Disadvantages
- Cavitation Erosion
- Loss of surface material due to microscopic bubble implosion (1)
- However, the simultaneous processes of surface cleaning and of surface erosion allow the optimization of parametric settings to maximize the cleaning efficiency, while minimizing the level of erosion damage (1)
- Testing must be performed to obtain optimum combination of cleaning solution concentration and cavitation level (4)
- Dependent upon many controllable factors
(Micro's quote is taken from a PDF document from the Rochester Institute of Technology, College of Engineering. The final footnote in my 3rd article cites the link)
Cavitation erosion is a reality. To prove this to your self hold a strip of tin foil in your USC bath as it runs. Depending on the thinness of the foil, the amount of time you submerge it and other factors (below) the foil will dimple or perforate. Records are not made of foil, but this gives some idea of the reality of ultrasonic 'strength'.
Cavitation erosion is a reality but it is not destiny. Several factors come into play including the freqency of the transducers and how they are deployed in your particuar ultrasonic record cleaner.
Lower frequency cavitation is much stronger and although fewer bubbles are generated, it's vacuum bubbles explode with much more force. The higher the frequency the greater number of bubbles, the smaller the bubble and the the gentler the implosive force. The relative difference in cavitation strength between 40kHz and 80kHz is roughly 10 to 1.
The effect of cavitation erosion is also influenced by the position of the transducers relative to their target.
Think of a pressure washer. Distance and force. <--
The 200W KLaudio machines feature (4) 40kHz transducers with 2 each aimed directly at each side of the LP at a relatively short distance.
The 300W Degritter uses (2) 120kHz transducers aimed at each LP side at (from what I can gauge by its picture,) fairly close difference.
AudioDesk does not reveal the power used or frequency of its single transducer that is aimed at the edge of the LP. My guess is it runs at 80kHz. Remember AudioDesk is not primarily an USC.
For contrast, the 330W Elmasonic P120H tank uses (6) transducers mounted on the bottom of a much larger tank aiming at the (multiple) record edges at a distance I'm guessing is 3-4 inches farther away than the KL and DG; these can operate at 37 or 80 kHz.
In my opinion, except for quality/reliability, these are the most important features that relate to cavitation erosion issue for the 3 single-slot desktop units.