No trolling, but it really seems you're missing the point of this thread. It's really the pursuit of vinyl par excellence. Or unfettered curiosity to understand what exactly it takes. Not convenience, not other metrics that could otherwise be considered worthwhile. At the same time is it not filled with flights of fancy or nonsense, even if strong opinions are offered.
So, no, you're not injecting common sense. That baseline is was established right from the get-go.
A brand new vinyl album is silent.
I get the feeling that not too many here are not buying new albums, preferring to scour junk shops.
If the run up and between tracks are noisy on a well cleaned used album the damage is permanent and is caused by a bad stylus etc.
Not all music lovers were particularly bothered about caring for their equipment or how much they spent on it so it's a lottery when buying used discs.
Old, noisy discs can be digitized and the artifacts made less annoying, which is great for rare recordings.
The originator of this thread wanted to know how to remove the between track noise, and it was never answered, other than play the disc wet!
Well, so far those files haven't been posted or PM'd. So we are left with Hans' graphic plots only to try to analyse as best we can, which is not so good because the one-off FFT parameters lead to compromises in resolution and noise, neither of which is as good as having the files.
Still, I spent a happy hour or so attempting to reconcile what might be going on just by looking at the plots, and here's what I found.
AFAIK Hans suggested he'd used an Adjust+ test record, for silent groove. According to the track listing for that test record, there is only one silent groove, so I don't understand how it's possible to measure noise floor for inner and outer tracks using that record ?
I looked first for reduction in amplitude of the cart-arm resonance at c 10Hz, which is the usual marker for reduction in friction IME. Whereas the outer track plot might suggest some reduction between wet-dry, perhaps c 6-8dB, this is absent from the inner track measurement. It's difficult to say because of resolution, but overall there isn't conclusive evidence that friction was successfully reduced IMO. I've never known wet playback not to reduce friction coefficient, nor reduce amplitude of cart-arm resonance, over years of testing, I should say, so this seems odd.
Reasonably, if one visually places a line of fit through the (noisy) spectrum plots, for the outer track there are notable differences between wet/dry playback spectra, amounting to 3-6dB difference in noise floor for wet playback versus dry, except at the octave around 1kHz. However, the wet playback spectrum plotshows the noise floor to be elevated for wet playback, ie it is noisier, above 1kHz !! Yet suppressed, quieter, below 1kHz. But only for the outer track. Again, I find this odd, and I've not seen anything like it in years of testing. The inner track plots show no notable difference between wet/dry spectra, which again is odd IME.
So, I disagree with Hans as to whether any conclusion can be made from his test. Unfortunately, I am sure something very odd is going on with measurement or analysis, because IMO there is no sense to the result. I think the raw files would be revealing, if they can be made available?
Also, at risk of being tedious, I still can't find documented the spec level for the 1kHz test tone on the adjust+ record, so unless used with the provided software suite, strictly we can't really comment on S/N ratio in absolute terms IMO.
LD
So we were waiting for each other.
Your posting with "it's a deal" gave the impression that you were referring to the raw recorded files of my measurements with your still not announced test disc.
Now it seems you were expecting raw files from my previous recordings. Which recordings did you mean btw, I published several of them.
However I made jpg's of all recordings without ever keeping the original raw data, this only consumes many MB's of disk space without giving me anything in return.
Compromises in resolution and noise ? The plots are the direct outputs of my recording system, nothing compromised, neither in resolution nor in noise. Resolution is 1.5Hz, much better than what you have ever published and resolution lies ten's of dB's under the recorded LP noise. Just as with the sidelobes from the 1Khz tone that you interpreted as signal, I'm getting the impression that FFT's are not your world.
Ask and you will get an answer. Your comment possibly suggests that I was doing ....?
To start with, the silent track on the record is too short for averaging 32 FFT's.
But after almost every test on the disk, the groove ends in a loop.
These are the ones that I used for testing the outer track and inner track.
The 0dB 1Khz track however is long enough for the recording of 32 FFT's and shows the same L.F. noise level confirming that the loop is a good point to test the LF noise of a silent track, but I'm almost sure you won't agree.
Only at 10Hz to be precise.
This is what the whole discussion concerns.
If you want to make your point, show graphically what you mean, which is what I did. I projected the outer track wet and dry on top of each other. This leave little from what you say. As you can see, apart from a bit more noise at 10Hz, there is no significant difference between wet/dry on the outer track up to 3Khz. From thereon the Right track in red stays the same in level but the left track in blue differs gradually up to +6dB in amplitude at 10Khz when playing wet.
Since left and right do not perform identically, you cannot tell whether this has any significance. So your above comment is suggestive but incorrect.
At the same time the left and right channel of my cart are not behaving identically, reinforcing the suggestion that when playing wet, one channel reacts more aggressively to wading through water.
