COF said:
Do I understand correctly? Previously you had a video demonstrating 3 fan settings, low, medium, high. But now you've increased the available fan settings to 20 , for even finer grade selection of the fan noise?
Yes, we redesigned the fan power settings a bit. You can now pick between 1-20 settings and while doing so the machine turns on the fans so that you can hear the difference of each setting in real time.
tima said:
Does the amount of applied power change vacuum 'bubble' size?
No, it does not. The vacuum 'bubble' size is mainly determined by the frequency. What you do get from applying more power is more 'bubbles' and a better cleaning energy distribution.
tima said:
Does the amount of applied power change water/soultion temperature?
Yes, more power causes the water/solution temperature to rise quicker. This is the down side.
tima said:
Is it possible to correlate power (wattage) to cleaning effectiveness or implosion force? Could such a correlation hold across any commonly used transducer frequencies?
To the cleaning effectiveness, yes, to the implosion force no. The implosion force is determined by the 'bubble' size. Cleaning effectiveness is affected by both the bubble size and the number of bubbles you have (there are other aspects as well that have effect on it, like solution temperature, solution surfacetension, the acoustic parameters of the cleaning tank, etc. ).
tima said:
I read some Degritter literature some time back (when spirit was first telling his beta experience) and it said something like: 'Our use of 120kHz is gentler and safer than other commonly found lower frequencies in other machines.' (Not a quote, but that was my takeaway.) I don't know if your literature still makes a claim like that. Does using 300W in a smal tank mitigate the 'gentler, safer' claim or change it in any way?
This claim is based on the size of bubbles and implosions due to the higher frequncy. The higher the frequency the smaller the implosions and the gentler the cleaning effect. This claim is backed by scientific publications on the topic and we can provide citations.
This in return does not mean that 40kHz is inherently unsafe for Vinyl. We have not run these tests and we cannot say whether it is or isn't. Even if the 40kHz is harmful in some configuration, then there are solutions that can be done to mitigate it. For example KLAudio has patented "wave breakers" that block "hot spots" in their machine.
tima said:
Claims/statements about transducer frequency and particle size removal are pretty common in the ultrasonic cleaning industry, though fewer in relation to cleaning vinyl records specifically. Can you share what Degritter studies have found?
Back in 2016, before setting on the 120kHz frequency we ran tests with off the shelf ultrasonic amplifiers and transducers for 40kHz, 80kHz, 120kHz. The tests had transparent record covered with dark dustmixture sitting in prototype ultrasonic tank. The 120kHZ had the most uniform cleaning distribution. The aplifiers and transducers were from different manufacturers, so the test results might not have been entirely conclusive, but we were satisfied, as they also matched the literature published on the topic.
We have plans to publish the reasons behind our design decisions in a series of blog posts, but so far we have had too much at our hands to get to it. However, we hope to get to it once the first batches of machines are ready.
tima said:
Have you found similar relations between particle removal and frequency for vinyl records?
It is very difficult to study the exact effect of a frequency on a certainly sized particle. You need very good lab set up (preferably with electron microscope) and you have to spend a lot of time in ther to conduct countless tests with different particle sizes. It would require a research paper to prove (or disprove) the mentioned graph (I presume that there is one behind it).
We did study the effect of our ultrasonic cleaning on a graphite dust (particles of size 1-5um) in the University of Tartu. The images can be found in our webpage.