Ultrasonic Cavitation & Cleaning Explained

Neil.Antin said:

What exact model of Sonix4 do you have? This was a USA made UT tank and this is best info I can find https://www.interguidedental.com/equipment/instantsearch/result/?q=sonix and https://www.dentalcompare.com/1186-SearchResults/?search=sonix . The operator's manual makes no mention of kHz - https://c1-preview.prosites.com/106982/wy/docs/Installation_Guide-Sonix.pdf

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It’s an older ST136H. I know that the Hz here is for the input power, not the transducers. When I bought it, it was specifically listed as being 60kHz, and the second link you provided shows exactly that in the specs (the versions with the H suffix have the built in heater).

It’s worth noting that I can stand next to the unit and not be overly bothered by the sound, my cat too, thus suggesting the higher operating frequency. It also takes was longer to puncture the tin foil, providing the same indication.

Neil.Antin said:

The dilemma is trying narrow down what caused the increase in noise in the outer grooves. It easy to blame the UT, but that may not be cause or the only cause. But, @rDin who has and has used the Kirmuss UT ~6.5-L machine which is 35-kHz and ~180-watts (the Kirmuss does spin faster ~1.5-rpm) for single record cleaning in his cleaning regime as pre-clean step before his Degritter and has done spectral analysis same as you, to my knowledge never saw the difference you saw with 60-kHz and 100-W.

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Yes, just to confirm that I continue to use the Kirmuss and Degritter, after manual cleaning, and *never* see anything like that added noise. If something is being added my guess would either be chemical residue that hasn't been sufficiently rinsed, or I guess ultrasonic damage of some sort? Anyway, just adding a data point here.

I'd grab a test record with a nice quite intro passage - and record it pre-clean - then clean with distilled only in the ultrasonic - see if noise is added - then if not, move to the chemical cleaning and check again.

abeidrov said:

As I said in my previous post, I had to do a separate rinsing cycle after adding 2ml of Degritter solution due to excessive (to my eyes) foaming. I also washed Degritter with several short cycles and one maintenance cycle with fresh DIW before starting medium cycles with records for rinsing. And immediately I noticed some foam in the water and on records as I was rinsing them! So, if you switch water tanks as Degritter recommends, you would have even more cleaning substance getting to your rinse tank with each cycle.

I’ve ordered a second tank, but now I am not sure I need it. I think a better process would be to do a batch of cleaning first, without drying or maybe add just one minute of drying, put your records on a drying stand, wash your Degritter thoroughly with several cycles of fresh DIW, wash you filter, wash your water tank. And then, put all the previously cleaned records through a rinse cycle with DIW plus IPA with proper drying. And you do not need a separate water tank to do it. What do you guys think? Does it make sense?

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Yes it does if you can do the cleaning before the records dry. I would not count on rinsing to free dried particulate.

abeidrov said:

And then, put all the previously cleaned records through a rinse cycle with DIW plus IPA with proper drying.

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I sometimes do similar with no ill effects I can hear. I always use the SOAK cycle in the Degritter. The idea being that it allows any dirt to soften before the ultrasonics start. And I run multiple cycles, typically three or four on MEDIUM as I find this really opens up the soundstage. It’s diminishing returns, but I feel it’s worth it. Four x MEDIUM is ~10 minutes of ultrasonics in total. Using MEDIUM+SOAK also allows the water to cool a little such that you can keep running and rarely hit the cooling function.

Neil.Antin said:

Well according to this https://www.dentalcompare.com/4720-...Ultrasonic-Cleaners/39318-ST136/?search=sonix, it is 60-kHz but it's also rated 180W, while this specifies 40-kHz https://www.allfordentist.com/st136...nd-timer-basket-and-amp-cover-prd-56654.html; and not make this any more confusing, this post indicates that there was three versions, https://www.diyaudio.com/community/...ultrasonic-record-cleaner.218276/post-5459172, a 40-kHz, dual frequency 28/40-kHz and 68-kHz.

Do you have the digital control or the rotary knob control - what does the front look like?

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It never did look like any photos online. As I understand it, while Sonix4 was a reputable company for a long time (a former Sonix4 engineer started offering custom built machines in that diyaudio thread), the quietly switched to 40kHz machines at a certain point.

I dunno. Maybe mine was never genuine? Or they always shared the wrong photos? It’s challenging getting consistent information.

Anyway, here’s the front of my machine:

rDin said:

Yes, just to confirm that I continue to use the Kirmuss and Degritter, after manual cleaning, and *never* see anything like that added noise. If something is being added my guess would either be chemical residue that hasn't been sufficiently rinsed, or I guess ultrasonic damage of some sort? Anyway, just adding a data point here.

I'd grab a test record with a nice quite intro passage - and record it pre-clean - then clean with distilled only in the ultrasonic - see if noise is added - then if not, move to the chemical cleaning and check again.

