Wet playing revisited

[Ldg]

Thanks fellow enquirers !

[Ldg]

Here's a full spectrum plot of pink noise 10kHz spectrum wet -v- dry, repeated for three tests. The plot inevitably has a fair amount of noise itself, and is obscured a bit by overlay results and so isn't the most useful, but i think indicates there's probably no significant spectral difference for pink noise up to 10kHz - at least in this test. The lf response is as discussed previously, significant differences possibly due to reduced noise floor (or ticks/pop energy). Ortofon 2M Red in Pro-ject 9.6C arm.

[chalmh]

ld,

A wonderful work.

Keep in mind that deterioration in noise would be most significant at the first plays and possibly behaves exponentially. Wear of the vinyl is probably not linear and we know it from the dry playing experience. The first play makes the most damage by affecting the high frequencies.

I may assume that all those who were listening wet for years and say that the record was damaged is because the possible lack to clean the record well prior every wettening (which is a torture to do it frequently). If the record is cleaned well every time, it will keep performing well all along for many years.

[flavio81]

ld, what fluid are you using?

The curves are impressive.

[Ldg]

Hi flavio81,

I use 3:1 distilled water:isopropyl alcohol (lab grade) plus 1 drop per litre surfactant (colourless dishwasher rinse aid). Stored in glass containers. Afterward I rinse with distilled water.

[flavio81]

Hi flavio81,

I use 3:1 distilled water:isopropyl alcohol (lab grade) plus 1 drop per litre surfactant (colourless dishwasher rinse aid). Stored in glass containers. Afterward I rinse with distilled water.

Does it evaporate too quickly? (i.e. you need to reapply the liquid half-way during playback of an entire side)

[missan]

Hi ld
Looking at Your latest plots of dry play, there is a certain level at, and around the res. freq. If this level was lower with another combination of stylus/cartridge/tonearm, one explanation would then be that the damping could be different, thus the lower level.

I´m not totally sure what I´m getting at, but one explanation could still be that the phenomina is some type of damping? I mean these very low stylus velocities that affects and lowering the noice, they could be lowered both by amplitude reduction and dampening microscopic vibrations?

sorry for rambling
missan

[Ldg]

Hi flavio81,

I use 3:1 distilled water:isopropyl alcohol (lab grade) plus 1 drop per litre surfactant (colourless dishwasher rinse aid). Stored in glass containers. Afterward I rinse with distilled water.

Does it evaporate too quickly? (i.e. you need to reapply the liquid half-way during playback of an entire side)

Yes it does evaporate quickly, and only just lasts one side because I use a lot of fluid. I think perhaps distilled water + surfactant alone is also OK, but this is what I use for now.

[chalmh]

Let me elaborate my assumption why the lower frequency noise is more attenuated during wet playing.

We need to keep in mind that the groove and the stylus are "micronic". The stylus profile is very identical to the stylus cut. Adding a liquid into the microgroove while the stylus is in causes a "Lateral meniscus" between the groove walls and the stylus outer surface. That "Lateral meniscus" mechanism is providing two element parameters. One - adhesion between the two surfaces. Two - a "bumper" and shock absorbing ability. Both elements are attenuating the cantilever from "ringing" in the arm self resonance frequency. This attenuates the resonance amplitude and reduces the low frequency intermodulation with other lower frequencies.

While the arm is "ringing" during the dry playing it is the arm inertia to compress the cantilever into the groove and increase the "rubbing" noise of the vinyl groove with the stylus because there is no "Lateral meniscus" between them.

[Ldg]

Hi ld
Looking at Your latest plots of dry play, there is a certain level at, and around the res. freq. If this level was lower with another combination of stylus/cartridge/tonearm, one explanation would then be that the damping could be different, thus the lower level.

I´m not totally sure what I´m getting at, but one explanation could still be that the phenomina is some type of damping? I mean these very low stylus velocities that affects and lowering the noice, they could be lowered both by amplitude reduction and dampening microscopic vibrations?

sorry for rambling
missan

Explaining what is going on is very interesting and challenging. Here's some of my own ramblings, missan !

