I know that Ray appreciates someone who has knowledge of the subject pointing
out any errors in the articles he posts
Jewel
----- Original Message -----
From: Max Robinson
To: [email protected]
Sent: Friday, June 08, 2007 4:04 PM
Subject: Re: [BlindHandyMan] LP Records and how they are Made.
A couple of corrections.
Edison's invention wasn't called the victrola. That was a registered
trademark of the Victor corporation. The machine that was known as the
Victrola played disk records not cylinders.
Then the article says...
In about 1887, Valdemar Poulsen, a Danish scientist, used the same
principles to record sound on a magnetic tape.
I don't believe that. First of all, the principle of acoustic recording and
magnetic recording are very different. Edison's machine used no
electricity, except maybe to make the cylinder go around. The home playback
machines used a spring motor for that. I aught to know because I own to of
them with about 350 cylinders.
Magnetic recording couldn't have been done in 1887 because there weren't any
vacuum tubes to amplify the small signal from the playback head for
reproduction by a headphone. Recording could have been accomplished using
telephone techniques but there would have been no way to play it back.
I have heard of experiments and demonstrations of magnetic recording on
metal tape done in the 1930s. The Germans perfected magnetic wire recording
during WW II and Sears Roebuck marketed a successful wire recorder in 1948.
I have one of those also.
Magnetic tape came into the radio and recording studio in 1950 and hit the
consumer market about 3 years later. It quickly replaced the wire recorder
because the tape was more robust than the somewhat fragile wire.
Just because somebody posted it on their web site doesn't mean it is
correct. Please don't take this personally Ray. I know you do a lot of
hard work for the list. Keep posting and the rest of us will jump in when
we spot an error.
Regards.
Max. K 4 O D S.
Email: [EMAIL PROTECTED]
Transistor site http://www.funwithtransistors.net
Vacuum tube site: http://www.funwithtubes.net
Music site: http://www.maxsmusicplace.com
To subscribe to the fun with tubes group send an email to,
[EMAIL PROTECTED]
----- Original Message -----
From: "Boyce, Ray" <[EMAIL PROTECTED]>
To: <[email protected]>
Sent: Thursday, June 07, 2007 10:08 PM
Subject: [BlindHandyMan] LP Records and how they are Made.
Hi Everyone
How is an lp record made?
Background
Sound has always
fascinated
human listeners, but, until late in the 1800s, it eluded capture. This fact
seems peculiar to us today because, with compact discs, cassette tapes,
highly
portable players, automobiles with
lush
sound systems, hundreds of radio stations on the dial, television stations
devoted to music, and a
myriad
of other broadcast sounds, we are surrounded by sound.
Among the solid forms that music and other recordings have taken in their
brief history, the long-playing
phonograph
record may be the most romantic and among the most cherished. Phonograph
records are no longer manufactured except by private parties with the
equipment
and the interest, and most sound systems are not equipped with turntables.
Long-playing records, known as LPs, are coveted by collectors, however, and
there is a large secondary market in used records among aficionados of
particular types of music like jazz or opera or performers like
Frank Sinatra
or the Beatles.
History
The long-playing record was a direct descendant of the first record made and
played on November 20, 1877, by Thomas Edison. Edison's bounty of inventions
came from a thorough understanding of science. Edison knew that sound
consists of a vibrating wave of air molecules that enters our ears, strikes
the
eardrum
and sets up vibrations in the tiny bones of the inner ear, and passes along
nerve endings to the brain. The brain decodes these vibrations as sounds.
The
number of vibrations per second is the frequency of the sound, and those
vibrating waves have
amplitude
or size that we interpret as loudness or softness. Any and all sounds have
these properties so, to record a bird's song, the symphony of vibrations
produced
by the instruments in an orchestra, or the voice of the lead singer in a
rock band, the same techniques are used.
Edison's victrola recorded the sound and played it back. He used a metal
cylinder with open ends that was wrapped with a sheet of
tinfoil.
By speaking into a "sounding disc" that vibrated and was attached to a
stylus or needle, the vibrations Edison created by speaking were etched by
the stylus
onto the tinfoil. The etching looked like small hills and valleys that
spiraled around the cylinder. To play back his recording, Edison moved the
needle
back to the start of the record of the vibrations and revolved the cylinder
at the same speed as it had moved during recording. The vibrations came back
out of the sounding disc and were amplified by the cup, or primitive
microphone,
into which Edison had spoken.
