Stylus hears adjacent grooves

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Using a Music Hall MMF-7 fairly high end turntable with a low-output moving coil GoldRing Eroica cartridge. Going through a NAD outboard phono stage with a setting for Moving Coil.
Good sound but maybe not as good as I recall from a low-output Moving Coil denon cartridge I used to have.

Question is:
I have never heard this before. I am hearing the adjacent groove! This is easily noticeable at high volume just before the music starts, but it also happens at end of record and during silences in the music itself. Most annoying is to hear Opera, with dead silence punctuated by soprano at loud volume. You hear her coming, singing, then going. Seems to happen on about all kinds of vinyl.

Has anyone else heard this? I put the same records on a cheapo turntable/catridge and there is no adjacent groove issue.

thanks!
 

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You are hearing pre and post echo on the record groove. It has the do with the mastering of the record and how close the grooves are spaced. If the grooves are cut too close together a loud signal from the adjacent groove can affect the groove before or after it, especially if the signal is significantly lower in those grooves such as silence. There is always some level of pre and post echo in every record groove but usually it is so low that it's inaudible. Highend record makers tend to space their grooves a little wider but this shortens the length of time available per side. Higher quality lacquer or direct metal mastering also produces less echo due to decreased elasticity of the master. If you are hearing echo then atleast you know your turntable has high enough resolution to pick up the echo.
 
There is print through from analog tapes as well but that is a separate phenomenon. You can hear groove echo from digitally recorded masters also. If you listen to pre echo and time it, it will correspond to exactly one revolution of the record.


excerpt from http://www.resolutionmag.com/pdfs/KNOWHOW/VINYLA~1.PDF


DMM, Neumann and Teldec
DMM, Direct Metal Mastering, is a cutting system that replaces the lacquer with a
disc comprising high purity copper plating on a steel substrate. It was a spin-off
from long running R&D by Teldec (Telefunken/Decca) into a video disc system who
found that the post cutting ‘relaxation’ effect of lacquer caused the loss of short
wavelength video information. Cutting into copper prevented this effect, and
although the video system wasn’t a great success, the benefits of copper cutting were
later developed for audio discs. Teldec licensed the system in 1980 and Neumann
produced practical systems in the form of a modified lathe and cutter head – the
VMS82 and SX84 – the very last disc cutting products they manufactured.
Aside from having no relaxation effect, DMM virtually eliminates pre and post
groove echo, and removes the need and costs for the silvering process at the start
of the pressing process, as well as its potential to add noise. The VMS82 lathe
required a more powerful drive motor while the cutter head has to address several
mechanical issues regarding cutting angle and the fact that the stylus is not heated.
Teldec had a strong engineering team and worked closely with Neumann from the
1960s. The original Neumann stereo cutting heads had been designed by Teldec,
were tested at Decca in London, and were then manufactured and sold by Neumann.
The VMS80, Neumann’s first lathe that wasn’t a direct descendent from the original
AM31 design of 1931, resulted from Teldec’s video disc development applied to
Neumann lathe design. Teldec and Neumann also collaborated on a piezo-electric CD
cutter that would allow CDs to be mechanically cut into copper, which worked, was
demonstrated, but was never developed into a full product.
Neumann
 
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Hmmm. If the pre-echo corresponds to one revolution of the record, then that's incontravertible evidence. But why isn't it distorted? I'd have thought you could only get that if one groove managed to overlap another? Are you suggesting a more subtle mechanism?

You added the answer to my question as I asked it. What a shame Teldec/Neumann didn't see fit to add a little more technical detail.
 
As I understand it tkwou is correct. Both phenomenon occur. I once read an explanation that said that the cooling of the disc after it leaves the press caused this effect to occur. The vinyl doesn't cool uniformally or something and, as already said, thin spacing allows a deformation of the adjacent groove...
 
You say you don't get this effect with a different TT and cartridge combination. Perhaps it is in part due to the profile of the Goldring Stylus tracing part of the groove wall that the other stylus does not, and resolving some vinyl print-through?

WRT the replies above, I have heard both analogue tape print-through and vinyl groove print through on certain (though thankfully not all, by a long way) LP's.

For example, my copy of Kate Bush's Hounds Of Love has a cutting error on Side 2 track 1 where there is a brief but noticeable breakthrough of vocal (no, it's not intentional, I checked on the CD...), whereas Mike Oldfield's Incantations suffers tape print through on Side 2, as confirmed by the CD issue.
 
