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Why the huge difference in static from the start to end?

Posted: Sun Mar 03, 2019 3:34 pm
by larryh
I was just recording a Edison record of Spring Beautiful Spring by the Peerless Orchestra. The noise of the surface was very loud in the beginning. When I loaded it to the computer and checked the start and then the finishing portion I was almost shocked at how little surface noise was toward the end. Does it mean that when new the record had an almost silent surface but somehow over time the outer parts are much less quiet? I have experienced a lot of Edisons that one would think should be reasonable on surface noise only to be disappointed when playing it. The guess I have is that since Edisons shouldn't be cleaned with water that somehow over time they get moisture in the from the outside of the rim inward. I know I have purchased a few sets of black label records that today most would agree were or should be noisy. But they weren't. It seems that storage conditions most likely are the reason so many are prone to static noise.

Re: Why the huge difference in static from the start to end?

Posted: Sun Mar 03, 2019 3:42 pm
by barnettrp21122
I believe the surface noise volume difference is because of the change in circumference of the groove as it moves inward. The groove speed decreases, reducing surface noise volume, though the recorded frequencies remain at the same volume level. This happens with all records, I believe, although it's easily more apparent with Edison discs. True?
Bob

Re: Why the huge difference in static from the start to end?

Posted: Sun Mar 03, 2019 3:53 pm
by Wolfe
barnettrp21122 wrote:I believe the surface noise volume difference is because of the change in circumference of the groove as it moves inward. The groove speed decreases, reducing surface noise volume, though the recorded frequencies remain at the same volume level. This happens with all records, I believe, although it's easily more apparent with Edison discs. True?
Bob
Partly true. With lateral records there is a phenomenon called 'pinch effect' that can cause a slight loss of higher frequencies in the inner grooves. I'm not sure that vertically cut records should be so afflicted.

For the surface noise thing, I don't know. Could be several things, like maybe how the condensite varnish was applied. I don't think it's down to the decreasing groove velocity that the surface noise lessens. If anything, if that were true, the noise would lower in frequency and maybe be even more apparent on an acoustic machine

Re: Why the huge difference in static from the start to end?

Posted: Sun Mar 03, 2019 4:39 pm
by 52089
This is a characteristic of the war date pressings having to do with the materials that were substituted when the preferred materials could not be imported. As for why it's better as the record progresses, I would guess it has to do with the interaction of the diamond stylus as the linear speed decreases underneath it. Perhaps the higher linear speeds producer higher frequency noise, which is lessened at the record plays?

Re: Why the huge difference in static from the start to end?

Posted: Sun Mar 03, 2019 10:45 pm
by donniej
Things usually wear the most where people interact with them. Just like knobs and handles on machines, tn the case of records, this is at the lead in area, where the user drops the stylus.

There's also the constant trade off between surface speed for volume and the resulting surface noise. This would of course be most prominent at the outside edge. Since volume isn't much greater in this area, I think it's more likely that the user dropping the stylus haphazardly on the lead in area causes the excess noise.

Re: Why the huge difference in static from the start to end?

Posted: Mon Mar 04, 2019 3:55 am
by Orchorsol
Also with the large change in linear velocity from start to finish, groove noise is heard at progressively lower frequencies, with the psychoacoustic effect that it will appear to reduce more than it actually does in scientific terms.

Re: Why the huge difference in static from the start to end?

Posted: Mon Mar 04, 2019 4:56 am
by CarlosV
I experience the same effect as Larry reports, in most Edison records, irrespective of their issue period. To me the explanation is simple: in many instances the records were not played from beginning to end, leading to higher wear in the start. This happens with lateral cut 78s as well, their start being more worn than the rest - in that case reuse of worn needles was the main cause, but to a certain extent that would apply to Edison records as well - diamonds are NOT forever.

Re: Why the huge difference in static from the start to end?

Posted: Mon Mar 04, 2019 9:35 am
by larryh
Orchorsol wrote:Also with the large change in linear velocity from start to finish, groove noise is heard at progressively lower frequencies, with the psychoacoustic effect that it will appear to reduce more than it actually does in scientific terms.
Thanks for the opinion but in this case the ending portion sounded like a late electrical disc with almost no surface sound, but the start was exactly the opposite.

Re: Why the huge difference in static from the start to end?

Posted: Mon Mar 04, 2019 1:18 pm
by Wolfe
CarlosV wrote:I experience the same effect as Larry reports, in most Edison records, irrespective of their issue period. To me the explanation is simple: in many instances the records were not played from beginning to end, leading to higher wear in the start. This happens with lateral cut 78s as well, their start being more worn than the rest - in that case reuse of worn needles was the main cause, but to a certain extent that would apply to Edison records as well - diamonds are NOT forever.
More often attributed to a new steel needle shaping itelf to the groove dimensions at the start of the record.

Re: Why the huge difference in static from the start to end?

Posted: Mon Mar 04, 2019 8:23 pm
by Governor Flyball
Theory Number 6:

I have observed this effect as well. As only Edison discs appear to exhibit this problem, I wonder if it had anything to do with how the lacquer was applied and cured? Consider that the laquer was painted on and perhaps it was applied thicker in the center leading to the quieter surface?

I suspect a closer examination of the lacquer and comparison between the outer and inner surface may reveal why. I am also curious if the overall noise has escalated over the past 100 years.

I do not think the increased noise at the record start has anything to do with wear.