Degritter brand ultrasonic record cleaner

I can't speak for anyone else, but the LP's I bought from Tom Port are no quieter than those I cleaned myself. But then, those LP's were acquired from Tom many years ago; perhaps his current cleaner does a better job than the one he used on my LP's.

Kirmuss uses a pretty ubiquitous ultrasonic bath* with the addition of a proprietary spinner that uses multiple slots rather than a rotisserie like the Vinyl Stack. He also uses a fluid that he claims removes all sorts of nasties left over from prior bad cleanings. I haven’t used it- there’s a fair amount of anecdotal information on the Hoffman forum about having to repeatedly clean to remove a paste-like residue that Kirmuss claims is the result of built-up contamination. Judging from those comments, which you can read yourself, it’s a pretty time intensive process.
I don’t have an issue with his introducing a low cost entry into the ultrasonic sweepstakes, but some of his claims are, well, a bit extravagant.
If you can ante up for an Elma, another fine piece of German engineering (sorry about your MB, @tomic601 - my favorite was a ’69 300 6.3- sort of a short wheelbase 600 with oodles of power), you’ll spend more but get a better quality US bath. Add a water recirculation filtering system for less than 100 dollars and the Vinyl Stack and you are in business for more than the Kirmuss but still far less than the AD or KL.
*One claim he does make that I agree with is the position of the transducers on the bottom of the tank, rather than at the sides; given how wave propagation occurs, the LPs act as baffles if the transducers are at the sides of the machine. 

One of the reasons for 40 khz is that the resonance of water is right at that frequency. 41.2khz, approx. IIRC.....

So a 40khz ultrasonic resonator is designed for that frequency and then to wander in that range (+/- 250hz, approx) until it finds the lowest reflections of energy in the resonator and the highest rate of transfer. So not the water resonance really, but the best condition of energy transfer through the medium of water.

This comes out of the ultrasonic sealing industry, the place the ultrasonic resonators at’ 40khz’...come from. Most times they work with water-based products like toothpaste, creames, hair shampoo, etc.

In that, I’m not sure what is accomplished with 120khz. Other than cavitation and heating at the surface of the resonator. Maybe the odd photon.

I’m ready to be wrong about all that, in the face of other arguments. We shall see, kinda thing. Not negative, just neutral.

A bigger number is not automatically better, is the deal, ....but...there may be good reasons to go to 120kz, and such hardware would likely take some tuning, tied to correct analysis...in order to get it to the right spot.

 @whart Thanks so much for referring the Elma.... I need more German stuff in my life :-) I can heartily recommend Brinkmann anything... ha

my manual but hyper trusty Nitty Gritty is fading....

@tomic601 - no problem. If you do go ultrasonic, don’t get rid of your vacuum machine. I find that ultrasonic is not a complete answer with older records that have been exposed to who knows what.
@teo_audio- your comments about the resonant frequency of water fascinated me, so I did some quick and entirely inconclusive reading. There was a fellow named Keely who did some experiments back in the late 19th century experimenting with "etheric forces" and water. There was a mention of a sympathetic frequency a little above 40kHz where water shot through a tube and blew a hole through the roof of his lab!

I think a lot of the information we have about ultrasonic cleaning of records is anecdotal and extrapolated from other fields. I don’t know that anyone has funded any independent research on the subject that has resulted in published papers. I gather that some of the work done by the fellow that developed the AD is considered proprietary.

One person who visited here briefly to discuss ultrasonic cleaning said he measured the frequency of the KL at around 35 kHz, rather than the 40kHz claimed.

One constant seems to be the question of damage- which I have found no evidence of in my use of several different machines. The theory is that the higher frequencies generate smaller, less powerful bubbles which are less likely to cause any pitting. Part of the reason for the spinning of the record is to avoid this sort of damage, though I have not tried to damage a record deliberately using ultrasonic machines.
I think the days of major companies funding research in these areas is long gone-- there is little economic incentive to do so and most of the companies in the market in the record cleaning space are small operations, or are using US baths that are designed for industrial use, not necessarily for cleaning records, e.g. Elma, who make equipment for labs, dental and medical, industrial applications, etc.