You say you don't get this effect with a different TT and cartridge combination. Perhaps it is in part due to the profile of the Goldring Stylus tracing part of the groove wall that the other stylus does not, and resolving some vinyl print-through?


I purchased a Sumiko Black Pearl with a .5 mil stylus specifically to see if it would get below this phenomenon by falling down into the groove where there is thicker material between adjacent grooves.

The problem does go away.

But, the problem I was trying to solve with the Sumiko is referred to as "punch through" as I recall. This problem was much more severe than what sounds like tape print through (and evidently isn't in your situation, because it corresponds to the rpm of the record.)

What you are hearing may be a mild form of punch through (as has been stated) that is so slight that is doesn't have the usual coarse distorted sound.

The pitch screws on lathes either get worn or out of adjustment. This may be the cause of this problem. A slight mis-adjustment and it sounds like tape print through. It can get so bad that it simply makes a ripping noise.


This may be what is going on..... Groove echo is a very slight case of punch through....Or what will become punch through if it goes far enough.

The groove depth and spacing is controlled by computers in later years. Possibly the cutting computers needed periodic adjustment. Possibly the cutting engineer could make personal adjustments if he was trying to get an extra few minutes for a long classical master, and he pushed it to the limit.

While on this topic, does anyone know what "stitching" is? Is this the name for the ripping sound of a totally defective segment of a groove. You can see this problem in a record if held in the light just right. Little lines about one or two inches long in the grooves. Or is this "pull off" where some of the vinyl is ripped away by a dirty stamper?

The .5 mil tip doesn't help this problem at all.
 
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A little more detail.

Bob Ludwig's explanation is very informative. However, without explanation, it is a little misleading to simply say:

"The RIAA recording curve is designed to greatly diminish the bass frequencies so, while recording, the bass wiggles take up 400 times less room than they would without the curve."

Vinyl is cut substantially constant physical amplitude with frequency, and the bulk of the RIAA curve compensates for the fact that the cutting head and replay cartridge are velocity transducers. If we used an amplitude transducer for replay (such as the Euphonics strain gauge cartridge, or a piezo cartridge), we should only need a shelf equaliser with 318us and 75us time constants.* On replay, that shelf equalisation reduces the amplitude of bass frequencies below 500Hz by a constant 12.5dB compared to frequencies above 2.1kHz.

Does this mean that bass is cut with a larger physical amplitude than treble? No. What it means is that the RIAA time constants were chosen to match the typical spectrum of music at that time so as to require an equal groove width for all recorded frequencies. Music has changed since the early 50s, and "drum and bass" has a rather different spectrum. Note that such material tends to be released on 12" 45 rpm singles that allow a far greater groove pitch.



* In practice, strain gauge and piezo transducers incorporated the 318, 75 equalisation mechanically so that the following amplifier needed no electrical equalisation whatsoever.
 
Vinyl is cut substantially constant physical amplitude with frequency

You are veering into territory that I have never really gotten totally straight.

Isn't there a "turnover frequency" at 500 Hz that is the changeover from constant amplitude to constant velocity (or vica versa)?

the RIAA time constants were chosen to match the typical spectrum of music at that time

I don't follow you here. Are you talking about the frequency resonse of the old equipment?

The time constants are the poles of the RIAA filtering aren't they? What do you mean by spectrum of music? There is only so much room for deflection with a microgroove. It was 1-mil corss-section before stereo and .7 for stereo. The AES did the standardization work throughtout the years of the LP which began in 1948. I recall that the 78s had a curve (actually many curves for diff manuf as was the case with the LP until 1954 when the RIAA curve was adopted) that was somewhat similar to the LP curve but a curve was not utilized on playback.

equal groove width for all recorded frequencies

This is what the whole curve as about isn't it? Mabey it isn't. there were over ten curves in the early years of the LP. I recall that the RCA Orthophonic curve was what became the RIAA curve. But, they were all similar with somewhat minor variations.


piezo transducers incorporated the 318, 75 equalisation mechanically

They are close, but it is not exact. There is a midrange peak. There is also the problem of severe mechanical resonance in the carts.

Please elaborate on what you are saying, especially about todays 45 RPMs. Are you saying that they use a different recording characteristic? Or are they just boosting the bass to shake the floor?
 
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hailteflon said:
Isn't there a "turnover frequency" at 500 Hz that is the changeover from constant amplitude to constant velocity (or vice versa)?

