Stylus hears adjacent grooves

[Mahadeva]

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!

[tkwou]

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.

[EC8010]

No, I don't think it's anything to do with groove spacing, it's tape print-through on the reel the LP was mastered from.

Where's Hobbes? (That is Calvin, isn't it?)

[tkwou]

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

[EC8010]

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.

[Jonathan Bright]

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...

[EC8010]

Whatever the cause, Mahadeva is entitled to feel smug that his turntable etc is good enough to resolve the problem.

[Jonathan Bright]

Sorry tkwou. I didn't mean to be redundant. I missed you #4. Must have gone up while I was typing.

[starfield]

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.

[hailteflon]

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.