Following significant improvements to his phonograph, the first records were
made of wax cylinders. Jules Levy, a
coronet
player, is credited as being the first recording artist. He played "Yankee
Doodle" on his coronet, and the wax cylinder of his rendition could be
played
at home on the Edison Parlor Speaking Phonograph (the first home-use
phonograph), which sold for $10 in 1878.
In about 1887, Valdemar Poulsen, a Danish scientist, used the same
principles to record sound on a magnetic tape. At the turn of the century,
the infant
recording industry made cylinders of various materials with permanent
recordings on them, but World War II pushed the magnetic tape into broad
acceptance
as the medium for recording sound and then transferring it to records.
Leading recording companies like RCA Victor found that magnetic tape
produced greater
fidelity, or faithful reproduction of sound, than other methods. Also, tape
can easily be cut and edited to shorten,
lengthen,
or remove performance errors from recordings.
Until just after World War II, records were available in only one playing
speed and turned on their turntables at a rate of 78 revolutions per minute
(
rpm).
In 1948, Peter Carl Goldmark (1906-1977), an American physicist who had been
born in Hungary, invented a record that revolved at less than half that
speed,
at 33.33 times per minute. Improvements in production also allowed the track
(the groove for the needle) to be narrowed, and these two developments
allowed
six times as much music to be recorded on a single record. Large-scale
record production was ready for the age of Elvis and rock and roll, and
entire symphonies
could be
reproduced
on a single long-playing album instead of a set of 78s.
Raw Materials
The raw materials for record manufacture were subdivided into those needed
to make the master disc, those for actual pressing of the records, and the
paper
goods needed for labels, sleeves, and jackets. The master disc was made of
black
lacquer,
so it could be etched with grooves to carry the sound. Silver was used to
coat the finished disc, and chromium-plated nickel discs were used to press
the
"vinyl" records.
Records were most commonly made of black plastic, although some were
produced in other colors. Recording companies developed the designs for
their own labels,
sleeves, and album jackets; however, manufacture of these was usually
subcontracted to paper suppliers and printers.
Design
Records evolved into three sizes and three forms of sound reproduction.
Originally, records were played at a speed of 78 revolutions per minute
(rpm) and
were called 78s. The 78s were largely replaced by long-playing records, also
called LPs and 33s because they revolve when played at 33.33 revolutions per
minute. Records with a single song on each side were known as singles and
also called 45s because their playing speed was 45 revolutions per minute.
In their early years, these records were
monaural
with sound that usually only came from one needle or speaker and seemed to
have only one dimension or source direction. As technology improved, sound
was
recorded in stereo or quadrophonic sound that was also typically projected
from two or four speakers and was more realistic because it captured sound
as
we hear it with two ears.
Standardized record players prevented much variation in physical design of
the record. Creativity, instead, came from the recording studio but also
from
the artists, writers, and researchers who developed the artwork and text on
the album jackets. Today's collectors are often as interested in the rare
photos
and drawings and historical narratives on the record jackets as they are in
the music inside.
The Manufacturing
Process
Recording the sound
* In the recording studio, microphones are located in several different
places depending on the acoustics (sound-bouncing properties) of the room
and the
music being recorded. There are different types of microphones: a
specialized microphone for a vocal
soloist
and several others for instrumental backup, for example, are used. The
microphones hear the sounds and translate them into bursts of electrical
current
that are fed to the recording head on a magnetic tape recorder. The head is
made of layers of metal that formed an electromagnet, and the magnet
transmitted
the current as a pattern of sound waves to the magnetically sensitive tape.
The flow of the current or magnetism varies with the intensity of energy
picked
up by the microphone as sound.
* The magnetic tape consists of a long ribbon of 2 in (5 cm) wide plastic
that is coated on one side with
iron oxide.
As the tape winds its way through the machine and across the face of the
electromagnet, the iron
oxide
responds to the changes in current or magnetic flow so a permanent picture
of the sound was formed on the tape by the rearranged particles. The pattern
can be seen with a
microscope
but not with the naked eye. It is, however, permanent and very precise.
