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This is very interesting. I have noticed three things about these references and your discussion. 1) All of these are relatively recent. 2) They tend to be European. 3) They are mainly discussing CD replication CDs are injection moulded, and in this process the discs are not really pressed or "stamped", they are moulded when the liquid is injected into the already closed press. It could almost be said that calling the mould a stamper is incorrect!! Although the same is true with injection moulded styrene and vinyl records, because the metal part is the same whether it is placed in a compression moulding or injection moulding press, during the days of grooved records it was called a stamper in either case. (Of course Edison called his cylinder masters "moulds", but I don't remember what the Edison disc masters were called -- the Diamond Disc manufacturing process was called "printing" not "pressing". Considering that the older printed sources you referenced to which call the part "stamper" are pre-CD, it is possible that the use of "son" came about during the CD era when no compression moulding -- or stamping -- was being done. On the other hand, your personal stories about the earlier use of son in Sweden are interesting and they are at the same level as my anecdotal experience of hearing only the use of stamper! That's why I asked about printed sources since I could provide those beyond my anecdotes. Since the CD was developed by European and Japanese firms, if these companies used "son", it probably caught on quicker in Europe. I haven't heard American CD replicators using "son", only "stamper", but you do show some American sources. However these sources seem to be from companies and people which come only from a CD background without having prior experience in grooved records. (Remember a month ago when we had a reference to a modern California vinyl pressing plant website which had a weird description about 78s being made from shellac sheets glued to a heavy paper core -- how much do the younger modern "experts" know about the history of their industry?) I might mention that the use of the term "father" is also rare -- but not unknown -- in my experience, but the term "mother" is almost universal!! I have never understood why mother came to be so common while father is rare and son was non-existent to me before this discussion. The female metal part was given a descriptive female name by just about everyone, but why not the mail metal parts? And I am rather surprised that none of the discussion included the term "shell" which was seemingly the official term of the Gramophone Co. to describe the metal positive pulled from the original wax. This term is used from the very beginning of the company but I don't see it used by Victor, at least not as much. I am eager to hear from my friend George Brock-Nannestad about this discussion since he had done a lot of study of the technical documentation in Europe in probably every language. Is he on vacation, or pouring thru a basement full of books and photocopies trying to research the facts before answering? Mike Biel [log in to unmask] =============== From: Goran Finnberg <[log in to unmask]> Michael Biel: > Actually I don't think that anyone has ever heard of it. > I have read hundreds of books, articles, instruction > manuals, guidebooks, etc. about recording techniques > and technology dating from all eras of the industry, > but have never seen anything relating the stamper to > the word "son". Can you cite me some specific sources > in print that use this term? I'm not saying that it > has never been used, but it must be quite uncommon, at > least in English. I have worked as a consultant to Skandinaviska Grammofon AB in Amal, Sweden, owned by EMI for most of its life, 1974 to 1989. It was supposed to be the largest vinyl record pressing plant in Europe at that time mid 70´s. All the production people called the parts Father, Mother and Son. Including calls to EMI England, or when EMI people turned up at the factory in Sweden. Toolex-Alpha once world leader in vinyl pressing equipment called the parts Father, Mother and Son in the tree day seminar I went to in the 70´s. And this continued when they began producing presses for CD production when I helped out some friends who started Logos AB here in Gothenburg which was once a cassette duplicating plant but later on started producing CD´s. Sonopress in Germany, and many more too many to list, also referred them to be Father, Mother and Son. In fact dealing with hundreds upon hundreds of companies professionally involved with mass duplication of Vinyl or CD disks here in Europe I have always seen, Father, Mother and Son, to be used as description of the three stages used to provide a replicated LP/CD disk to be used as the final carrier to be sold in the retail shop. Using Google with the keywords: Record Pressing Father mother son stamper Turned up several hundred hits to numerous to list here but I looked at a few: http://www.soundonsound.com/sos/sep03/articles/artwork.htm The etched glass master is not used to stamp discs itself, but is used to create a metal stamper through a process called electroforming. A layer of nickle is effectively grown onto the disc, transferring the etched pits on the glass into bumps in the metal disc to produce a 'father' disc. For very short CD pressing runs, this father can be used as the direct stamper, but it is more common to produce one or more 'mother' discs from