Vacuum Record Cleaner Rreplacement

@oberoniaomnia 

You and @ljgerens are both right .  At the macro level, running an ultrasonic machine does not warm the body of water to any appreciable extent.  Hence my Vevor has a thermostatically controlled electric heating element built in in order to adjust the bulk temperature of the water.

On the microscopic scale however, things seem very different.  Remember that temperature measures molecular kinetic energy.  With ultrasonic waves creating cavitation followed by implosion, some molecules become very agitato indeed - possibly about as hot as the surface of the sun according to Wikipedia.  But there is insufficient time to transfer that heat to things it could damage.  It is a bit like the quantum theory of 'empty' space, where particles are created and annihilated at random.

Cleaning is caused by shock wave from the collapse of cavitation bubbles, see Wayback Machine for a scientific exploration.

From Ultrasonic cleaning - Wikipedia

An ultrasound generating transducer built into the chamber, or lowered into the fluid, produces ultrasonic waves in the fluid by changing size in concert with an electrical signal oscillating at ultrasonic frequency. This creates compression waves in the liquid of the tank which 'tear' the liquid apart, leaving behind many millions of microscopic 'voids'/'partial vacuum bubbles' (cavitation). These bubbles collapse with enormous energy; temperatures and pressures on the order of 5,000 K and 135 MPa are achieved;^[7][8] however, they are so small that they do no more than clean and remove surface dirt and contaminants

"tubes have nothing to do with gain in some circuits."  Those would be solid state circuits, because otherwise, even if you use a SUT, most of the gain, even though the phono stage is in MM mode and making, say, only 40db of gain, the SUT is typically supplying another 20db or maybe 30db if cartridge output is really low.  So even in that case, most of the gain comes from an active tube based gain stage.  As for surface noise, in my experience that varies wildly from one LP to the next. But most of the time, surface noise is not intrusive, in either of my two systems. It's there for sure, but only becomes evident when you change from a quiet LP to a very quiet LP.  And that's where surface cleaning can help. I listen "loud" by the way. My impression is that surface noise is more evident in between bands, and that may be related to how LPs are cut. So I don't really care about surface noise until there is also music, when it typically recedes to below some mental limit that would make it annoying.  If it IS annoying, the LP goes into the bin.

@audphile1 

Like you, I am trying to make sense of the "no surface noise" debate.

Most audiophiles will agree that every component adds noise to some extent or other.

Some other factors to consider include the type of music being played.  Surface noise hardly bothers me on most jazz tracks I have played, because the average volume is so high.  I imagine the same applies to other genres like heavy metal.  And DJs are known to 'scratch' records by performing unnatural acts on turntables .

Records seem to achieve a signal to noise ratio of about 60 to 70-dB.  But big orchestral music has dynamic ranges of 70 to 90-dB.  That's probably why I am so sensitive to imperfections in the quiet bits!

Then there is the difference between solid state and valve amplification.  Valves, as I understand it, have substantially more thermionic noise than solid state, because they run hotter.  So there is the potential for valve noise to mask surface noise.

As you say. if the volume is not cranked up, a lot of noise will be inaudible.

LOMC is inherently noisier than optical because far more gain has to be used.

I was so surprised by the residual hiss when I auditioned a Holbo system with a LOMC cartridge when it was not playing that I went back to see what the cause was.  It was somewhere in the amplification chain. The records I took in sounded very clean and have improved significantly with the DS Audio optical cartridge.

@richardbrand you nailed it. However…surface noise between tracks varies based upon the quality and condition of vinyl pressing. I have a few really quiet vinyl pressings where you barely hear anything between tracks at a normal volume level but it’s never completely silent. How much of that noise you hear also depends on a phono stage. In example of the tubed Melto2 that produces zero tube rush and is dead silent when Idle, it reproduces a good degree more of the surface noise than the Whest, using the same Hana Umami Blue cartridge. The surface noise is more audible with the Melto2 when playing an actual track, not just on dead wax. It’s not terrible and doesn’t bother me much on VG+ and higher grade vinyl. 
If you introduce a really high quality SUT to your LOMC cartridge to perform the gain duties it may potentially result in lower surface noise as a final product but it will never be completely gone. 
I believe what @oberoniaomnia heard and thought was a tube hiss was actually surface noise, and potentially a combination of surface noise and tube rush. 

As to the overall noise floor of a system at idle, if you have very efficient speakers and somewhat “noisy” electronics you will hear hiss at idle. In my system it’s nonexistent with my DAC selected as input on my integrated and there’s only a slight hiss with the phono stage when volume on the amp is set to 82 and above. My typical listening is done with volume between 55 and 75 on the amp. 
My speakers are 87db efficient. High quality modern solid state and tube gear is extremely quiet with virtually no noise floor but it will faithfully reproduce noise from a vinyl record.

OP…I didn’t mean to high jack this thread…sorry

@oberoniaomnia 

Reference? Amount of delta T? Duration? Pressure yes, and that leads to bubble formation. Bubbles are NOT due to heat, but due to pressure change. Easy to demonstrate by taking room temperature water, start pulling vacuum. Soon enough it "boils" but not because of temperature but pressure. Particularly with water's high heat capacity, I'm skeptical about any temperature effect due to US. Not a physicist for sure. I have run US for half an hour at room temperature (for SEM specimen preps), and there is no perceptible temperature change after that amount of time.

When I mentioned localized heat, I am referring to the heat generated by the collapsing bubbles on a micro scale. The energy released during the collapse of a single cavitation bubble can be quite substantial (several thousand degrees C), and when numerous bubbles collapse simultaneously, it can lead to a significant increase in the local (micro scale) temperature.  Just do an online search and you can find many articles discussing this. Here is a good review article:

"A correlation between cavitation bubble temperature, sonoluminescence and interfacial chemistry – A minireview"  published in the journal Ultrasonics Sonochemistry (Volume 85, May 2022) by Nor Saadah M. Yusof, Muthupandian Ashokkumar, and colleagues

Interesting re that U-shape curve. Reference? Scale? Whether U shape has maximum at 100 and minimum at 99 or 10 makes a difference, and determines whether it matters in practical applications. And, it will also depend on the specific compound, so assessment of a variety of them to see common pattern and variance will be important for proper consideration.

This effect is common knowledge in the scientific community. This effect is often used in industrial applications to minimize the amount of surfactant required. The degree of change in the CMC as a function of temperature  is dependent on the particular surfactant and the difference can be as large as a factor of 2. Many references only have an abstract unless you have a subscription. Here is one reference where you can read the whole article without a subscription.

Chen, Li-Jen. “Temperature Dependence of Critical Micelle Concentration of Polyoxyethylenated Non-Ionic Surfactants.” Colloids and Surfaces A: Physicochemical and Engineering Aspects, Elsevier BV, 1998.