Analog Mono Formats

Phonograph cylinder

Early development of the phonograph cylinder

Thomas Edison conceived the phonograph on 18 July 1877 for recording telephone messages, his first test using waxed paper. In early production versions the recordings were done on the outside surface of a strip of tinfoil wrapped around a rotating metal cylinder. By the 1880s wax cylinders were mass marketed. These had sound recordings in the grooves on the outside of hollow cylinders of slightly soft wax. These cylinders could easily be removed and replaced on the mandrel of the machine that played them. Early cylinder records would commonly wear out after they were played a few dozen times; the buyer could then either bring the worn cylinders back to the dealer to be traded in as partial credit for purchase of new recordings, or have their surface shaved smooth so new recordings could be made on them. In 1890 Charles Tainter patented the use of hard carnauba wax as a replacement for the common mixture of paraffin and beeswax used on phonograph cylinders

Early cylinder machines of the late 1880s and the 1890s were often sold with recording attachments. The ability to record as well as play back sound was an advantage to cylinder phonographs over the competition from cheaper disc record phonographs which began to be mass marketed at the end of the 1890s, as the disc system machines could be used only to play back pre-recorded sound.

In the earliest stages of phonograph manufacturing various competing incompatible types of cylinder recordings were made, but in the late 1880s a standard system was decided upon by Edison Records, Columbia Phonograph, and other companies; these were about 4 inches (10 cm) long, 2¼ inches in diameter, and played about two minutes of music or other sound.

Gramophone record

A gramophone or phonograph record is an analogue sound recording medium consisting of a flat disc with an inscribed modulated spiral groove starting near the periphery and ending near the center of the disc. Gramophone records were the primary technology used for personal music reproduction for most of the 20th century. They replaced the phonograph cylinder in the 1900s, and although they were supplanted in popularity in the late 1980s by digital media, they continue to be manufactured and sold.

The terms LP record (LP, 33, or 33-1/3 RPM record), 16 RPM record (16), 45 RPM record (45), and 78 RPM record (78) each refer to specific types of gramophone records. Except for the LP, these type designations refer to their rotational speeds in revolutions per minute (RPM). Prior to the 1950's records were made out of shellac. Records made since the 1950's, including LPs, 45s, and 16s, are usually made of polyvinyl chloride (PVC), and hence may be referred to as vinyl records or simply vinyl.

Equalization

Due to recording mastering and manufacturing limitations, both high and low frequencies were removed from the first recorded signals by various formulae. With low frequencies, the stylus must swing a long way from side to side, requiring the groove to be wide, taking up more space and limiting the playing time of the record. At high frequencies noise is significant. Using equalization to an agreed standard can compensate for these problems. This simply means reducing the amplitude at low frequencies, thus reducing the groove width required, and increasing the amplitude at high frequencies. The playback equipment boosts bass and cuts treble in a complementary way. The result should be that the sound is perceived to be without change, thus more music will fit the record, and noise is reduced.

The agreed standard has been RIAA equalization since 1952, implemented in 1955. Prior to that, especially from 1940, some 100 formulae were used by the record manufacturers.

Reel to Reel recording is the form of magnetic tape audio recording in which the recording medium is held on a reel, rather than being securely contained within a cassette. In use, the supply reel or feed reel containing the tape is mounted on a spindle; the end of the tape is manually pulled out of the reel, threaded through mechanical guides and a tape head assembly, and attached by friction to the hub of a second, initially empty takeup reel.

The reel-to-reel format was used in the very earliest tape recorders, including the pioneering German Magnetophons of the 1930s. Originally, this format had no name, since all forms of magnetic tape recorders used it. The name arose only with the need to distinguish it from the several kinds of tape cartridges or cassettes that were introduced in the early 1960s.

American audio engineer Jack Mullin commercially developed the format in the late 1940s with assistance from Bing Crosby. Mullin had been a member of the U.S. Army Signal Corps during World War II. His unit was assigned to investigate German radio and electronics activities and in the course of his duties he acquired two Magnetophon recorders and fifty reels of Farben recording tape from a German radio station at Bad Nauheim, near Frankfurt. He had these shipped home and over the next two years he worked to develop the machines for commercial use, hoping to interest the Hollywood film studios in using magnetic tape for movie soundtrack recording.

Mullin gave a demonstration of his recorders at MGM Studios in Hollywood in 1947, which led to a meeting with Bing Crosby. Crosby immediately saw the potential of Mullin's recorders to pre-record his radio shows; he invested $50,000 in a local electronics company, Ampex, to enable Mullin to develop a commercial production model of the tape recorder. Using Mullin's tape recorders and with Mullin as his chief engineer, Crosby became the first American performer to master commercial recordings on tape and the first to regularly pre-record his radio programs on tape. Ampex and Mullin subsequently developed commercial stereo and multitrack audio recorders, based on the system invented by musician Les Paul, who had been given one of the first Ampex Model 200 tape decks by Crosby in 1948. Ampex went on to develop the first practical videotape recorders in the early 1950s to pre-record Crosby's TV shows.

The earliest reel-to-reel systems used metal wire as a medium (see wire recording), which is robust, but suffers from a number of problems—fidelity is poor, it requires a strong current to imprint the signal onto the wire, it is inconvenient to physically cut and splice to effect an edit, and the wire can kink or even tangle. The invention of cellulose acetate plastic tape coated with iron oxide solved these problems, opening up the use of tape recorders in studios. Wire was also used as a recording medium in black box voice recorders for aviation in the 1950s.

The great advantage of tape for studios was twofold—it allowed a performance to be recorded without the 30-minute time limitation of a phonograph disc, and it permitted a recorded performance to be edited. For the first time, audio could be manipulated as a physical entity. Tape editing is performed simply by cutting the tape at the required point, and rejoining it to another section of tape using adhesive tape. This is called a splice. The splicing tape has to be very thin to avoid impeding the tape's motion, and the adhesive is carefully formulated to avoid leaving a sticky residue on the tape or deck. Usually, the cut is made at an angle across the tape so that any noise introduced by the cut is spread across a few milliseconds of the recording. The use of reels to supply and collect the tape also made it very easy for editors to manually move the tape back and forth across the heads to find the exact point they wished to edit. Tape to be spliced was clamped in a special splicing block attached to the deck near the heads to hold the tape accurately while the edit was made. A skilled editor could make these edits very rapidly and accurately.