old vinyl "pre-echo" - why? Bruce? Anyone?

[nat whilk II]

Haven't had a turntable for years - just had one given to me so all the old vinyl is out of the closet and I'm having a lot of fun listening to the old stuff.

 

Question: on lots of old vinyl, just before the song starts, you can hear a very faint version of the song starting maybe 1 second or less before the actual, full-volume song kicks in.

 

Whyfore and what up with that?

 

Probably a question for Bruce, huh?

 

nat whilk ii

[blackpig]

Weird. But I've heard it on cassette tapes too.

[KB Gunn]

I believe you are describing analog tape print thru. It was most likely on the master that the records were cut from. As the tape wraps around the reel, there is a faint bleed into the next layer of tape, only noticeable when there is silence in the part of the tape that it bleeds to.

[franknputer]

It may be what is known as print-through. When analog tapes are stored, sometimes the information on one layer magnetizes the adjacent layer slightly, producing a faint echo. Master tapes are usually stored tails-out (i.e. not rewound) to minimize the effect. Thinner tape is more susceptible - that's why you hear it on cassettes, too.

[steadyb]

When an analog SIGNAL stored on MAGNETIC TAPE is partially transferred to the section of tape adjacent to it on a reel, the result is called print-through and is heard as a pre-echo. Thin tape, particularly when stored for a long time without being rewound or played, is highly susceptible to this problem. Storing tapes 'tail out' is recommended to minimize the effect of print-through. Also called signal transfer, or printing.

[steadyb]

curse you franknputer!!!

 

Yep. Ya beat me to it.

[franknputer]

Uh, yeah.

[nat whilk II]

that explains it! wow all you old guys are worth having around after all!

 

nat whilk ii

[The Soundman]

That's why they stored analog masters "tails out." This generally allowed any print through to be absorbed within the program material. (sometimes you could hear a slight echo during quiet passages) If the masters were stored "tail in" or in the completely rewound state, later (chronologically) passages would print through to earlier sections of a song, resulting in a very odd sounding pre- echo. This didn't stop Led Zeppelin from doing it on purpose in the song "Whole Lotta Love" which I thought was a pretty cool effect.

[lazaraga]

Originally posted by KB Gunn I believe you are describing analog tape print thru.

 

store 'em tails out!

 

my vinyl of chick corea's "return to forever" has the worst evidence of print through. really noticeable when you have alot of quiet/solo passages on an album.

 

peace

[KB Gunn]

Originally posted by steadyb curse you franknputer!!! Yep. Ya beat me to it.

 

FWIW, I beat ya both:cool:

[franknputer]

No you didn't - check the times. Both of us, 8:00.

 

You just got lucky, punk.

[KB Gunn]

yes they are the same time, but I pushed the send button first and am listed first. That counts in Jeopardy...

[KB Gunn]

Hey, this could be fun. Somebody post questions about antiquated subjects that only old geezers and gassers would know and see who answers first!

[boosh]

I think the record you have is cut from a mastertape that suffered from bleadthrough.

That's why sometimes they store tapes "Tails Out"

 

Does this help?

[Scodiddly]

The "tails out" thing is so that the tape is fed onto the storage reel with better tension control - it's supposed to be played, not fast-wound. Winding would result in higher wrapping tension, layers squeezed closer together, more print-through.

[franknputer]

Originally posted by KB Gunn yes they are the same time, but I pushed the send button first and am listed first. That counts in Jeopardy...

Forum bug.

[John Sayers]

The pre- echo tape problem is usually fixed by the mastering engineer adding leader tape to the master before cutting.

 

If I remember correctly - (I may be wrong) the cutter can cause pre-echo by having the lead-in groove too narrow causing the start of the track to bleed to the adjacent walls of the leadin groove causing a pre echo effect.

 

cheers

john

[KB Gunn]

Originally posted by franknputer Forum bug.

 

LOL!

[Anderton]

Since we're into tape trivia...

 

Another reason for playing through then storing, instead of winding, is that the "pancake" top and bottom are flat. When you wind, some layers of tape stick above or below the pancake, so if you pick it up incorrectly, you could push down on these and bend the tape. The odds of that happening are just about nil if you play through.

 

But all this talk reminds me of why I was soooo happy when the price of hard disk recording came down!

[steadyb]

Originally posted by KB Gunn yes they are the same time, but I pushed the send button first and am listed first. That counts in Jeopardy...

 

Well the print through of my post would've beat you both, but...

[Bruce Swedien]

OK Kiddies.....

 

The first condition you described has to do with phonograph records and is "Groove Echo".

 

Here's a great explanation by my old pal Bob Ludwig, the highly talented mastering engineer. I read this on the internet and was so impressed with his great explanation that I saved it!

 

Ghost In the Machine: groove echo in vinyl disks.

 

One of the great advantages of digital audio is that both vinyl records

and analog tape suffer from the transmission of sound from one recorded

layer of tape or record groove to the next. There is no cross-talk in

digital, it is only limited by the associated analog circuitry.

 

Groove echo, as it is called in the industry, is the result of a double

whammy. The first whammy occurs in the cutting process and the far worse

whammy occurs in the plating and even some in the pressing process.