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FWIW, the rotation is currently 0.6rpm, and I rinse the record IMMEDIATELY after the cleaning process to try to avoid anything being dried in the grooves. But then of course I most recently followed this up with a full Tergitol cleaning and rinse that did nothing. This particular AIVS enzymatic formula is supposed to be a rinse-free formulation.

Dunno, folks. Maybe my machine is bad somehow, but I've owned it so long that I can't exactly get support for it from Sonix4. I can't say that I'm eager to risk another record on these experiments either. And I simply cannot justify the expense of a purpose-built machine like the Degritter, especially since I apparently need a new water heater and my wife bought Yet Another Couch (long story). So, back to the tedious scrubbing with Liquinox and Tergitol dilutions.

Neil.Antin said:

There are similar photos such as https://estatesales.org/online-auctions/sonix-iv-ultrasonic-cleaner-ss-52547997. The question is what is the kHz?

Back when I asked you to do the aluminum foil test, you showed pictures after 1-2 min. The photos show mostly dimpling with a few holes. If it was <60-Hz you would see more than few holes. A 40-kHz machine in a few minutes will punch more than few holes. Checkout this Degritter (120-kHz) aluminum foil test

Someone has checked the AIVS for residue by allowing a few drops to dry on a clean surface and nothing was left behind.

It is possible that the UT is cleaning out debris deep into the grooves that the Liquinox and Tergitol will not touch which is why for manual-sink cleaning I added an acid wash. There is risk when deep cleaning older records. There are aspects that will be better, such as better high frequency replay, but there are also aspects that may not be better such as a higher noise floor. Keep in mind, that under intense magnification, very smooth surfaces such as the record are not perfectly flat. And cartridges with highly profiled styluses (microfine, etc) can better read the surface.

If you decide to continue using your UT tank, first start with only DIW, increase spin speed to 1-rpm and reduce your duration to 10-min.

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Yeah, the "only dimpling" (mostly) and less obnoxious noise level was the main reason I didn't second guess it being 60kHz. And yes, I do use a MicroLine stylus (Audio Technica AT33PTG/II). If I find a record I don't mind risking in another test, I'll try the faster rotation and plain distilled or deionized water for the shorter duration as a power rinse.

Interesting... So they're dipping further into chemistry, and borrowing some tech from the AudioDesk for a new monster machine? As if their existing machine weren't already prohibitively expensive!

Also interesting that they include the chemical details of their new cleaning solution at 4:46 in the video. I'm curious to hear your thoughts on that, @Neil.Antin !

OK, at long last I finally tried a faster rotation (1rpm), shorter cycle (10 minutes), with just plain distilled water from CVS, with 2 records, starting bath temp 80F, ending temp about 82F. The difference is subtle but significant. On a 45 year old album that I'd cleaned twice with the Liquinox/rinse/Tergitol 15-S-9/rinse process on my vacuum RCM, the ultrasonic power rinse (and quick rinse/vac afterward) didn't remove any more clicks, but it did sound as though the overall noise floor was lowered, and some sounds that seemed over-driven and harsh previously felt more natural and less distorted. It's subtle to be sure, but does seem like an improvement. There's no visible difference in the waveform other than some occasional clicks seeming less prominent.

One curious negative of sorts is that whatever was removed by the ultrasonic power rinse must have been whatever there was left from the Tergitol clean that provided anti-static properties, as this power rinsed version was loaded with static after just a quick vacuum, then again after playback the record wanted to stay stuck to the platter in a way that I haven't experienced in quite some time. And that's AFTER blasting it with the Milty Zerostat after the final rinse/vac pass.

I'll try some more examples as time allows from my recent recording passes. It's good at least that 1rpm and 2 records for 10 minutes avoids any groove damage in the outer grooves!

Neil.Antin said:

Depending on your exact vacuum-RCM cleaning procedure - what concentrations were you using, and did you rinse between the Liquinox and Tergitol it is possible to leave some cleaner surfactant residue, and any surfactant residue can act as an anti-static since they are all hygroscopic to varying degrees. See the latest version of the book Chapter XIII and read the section XIII.5 Importance of Rinsing for testing that was done that showed the blower style vacuum-RCM does not remove all fluid from the surface - some is evaporated/dried in-place.

Although curious, you did not mention static as an issue when you previously cleaned records with your UT tank. But depending on your environment and how dry you got the record when you rinsed vacuumed dry, there is always the risk of inadvertently developing static.

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Yes, I rinse and agitate after each cleaning fluid pass, including between the Liquinox and Tergitol steps. But I generally just do a single rinse pass after the Tergitol. And no, I didn't notice static when I'd used the ultrasonic previously, though then I was using the AIVS Enzymatic for Ultrasonic fluid. Perhaps the extra turn or two of the clamp for the rotation to keep things tight made it worse? Dunno. It's not THAT dry in my basement/audio area. *shrug*