I do not know either if there is any significant damping going on. Sometimes I think yes, because fluid drag would be velocity sensitive and have the correct form. Sometimes I think no, because the Q of the lf response seems to remain the same. I cannot think of another test other than the Q measurement.........?

I think Thomas_A has several good points:

Firstly reduced ticks and pops might provide less stimulus for resonant behaviour. Ticks/pops are impulses, and have wideband energy, including lf, but the reduction is very large......too large methinks for this alone to be the explanation perhaps ?

Secondly, significantly reduced friction might account for reduced noise floor energy. I previously measured a reduction of c 30% in friction coefficient IIRC, wet -v- dry. That is significant, and might be related to noise floor reduction i think. It also seems possible that the lf response is simply part of reduced noise floor through friction. Lastly, the pink noise plot shows the reduction in lf response persists in the presence of broadband signal level much higher than the noise floor, so that behaviour seems unrelated to audio band energy.

[chalmh]

ld wrote:

Yes it does evaporate quickly, and only just lasts one side because I use a lot of fluid. I think perhaps distilled water + surfactant alone is also OK, but this is what I use for now.

You are right. I'm also avoiding the IPA and use the filtered water and the colourless dishwasher rinse aid. Even so I'm experincing wettening twice one LP side due to the evaporation. There is another "problem". The liquid at the inner area is moving towards the outer edge while the record is turning (centrifugal foce) so the second attempt to wetten is the inner tracks.

[Ldg]

Let me elaborate my assumption why the lower frequency noise is more attenuated during wet playing.

We need to keep in mind that the groove and the stylus are "micronic". The stylus profile is very identical to the stylus cut. Adding a liquid into the microgroove while the stylus is in causes a "Lateral meniscus" between the groove walls and the stylus outer surface. That "Lateral meniscus" mechanism is providing two element parameters. One - adhesion between the two surfaces. Two - a "bumper" and shock absorbing ability. Both elements are attenuating the cantilever from "ringing" in the arm self resonance frequency. This attenuates the resonance amplitude and reduces the low frequency intermodulation with other lower frequencies.

While the arm is "ringing" during the dry playing it is the arm inertia to compress the cantilever into the groove and increase the "rubbing" noise of the vinyl groove with the stylus because there is no "Lateral meniscus" between them.

Hi chalmh. Very interesting. Perhaps you might be right about a meniscus layer. I wonder if such a meniscus might fill in micro-defects in groove walls, and that is how the noise floor reduction comes about, also reduced friction ?

I'm less sure about such a meniscus providing mechanical buffering, because I think that would show up as increases in 2nd/3rd harmonic distortion plots, but it doesn't. 3rd harmonic distortion did appear to fall though................fluid doesn't compress much.............

Chalmh, I think what you said about lf explanation is the same as missan's damping effectively ?

[chalmh]

Let me make a simplifying analogy.

Using a bath tub full of water and float on the water a big can near a small peanut shell will cause the peanut shell to stick to the big can. When you look precisely at the touching edges of both you may see the "Meniscus". Now when you try to move slowly forth and back the big can, the peanut shell is folowing that movment as well. If the movement reaches to higher velocity the can and the peanut shell will separate.

Moving the can slowly - low frequency.
Moving the can fast - higher frequency.

But, that following of the peanut shell is a bit delayed due to its response time. The delayed "energy" will distort the water "meniscus" until both are moving together.

I hope it makes abit more clear what I think.

I think missan and me are saying the same but in different words. We need to keep in mind that all what we say here is just theoretical assumptions which are not yet fully proven. Intuitively, I think we are on the way to break a myth which the record and stylus companies will not like.

[missan]

More ramblings.
As ld has shown, there seems to be no level reduction dry/wet when playing notes or noice. Consequently there might be no lf reduction if these amplitudes come from "real" lf frequencies, like warps and such.

If looking closely at responses from scratches and ticks, the oscillating time is rather long depending on low damping coeff. of the suspensions. If this time is shortened by the fluid, could this affect the lf level? Or the level in general?
missan