Thumbs up for ultrasonic record cleaning

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.

I too have bought many records which appear NM, but play poorly. Just to note, most records look NM after a US cleaning (scratches excepted, obviously). Nevertheless, a well used record plays that way, no matter how it looks.

My experiments, 80KHz and 45C with an Elmasonic, would appear to contradict those claims. And in my view, experiment is the ultimate arbiter.

@terry9 Could you pls link to the diyaudio graph? Thanks

fleschler

I've purchased ebay records where the seller used the KLAudio. The records are nearly mint; however, they are missing their highs

I don't think there's any correlation between the lack of highs on these LPs and the use of the Klaudio machine. I have a Klaudio and have not experienced this problem. When I first got the Klaudio, I actually went to the trouble of recording to digital both before and after samples from a few records, and then compared the waveforms. I didn't see any damage to the discs, and haven't suspected any damage since.