Thumbs up for ultrasonic record cleaning

@whart That's what I thought - KL discourages use of any add-ons no? Honestly, I'm sticking with alcohol just by some inertia. I like it for its grease dissolving properties. Also as far as I understand, it actually makes the 40kHz cavitation gentler by lowering  water's surface tension. Having said that, next tank solution I'm gonna try will be just water + 0.05% Tergitrol, excactly as used by the Congress Library and see if I get less clicks n pops. I also tried pure water US but I'm a bit afraid it may be too aggressive
plus I like the Tergitol solvent properties.

@fleschler 
You say, "I think your method of US is using 10 C degree too hot water and 100% too high a cavitation frequency. Maybe that’s why you can’t hear the difference on 3-6 posting; however you state you did see and hear the difference using this method on 2-6 post."

The one posting was about a routine involving 2 records at inadequate spacing, temperature, and rinsing. Improving these helped. The other posting was an experiment to explicitly test the hypothesis that one record would be damaged (it wasn't).

The differences were: more energy per record and very high temperature on one sector of the record in the test, higher temperature on the bulk of the record and better rinsing for the routine cleaning. Don't quite see how you conclude that 45C is too hot and US frequency is 100% too high. Also, don't quite see how this explains the results.

Cleaning efficiency vs frequency is graphed on the DIYAUDIO thread, if you are interested.

@dgarretson

I prefer the 80KHz setting because of the graph of cleaning efficiency vs frequency on DIYAUDIO, although I cannot say that I’ve found a reliably detectable difference. Just a theoretical one!

The big thing is that the wavelength is much smaller, so that there is plenty of room for the wave to develop on all sides, so no disappointing surprises when you play that record in 6 months time. Also, 80KHz is quieter. And as you note, it doesn’t heat the chemistry up as much. Me lazy.

I've purchased ebay records where the seller used the KLAudio.  The records are nearly mint; however, they are missing their highs.  Multiple copies (I've given six of them as gifts cleaned on a VPI 16.5) of the AMERICAN PERCUSSION SOCIETY PRICE URANIA have all got fantastic highs but the KLAudio cleaned copy is like someone filtered off the highs.  This is the third ebay US cleaned record I received sounding like the highs are missing.  A friend has the Audio Desk and mentioned that the KLAudio shoots the cavitation directly at the disc versus below the disc surface and wipes out the highs.  Kirmuss Audio claims the higher frequency and temperature can both harm the highs and warp the record.  Why take a chance on higher than necessary frequency and higher temperatures if reducing them is safer?  

@fleschler- You have it backwards. A higher frequency US will have lower energy release and it will be much more evenly distributed than lower frequency. The cavitation bubble size is inversely proportional to the frequency; the higher the frequency, the smaller the bubbles and the lower the energy release when they collapse. The smaller bubbles are also more effective at removing smaller particles than larger bubbles (lower frequency), especially between the grooves. The Kirmuss RCM is closer to an industrial cleaner and should be avoided IMHO.

Higher temps facilitate cavitation and will increase the energy release, which may not be desirable if you are worried about damage. Adding surfactants and IPA will also increase cavitation. Whether this is advantageous or not depends on frequency, power, chemistry of the bath, distance from the transducers, volume of the tank, coupling efficiency of the transducers and matching of the drive signal for both impedance and frequency of the transducers.