* During a recording session, sound engineers monitor the work in progress
to make sure that every note is captured on tape. The 2 in (5 cm) wide tape
is
divided into 16 separate tracks, each of which records particular
instruments, voices, orchestra sections, or sound from different
microphones. During
recording, the sound engineer also manipulates the master control board to
add special effects or modify the sound he hears from one instrument or
section.
The master control board also shows the recording levels on each track so
these could be made softer or louder. The sound engineers then "do the mix"
when
the recording is finished to adjust the balance of the various instruments
or singers. They may emphasize a particular instrument during one song, for
example, and minimize it during another.
* Sometimes the sound from a particular instrument or voice is not right for
the finished recording, and the artist is called back to the studio to
rerecord.
This process is called overdubbing and adds another part to a separate track
on the tape or to a multi-track master. If the tape is overdubbed, it may
also have to be remixed. Sometimes, the collection of artists recording the
music can not meet in the recording studio at the same time; in that case,
the sound engineers record the rhythm tracks first, then the singers and the
strings. This multiple process is called
sweetening.
The record producer and the sound and mixing engineers work together on the
final mix. The tape is then edited to produce the collection of sounds heard
on the final recording. The finished tape, called the master tape, is used
to make a master disc.
Making the master disc
List of 5 items
* The master disc is made of aluminum coated with soft black lacquer and
called a lacquer. The responsibility for making it rests with the mastering
engineer.
The mastering engineer fits all the sound for one side of the record in the
specified width of the playing space. For instance, the sound for a 45-rpm
record is allowed to occupy a 1.1875 in (3 cm) wide space for grooves on the
record, regardless of whether the song was three to five minutes long. The
mastering engineer experiments with the spacing of the grooves. The work of
the mastering engineer is critical because the master disc he produces is
used
as the model for pressing thousands of records. Loud music requires large,
fat grooves, while softer music takes narrow grooves.
* The mastering engineer controls the space taken by the record grooves most
easily by manipulating the volume; however, if more than one song appears on
one side of the album, it is also important to keep the volume relatively
constant. For the best sound quality, mastering engineers try to use the
loudest
possible volume. They also use microscopes to inspect the grooves, and they
are very
adept
at recognizing sounds by their grooves.
* Mastering engineers use a special grooving machine called a Variable Pitch
Cutting Lathe that is equipped with an electronic
cutting stylus
to
etch
the grooves in a hard plastic disc. The master disc looks much like a
record, but it is larger. A 7 in (17.8 cm) diameter, 45-rpm record is cut
onto a 10
in (25.4 cm) diameter blank. A 12 in (30.5 cm) diameter, 33.33 LP is cut
onto a 14 in (35.6 cm) diameter blank. The grooves are just like the
patterns
of iron oxide particles on the magnetic tape in that they imprison the sound
vibrations in plastic. As the lacquer is cut, the stylus is heated to help
it cut more
smoothly.
The cutting
lathe
also has a small vacuum-producing tube mounted next to the stylus. It
vacuums up the continuous thread of black lacquer as the grooves are cut.
This spiral
of waste lacquer is called the chip.
* The mastering engineer scribes (marks) the cut disc on the outer edge with
identification information including the name of the song or album, the
master
number that also appears on the master tape, and the type of sound
recording, which is monaural, stereo, or
quadraphonic
sound. At this point in the manufacture, the record producer and the artists
may listen to a "reference acetate" or the master disc before it is
completed
in a final set of steps. After the master disc is cut and approved for
production, the disc is plated with a very thin coat of silver. It is then
called
the metal master and is the basis for all the records manufactured.
* At the plating plant, a metal
mold
is formed from the metal master, and liquid nickel is poured into the mold
to produce a nickel stamping record from each side of the metal master.
These
stampers are also electroplated with
chromium
that is less than one hundred thousandth of an inch (2.5-5 cm) thick. The
chromium coat protects the stampers from scratching.
Producing LPs
* LPs are produced in factories called pressing plants that usually are
located some distance from the recording studio, the birthplace of the
master disc,
and the plating plant where the stampers are made. A pressing plant is
capable of producing up to 185,000 records per day. The plastic or vinyl for
the
records is produced by melting plastic powder in a heated
mixer.
