy vinyl records.


To address the issue of cost, I say this: It costs me more than 3X for parts alone than what a Chinese Ultrasonic Cleaner costs! In my opinion, they are deliberately undercutting American Manufacturers.



Hope some of this helps.
-Louis

Vibrato, LLC.
 
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