This is the point that was mentioned before, you are biased in your thinking and not accepting anything else but your vision. You even doubt whether 0dB on a test disc is really 0dB. I regard the skills of dr Feickert to be on the level of German perfection, but I'm still not sure how to estimate your skills.
And why you are so secretly about the test disk that started all this, is even a bigger mystery. That would make things directly comparable, but for some reason you seem to avoid this step.
Hans
P.S. I already called this discussion a dead end street, but up to the point where I can repeat the test that you published, I won't respond anymore.
Last edited:
I'm sorry we all can't agree here. I have one comment, Hans, a log frequency plot that starts at 10Hz is not very good for showing the low frequency resonance at 10Hz. The FFT is inherently linear so the resolution varies widely across a log plot. George and I have posted some plots with very long FFT's that make the low frequency behavior much clearer.
BTW I think there might have been a misconception concerning cutter head cooling. Neumman used helium but as a gas instead of air because it has 5X the specific heat capacity. Someone said they used liquid nitrogen IIRC. The heads run at 200C max.
http://www.vintagewindings.com/gen pop/8299543VW8335/NeumannVMS/Neumann-SX-74.pdf
Last edited:
Hi Scott,
I accept your comment that my plots are not meant to be used for detailed analysis around 10Hz, although the FFT starts at 1.5Hz with a resolution of 1.5Hz. I could have also displayed a linear plot from 1.5Hz to 30Hz, and as a matter of fact I can simply redo this if you like.
But showing just the results around 10Hz was never the intention. Please keep in mind that the discussion started with LD's posting #29 showing a spectrum from 100 - 2500 Hz with great differences in noise between dry and wet.
My comment on that was that I had the same sort of noise dry as he recorded wet.
My recordings to compare were showing the results for a much wider spectrum going from 10Hz to 10kHz, without any significant differences between dry and wet.
And in between I showed a linear plot from 1Hz to 35Hz in posting #59.
That may be the kind of plot that you refer to. This was a frequency response plot, not a noise plot.
Since the subject of this thread is finding possible ways to Reducing Record Surface Noise, everything below 20Hz does not influence the perceived noise from the reproduction chain, however it influences the IM distortion as shown in my posting #85, but that's not the subject here.
So the region around 10Hz might definitely be another interesting area for finding ways to reduce IM distorting. May be an idea for another thread ?
Hans
No it isn't. There is a measurable noise floor as posted by Hans.
ooh double negative. I don't think you meant what you trolled.
Right, but it is difficult to separate AM and FM sidebands when one looks at the widening of the fundamental tone. I did some 960000 point FFT's on 96k recordings and could easily see the .55Hz rotational sidebands which are predominantly FM/PM.
Sorry about the double negative, I've been watching too much Brit TV on film on tv uk. We are finding it very hard not to use ANYTHINK and NOTHINK. 😉
Recording a silent groove does seen rather a waste of time, why not something useful, like mice farting? David Attenborough would find it interesting and it could be a Youtube hit.
Noise never worried the audio buying public back in the 70's when hifi mags convinced everyone they needed a cassette player.
well UK magazines had plenty of articles on noise and vinyl, with analysis. The late John Crabbe is much missed in that respect as is the shure V15 cartridge. Come 1974 and the oil crisis vinyl quality went badly down hill from the majors and that was noted in print as well. So really not sure what you point is. But as since 12th October your only posts on this forum have been in this thread and all unhelpful I can only conclude that you are the sort of person the ignore list was made for.
Stay away from personal comments and get back on topic.
Wouldn't lead out groove let us make infinite measurement with regards to time ? Since we are only interested in surface noise measurement we can take two different vinyl one heavily used and one brand new. Heavily used can be measured dry and brand new wet so as to make the measurements distinguishable by extreme results.
Last edited:
Scott, you raised the issue of looking at around 10Hz.
Of all the recordings dry/wet that I made, I happened to have saved just one original recording, being the one played wet on the outer track, the graph at the upper corner right in posting #122.
This recording could therefore be newly drawn in a logarithmic way, starting at 0Hz and also in a linear way.
Both are attached below, the logarithmic going to 1Khz an the linear one to 60Hz.
Was this what you meant, and which of the two do you prefer in that case.
I could make a new set of recordings displayed in this way.
Hans
P.S. And just a question, isn't the superimposed AM from the resonance frequency resulting in IM distortion ?
Of all the recordings dry/wet that I made, I happened to have saved just one original recording, being the one played wet on the outer track, the graph at the upper corner right in posting #122.
This recording could therefore be newly drawn in a logarithmic way, starting at 0Hz and also in a linear way.
Both are attached below, the logarithmic going to 1Khz an the linear one to 60Hz.
Was this what you meant, and which of the two do you prefer in that case.
I could make a new set of recordings displayed in this way.
Hans
P.S. And just a question, isn't the superimposed AM from the resonance frequency resulting in IM distortion ?