The plastic is melted and mixed until it has the consistency of
jelly.
It is then fed through a roller press that produces long, thin sheets within
strict tolerances for the thickness and
brittleness
of the plastic. When the sheets are cooled, they are cut into squares called
biscuits. An automatic press is fitted with the nickel stampers-one for each
of the two sides of the record. The biscuits are reheated to
soften
them slightly, and they are fed into the press. The operator makes sure the
biscuit
is seated properly and activates the press. The grooves and the sound
pattern are pressed into the soft plastic. This same process is used for
both long-playing
records and singles.
* Still square shaped, the stamped biscuits are conveyed to another machine
where the labels are pasted on, and the square corners are rounded. The edge
of the disc is smoothed, and the center hole is drilled through the labels
and the finished disc.
* In an alternate version of the same process, the automatic press is fitted
with the stampers (the two sides of the album), the round record labels, and
a
coil
of black vinyl plastic. The press is heated to 300°F (149°C), causing the
plastic coil to melt and spread between the stampers and into the grooves in
a
process similar to
injection molding.
This same machine forms the hole through the center of the record. A flash
cutter
is used to trim and finish the edge of the LP.
* In the finishing department, each record is carefully inspected before
packing. The newly pressed record moves to a packaging station where it is
inserted
in a paper or
cellophane
envelope or sleeve, slipped into the printed record jacket or album cover,
and then shrink-wrapped with plastic. Packing boxes filled with the packaged
record albums are shipped to distributors.
Quality Control
Historically, sound engineers in the studio carefully monitored all aspects
of recording to make sure the most desirable sound quality was recorded. The
mastering engineer's job was to transfer that quality to a reproducable
master disc within the technical constraints of the size of the record and
its
grooves. After a test pressing was made, the record producer (and sometimes
the artists) had the opportunity for an important quality control check in
reviewing and approving the test pressing.
In the record factory, operators checked the biscuits and the motions of the
press and provided ands-on monitoring of the pressing of records. The
finishing
department also inspected the final product for scratches,
bumps,
and other irregularities and cleaned each LP before it was packaged. After
the records were sealed in their jackets and boxed in bulk, an independent
group
of testers chose packaged records randomly and removed them from their
packaging. These testers checked the packaging itself, played the records,
and inspected
them for any flaws.
Byproducts/Waste
Flawed records were melted and pressed again, as were the square corners
that were removed from the biscuits to make them into round LPs. The chip of
waste
lacquer from the making of the master disc was recycled, and any nickel or
chromium from the metal processing portions of master disc production was
carefully
controlled and recycled.
The Future
The manufacture of long-playing records is a thing of the past. Compact
discs stepped to the
forefront
of recordings in the 1980s because they are not worn by playing, they are
more convenient in size, and their sound reproduction quality is better. All
sizes
of vinyls, however, have many fans among collectors. Some recordings simply
have not been remade in compact disc form and are only available on LPs.
More
often, collectors treasure the collectible character of these records for
their sounds, the kinds of music they preserve, and the artwork and
information
on record jackets.
Where to Learn More
Books
Edmunds, Alice. Who Puts the Grooves in the Record? New York: Random House,
1976.
Miller, Fred. Studio Recording for Musicians. New York: Amsco Publications,
1981.
Wullfson, Don L. The Kid Who Invented the Popsicle: And Other Surprising
Stories About Inventions. New York: Cobblehill Books, 1978.
Periodicals
Althouse, Paul "Audio: whither LP?" American Record Guide (May-June 1994):
236.
Egan, Jack. "Where's the value in vinyl?" U.S. News & World Report (December
13, 1993): 106.
McKee, David. "The flip side." Opera News (October 1997): 70.
Scull, Jonathan. "All Sales are Vinyl." Atlantic Monthly (December 1997):
106-112.
Other
"A Science Odyssey: Everyday Objects."
http://pbs.org/wgbh/aso/tryit/tech/indext.html/.
"Newton's Apple: Which sounds better: an LP or CD?"
http://wwwO.pbs.org/ktca/newtons/l1/cdlp.html/.
"This Week in Music History."
http://cgi.canoe.ca/MusicHistoryJune/june21.html/.
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