Now I've seen people saying that too, usually in a discussion that includes cutting heads. I think the statement comes about because the cutting head is not ideal. But if you look at it from the point of view of the replay transducer (the cartridge), and assume that the cartridge is a perfect transducer, then:

E = n d(phi)/dt

In other words, the EMF produced is proportional to the rate of change of flux; double the frequency (or rate of change) and you double the EMF. Thus, the cartridge has a response that rises at 6dB/octave. To compensate for that, you need an electrical response that falls at 6dB/octave. And that's substantially what the RIAA replay curve is.

Now, the transition from 318us (500Hz) to 75us (2.2kHz) is rather more than two octaves, so I suppose you could argue that from 500Hz up to 2kHz, the record is recorded constant velocity. But if you do that, you have to say that it returns to constant physical amplitude after 2kHz, which seems rather messy. I think it's better to understand it as being constant physical amplitude with record pre-emphasis and replay de-emphasis to give noise reduction.

What I mean by "the spectrum of music at that time" is a graph of amplitude against frequency of live music (the sort of display you'd see if you used a Real Time Analyser on music). As you've said, before the 50s there was a plethora of different equalisation characteristics, and the problem was to decide which gave the best noise reduction without requiring excessive groove amplitude. That means you'd need to know if typical music had a lot of energy at one particular frequency, so you wouldn't want to boost that frequency too much. Trouble is, pop music has changed since the 50s, so the implicit assumptions made by choosing the RIAA curve are no longer valid for stuff like drum 'n' bass or electronic music. But if you have a 12" single and only intend to put ten minutes of recording on it, you can cut with a wider pitch between adjacent grooves than if you're trying to record twenty minutes, thereby allowing the groove to be cut with a larger physical amplitude (still using RIAA time constants).

As you say, piezo cartridges were hardly perfect, and their "equalisation" would have been less than ideal. I don't think the loudspeaker in a Dansette was too good either.

Hope that helps.
 
The one exception to piezo is the old Microacoustics. The compliance to RIAA was done by a thick-film RC network built into the cartridge rather than counting on the cartridge's internal mechanical resonances.

It's a pity that they couldn't market that cartridge with its own dedicated preamp, which would have really taken noise down to a minimum, but audiophiles hate it when someone does things right without their interference.
 
Trouble is, pop music has changed since the 50s,


So has microphone technology.

Regarding 45 rpm: The linear velocity of the 33 at the minimum distance from the spindal is the limiting factor in the geometry. The standards are all centered around the maximum stylus deflection at maximum frequency above which the cutting stylus sees a backwards motion of the lacquer. The .7 mil conical is just small enough to fit into a 20HKz curvature at minimum distance from the lable. There is also the problem of narrowing of the groove as velocity increases(pinch effect)---enter the elliptical stylus.


Angel 45s advertized essentially what you are saying. Higher linear velocity meant greater amplitudes, but the RIAA curve is still used because of the nature of velocity oriented transducters, mag carts.

Interesting what you said about the 500Hz crossover. I recall seeing that the depicted curve in standard literature is actually not the real curve. The 318 and 75 constants actually cause some little wiggle somwhere that is conveniently filtered out of the graph with a pencil.

Most of the albums of 50s and 60s informed the owner of the 500Hz crossover frequency on the back of the album, like everyone knew what it was.
 
audiophiles hate it when someone does things right without their interference.

MA had a good thing going. I recall a noted audio editor of the period railing against MA because they were changing the word "piezo" to whatever they called their generator. What is an "electret."

Audiophile vinyl is a tough game to win. I have just recently learned (almost sure about this at this point) that Mobil Fidelity is all digital remasters. All the way back to 1977.

Direct to Disc are all digital unless there is no pitch control used in the cutting process. Can't have a preview signal without a tape.

Many of the standard commercial issues were excellent if one gets a good pressing. Most any record after about 1981 is digital whether it says it or not. It isn't a "remaster", it is cut using a digital delay line.

Columbia Half-Speeds are real analog as are RCA half-speeds. PCM digital was used in 1972 on Denon records.

The notorious Weathers cartridge of the 50s had its own preamp. People get tired of something quick when it costs more money and is somewhat of a niusance. It develops a commercial mind-set that is difficult to overcome.
 
Stylus hears adjacent groove

Hi hailteflon, about reading adjacent groove, i have my tt doing it since i use a surgical silk belt. Nothing changed in cart align. About stitching i had recently a newsletter from classic records that says they had this problem with their first 200 g pressings. Cannot check now but will do and report.
 
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