Last edited:
So we will never be able to repeat your analysis, nor run our own, nor explore variously different elements to examine why the odd results. This is a pity and poor method IMO, but hey so be it. If there is a mistake we will never find it now.
Strangely, I have similar suspicion about your analysis, Hans 🙄
....a locked groove is not a continuous random sample, not only does it repeat, but there is a significant event at the lock location, especially on silent grooves. Further we do not know that run out grooves are ever intentionally truly silent, strictly.
LF spectrum can be examined on any and every vinyl recording, no matter what programme material. It's part of the vinyl signature, and is a useful marker for cart-arm stability and friction. However, for whatever reason, your plots don't resolve the typical lf signature, nor extend below 10Hz. If you had kept the raw files, we could have analysed properly. Now all we have is a few points at low resolution, and can only guess which leads to no sense and contradiction between the inner and outer test results.
Method is everything.
....but in the direction that playing wet INCREASES noise by up to c 6dB !! Which is nonsense, frankly, and isn't repeated for your inner track result.
My opinion is that we cannot tell whether any of this has any significance. Since we can't analyse the raw recorded files for ourselves, personally I feel the best way to reconcile with past results is to safely ignore it. No doubt it is well intended, but results aren't even self-consistent, and can't be reviewed.
Perhaps you can point to where in the test record documentation 0dB absolute reference level is defined, that will be fine. I looked reasonably, but can't find it. So, strictly, I consider we don't know. There is more than one 0dB reference level in use. I have Decca, NEC, Shure and JVC test records with reference levels that differ from your assumption, Hans.
Then if we don't strictly know the absolute 0dB level on your test record, and aren't confident of the noise floor measurement method, there's no reason to be confident in much at all from your test, in absolute terms or even relative terms, I think.
Because it doesn't matter. The plot I posted shows a clear improvement to noise floor in relative terms, between wet and dry playback, whilst programme level remained unaltered. As it happens, I used an EMI in-house factory test record which has one whole side pressed with IMD test tones, because I have several copies of this record and could afford to ruin one.
IIRC the 3rd party recordings I have were made with a VOX test record with a 3kHz pilot tone.
I don't think there is anything more to say, Hans. Unfortunately, there is no way to verify or further analyse your result either.
LD
Hi Grasso,
Those were wise words.
I'm sorry I contributed to this noise with sadly enough no result.
Hans
As long as the LF is resolved either would suffice, another 4X or so would fully resolve the peak. It's not just IM that I'm talking about since the system is not rigid both amplitude and phase would intermodulate in the worst case.
An interesting math exercise might be to correlate the LF activity to the sidebands on a 3k or 1k reference tone. I have a lot of raw files around but none wet played.
BTW I gave Jan some in-amps for you, I though you might try a G = 100 head amp some time to compare noise/sound.
A few years back I collected together what few 3rd party recordings of wet versus dry play there are to be found on the web. So I have a few, plus my own of course.
I just picked one at random from my 3rd party wet-v-dry collection; it's a recording of the opening of Fanfare For The Common Man, nice bit of Copland. Reduction in surface noise is obvious to the common man (!) by listening.
A few minutes ago I ran LF analysis on the wet -v - dry recordings of that 3rd party Fanfare for the Common Man, starting at exactly the same location.
The LF spectrum plot is attached below. There's about a c 12dB reduction in amplitude of the cart-arm resonant response in favour of wet playback. This is thoroughly typical IME, and reconfirms my own results and those of 3rd parties. There can be no doubt of this phenomenum.
I believe it is explained by reduced stimulus for headshell movement in the case of lower friction from wet playback. Variation in friction = variation in skate force = stimulus for headshell motion.
Surface noise aside, the audible improvement from improved headshell stability comes from improved pitch stability, ie reduced FM vibrato. The 10Hz resonance physically moves the headshell, so stylus very slightly speeds up and slows down which results in FM.
Though there is huge c 10Hz baseband signal transponded by the cartridge, this does not amplitude modulate signal - rather it is simply superposed. So one does not see artifacts of AM modulation - rather those of FM.
I believe this is how adjust+ looks at pitch stability, BTW, by FM demodulating a tone of a few kHz. What not many people know is that headshell movement due to cart-arm resonance is THE single biggest contributor to pitch instability after eccentricity/warp IME.
I wrote my own FM demodulator to look at pitch stability using a similar method a few years back, just for my own use and fun.
What Hans should have seen in his LF spectrum was a significant difference in resonant amplitude between wet and dry playback. Though his analysis doesn't permit proper examination of this phenemenum, what there is does not suggest he was successful in reducing friction between wet and dry cases, for whatever reason.
Here's the Fanfare For The Common Man wet-v-dry spectra in good resolution. If anyone wants a link to the raw audio files, PM me. They were recorded by a 3rd party, and are clearly audibly different as to noise.
LD