 

When a groove is cut into a master acetate the grooves are purposely cut

as close to one another to maximize the recording time of the disk. 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. On a good lathe, each rotation

of the lathe will result in the newly recorded part of the groove just

touching the previous rotations engraving. On the last state-of-the-art

lathes with computers (starting from about 1978) the newly recorded part

of the groove actually nestles into the previous rotation! The sound

of the deformed plastic of one revolution is probably always measurable

in the next and on some occasions is audible.

 

A newly recorded acetate is a joy to listen to. It is far, far quieter

than the final pressing (no matter whose vinyl formulation is used), it

is totally free of ticks and pops (until you touch it) and the groove

echo is very low.

 

The acetate is almost a living thing. How a lacquer electroplates is a

function of how well cured the lacquer is. The amount of oils in the

acetate are a function of how the manufacturer made it, how long it was

cured at the plant, and how long it was allowed to acclimatize to the

cutting room environment before cutting. After cutting, time starts to

act on the blank and the groove echo begins to build up within the

master lacquer. The first 24 hours are the most critical for avoiding

groove echo build-up. The idea is to get the lacquer into the plating

bath as quickly as possible.

 

Pop music is so limited in dynamic range that groove echo is rarely a

problem except in the lead-in and in-between bands. Classical music is

difficult to cut, plate and press. It is ideal to have the lathe in the

same building as the plating plant. The only East Coast pressing plant

that has this is Europadisk in NYC. In the hey-day of lacquer cutting

there were 2 independent electroplaters in NYC and they would have

messengers pick-up the lacquers from all the cutting houses in New York

every day.

 

The second condition is called "Layer to layer transfer", or "Print-Through".

 

Print-through is the undesired low level transfer of magnetic fields from one layer of analog tape to another layer on the tape reel. Preprint, also known as pre-echo, is the print through signal that is on the outer layer of tape wind, thereby preceding the recorded signal. Postprint, or post-echo, is when the print-through signal follows the recorded signal.

 

Bruce Swedien

 

[KB Gunn]

So Nat's question was not answered accurately by all of us, except Bruce. Bob Ludwig's explanation covers both phenomenon, but obviously Groove Echo is the most influential cause of the effect that Nat was asking about.

 

Thanks for clearing that up Bruce.

[John Sayers]

 

So Nat's question was not answered accurately by all of us, except Bruce.

 

 

you obviously didn't read my post.

 

cheers

john

[steadyb]

Originally posted by Bruce Swedien OK Kiddies..... The first condition you described has to do with phonograph records and is "Groove Echo". Here's a great explanation by my old pal Bob Ludwig, the highly talented mastering engineer. I read this on the internet and was so impressed with his great explanation that I saved it! Ghost In the Machine: groove echo in vinyl disks. One of the great advantages of digital audio is that both vinyl records and analog tape suffer from the transmission of sound from one recorded layer of tape or record groove to the next. There is no cross-talk in digital, it is only limited by the associated analog circuitry. Groove echo, as it is called in the industry, is the result of a double whammy. The first whammy occurs in the cutting process and the far worse whammy occurs in the plating and even some in the pressing process. When a groove is cut into a master acetate the grooves are purposely cut as close to one another to maximize the recording time of the disk. 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. On a good lathe, each rotation of the lathe will result in the newly recorded part of the groove just touching the previous rotations engraving. On the last state-of-the-art lathes with computers (starting from about 1978) the newly recorded part of the groove actually nestles into the previous rotation! The sound of the deformed plastic of one revolution is probably always measurable in the next and on some occasions is audible. A newly recorded acetate is a joy to listen to. It is far, far quieter than the final pressing (no matter whose vinyl formulation is used), it is totally free of ticks and pops (until you touch it) and the groove echo is very low. The acetate is almost a living thing. How a lacquer electroplates is a function of how well cured the lacquer is. The amount of oils in the acetate are a function of how the manufacturer made it, how long it was cured at the plant, and how long it was allowed to acclimatize to the cutting room environment before cutting. After cutting, time starts to act on the blank and the groove echo begins to build up within the master lacquer. The first 24 hours are the most critical for avoiding groove echo build-up. The idea is to get the lacquer into the plating bath as quickly as possible. Pop music is so limited in dynamic range that groove echo is rarely a problem except in the lead-in and in-between bands. Classical music is difficult to cut, plate and press. It is ideal to have the lathe in the same building as the plating plant. The only East Coast pressing plant that has this is Europadisk in NYC. In the hey-day of lacquer cutting there were 2 independent electroplaters in NYC and they would have messengers pick-up the lacquers from all the cutting houses in New York every day. The second condition is called "Layer to layer transfer", or "Print-Through". Print-through is the undesired low level transfer of magnetic fields from one layer of analog tape to another layer on the tape reel. Preprint, also known as pre-echo, is the print through signal that is on the outer layer of tape wind, thereby preceding the recorded signal. Postprint, or post-echo, is when the print-through signal follows the recorded signal. Bruce Swedien

 

That's what I meant to say.