How vinyl records are made
The process of recording songs and getting them to the stage where the public can buy the product is quite complicated and prolongued.
This page hopes to break down the various stages and explain what has to be done and what the by products are, especially for collecting, including master tapes, acetates, stampers and test pressings.
This is by no means an expert account, more a simplified version for easy consumption.
Master tapes
Once a recording has been made in a studio, the master tapes are the starting point towards getting the songs onto vinyl. Traditionally, master tapes, have been on 1/4 inch reel to reel open tape and depending on the speed that the tape has been set, depends on the final quality.
The faster the recording speed the better the quality.
The following is a list of the varying speeds and their technicalities:
1 7/8 in/s or 4.76 cm/s — usually the slowest domestic speed, best for long duration speech recordings
3¾ in/s or 9.52 cm/s — common domestic speed, used on most single-speed domestic machines.
7½ in/s or 19.05 cm/s — highest domestic speed, also slowest professional.
15 in/s or 38.1 cm/s — professional music recording and radio programming
30 in/s or 76.2 cm/s — used where the best possible response is required e.g. many classical music recordings
in/s = Inches per second (or IPS)
cm/s = Centimetres per second
7½ IPS was the speed used for reel to reel releases of recordings and 3¾ IPS was the speed used for 8 tracks
The Friend or Foe album images shown here are of the reel to reel tapes that were recorded at 15 IPS. These images are of copy master reels that were produced for the Yugolsavian Suzy label to release the Friend or Foe album in Yugoslavia in 1982
Acetates
Producing an acetate record or more accurately a lacquer coated disc is the next stage.
The acetate is an intermediate stage prior to the production of the master disc and is used for test purposes to assess the sound transfer from the master tapes to vinyl. If a sound or mix is rejected then the acetate pressed has the potential to be a unique item as there are never many copies of acetates produced, usually no more than 10 and as such are highly sought after.
The acetate is usually an aluminium disc that is covered in a thin coating of nitrocellulose lacquer that has the sound groove, from the master tape, cut into it using a "lathe".
They come in various sizes including 7", 10", 12" and 14"
To the left shows the cutting head on the lathe, which is like a record player needle but in reverse. The sound is passed through the sapphire cutting stylus which etches the soft lacquer, by moving up and down, left and right, tracing out an exact waveform representation of the music. There is also a small vacuum cleaner beside the cutter to pick up the excess lacquer.
The lacquer is only soft and thin and repeated playing of the acetate will degredate the sound. They are manufactured for one purpose and that is for quality control and not repeated playing.
There are two types of acetates that are manufactured, single sided and double sided discs.
For single sided discs (as the Zerox single above is) when the mastering has been completed there will be two acetates to take away, one for the "A" side and another for the "B" side.
On the back of the these singles there are two peg holes, the centre one as with normal records to place on the turntable and the offset one. This second peg hole is for turning the disc on the lathe to stop the disc slipping.
There are two discs as you cannot proceed to the next step with a double sided acetate.
Double sided discs are essentially reference discs given to band members or record companies and are not sent on for the pressing and plating processes.
Pressing plates
Next is the plating and pressing processes.
At the pressing plant, stampers (or plates) have to be created from the acetates.
Each acetate is coated with a thin layer of silver nitrate and washed in stannous chloride which is then electro-plated with nickel. Once this has set the two are seperated and the plate produced will be a negative of the acetate with ridges instead of grooves.
This plate is called the "father plate" or the "master plate", which is then oxidised, plated again and when set the two discs are seperated, this time producing a "mother plate". The "mother plate" is an exact replica of the lacquer acetate that was originally brought into the plant and is used to check for any errors in the plating process.
From this "mother plate" further "father plates" are created using the above process and these plates are known as the stamper plates as they are the ones that press the actual records out.
This lengthy process is gone through as the stamper plates wear out after so many pressings and with having a metal "mother plate" on the shelf this enables as many "father plates" to be pressed as required.
The two stamper plates (one for the A side the other for the B side) are fitted to the vinyl press in preparation for producing the finished product.
Pressing the vinyl
Once the stamper plates are fitted into the press, the polyvinyl chloride grains (the plastic for the records) is made into a small block called a biscuit or a puck. Once produced the already prepared record labels are stuck to the top and bottom of the biscuit and then placed inbetween the stampers to produce the record.
The biscuit is then pressed and heated so that it melts and moulds to the shape of the stampers and at the same time the label is bonded to the vinyl.
The pressed record is then trimmed, as the excess vinyl from the pressing is still attached to the outer edges of the record.
The records are now ready to be tested and packaged.
Test pressings
Before the records are put out on general release, a small run of test pressings are produced.
These test pressings tend to be either printed with blank labels as per the ones on the left or specific "test pressing" labels as per the Prince Charming albums shown on the right.
These pressings are usually sent to members of the bands themselves and also the record companies for approval. If everything is deemed to be OK then depending on the size of the record company or the band, a run of promotional pressings will then be pressed.
Promotional pressings
After the tests have been approved, companies like CBS, will make a small run of promotional pressings, commonly known as "promos".
These are to send out to journalists, radio stations etc... to promote the record prior to the official release. This is to ensure that the record gets heard and has had reviews in advance, so that when the official release date comes around the general public are ready to buy the product and ultimately get it into the charts.
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