the father, and then several 'sons' from each mother. The sons are used as stampers to produce the raw plastic CD discs ------------------------- http://www.pctechguide.com/32CD-ROM_Manufacturing.htm In a process known as "electroforming", the metalised glass master has a layer of nickel grown onto its silver surface by immersion in a tank of nickel sulphamate solution. This sheet of nickel - referred to as the "father" - is subsequently removed from the silver. The father is a reverse image of the data and could be used to stamp discs. However, it is not. Instead, the father is returned to the electroforming tank where another layer of nickel is grown and subsequently removed to create a "mother". The mother undergoes the same process to produce a "stamper" (sometimes referred to as a "son"). Several stampers can be grown from the same mother. CD Pit Structure ------------------------- http://www.freepatentsonline.com/y2009/0232928.html " Also, a mother stamper or a son stamper may be manufactured from the father stamper. " ------------------------- http://www.faqs.org/patents/app/20090195925 [0106]Further, in the same manner as a procedure of obtaining the mother stamper from the father stamper, an oxide film is formed on a surface of the mother stamper, and an Ni film is electroformed and released, thereby obtaining a son stamper having the same patterns of the father stamper. --------------------------- http://www.odiscs.com/cd/cd_structures_formed.htm After the exposed areas are developed away by conventional methods to produce pits, a rigid metal negative to the master, called the Father or Master stamper, is produced by an electoplating process (see Figure 2). A multiple positive image Mother may be electroplated from the Father stamper. In turn, negative image Son stampers are plated from each Mother to produce multiple copies of the original master. Mass replication of the source begins by mounting a Father or Son in a molding press. Melted plastic is injected into the cavity and allowed to cool. The pits from the stamper are accurately reproduced in a plastic substrate, forming the original positive image. -------------------------- http://www.answers.com/topic/compact-disc Next, the newly applied metal layer is pulled apart from the disc master, which is put aside. The metal layer, or father, contains a negative impression of the disc master track; in other words, the track on the metal layer is an exact replica, but in reverse, of the track on the disc master. * The metal father then undergoes further electroforming to produce one or more mothers, which are simply metal layers that again have positive impressions of the original disc master track. Using the same electroforming process, each mother then produces a son (also called a stamper) with a negative impression of the track. It is the son that is then used to create the actual CD. * After being separated from the mother, the metal son is rinsed, dried, polished and put in a punching machine that cuts out the center hole and forms the desired outside diameter. -------------------------------------- http://www.patentstorm.us/patents/6814897.html According to a preferred embodiment of the invention, a first metallic (Ni) mold tool (father) is made which is a duplicate of a master substrate, then a resin mold tool (mother) is made which is a duplicate of the first metallic mold tool and finally a second metallic (Ni) mold tool (son) is made which is a duplicate of the resin mold tool. Both the father and son may be referred to a ³stamper². --------------------------------------- As I have also had to deal with Georg Neumann record cutting equipment then all the descriptions dealing with what happens after the laquer being cut then the descriptive words Father, Mother, Son was always used. Nowadays I am helping a young man who have bought an old Neumann VMS66 cutter here in Gothenburg and he recently added record plating equipment to his services and without no promting from me he called the process Father, Mother Son when he spoke about this process as he had learnt it from the previous owner. http://www.tailrecvinyl.com/ So to me at least, this is universally used here in most parts of Europe. But looking in the 1973 edition of the EMI Technical Glossary page M2 says: MATRIX: A metal part, originally produced from a laquer master, by the electrodeposition of nickel: 1. Metal Master (Negative). 2. Metal Mother (Positive). 3. Metal Stamper (Negative). It is stated at the very beginning: The terms used here are the most commonly used in the recording and manufacture of gramophone records. Gilbert Briggs, owner of Wharfedale loudspeakers, England in his book A to Z in audio, 11/1960 states on page 166: The sequence of record processing is as follows: 1.Laquer original - positive. 2 Metal Master - negative. 3 Metal Mother - positive. 4 Metal stamper, known as the working matrix - negative; 5 pressing - positive. The above presumably comes from the DECCA/London pressing plant at that time. And I just consider the use of the above to be as common in certain quarters as Father, Mother, Son is to me. None of them is wrong one should just be aware that depending on where you are in the word that different words are used to describe the exact same process. I could just use the word "Working Matrix" to describe the Son or Stamper and old ones in the production industry would understand at once what I meant. Work part can be used too in a pinch....;-) -- Best regards, Goran Finnberg The Mastering Room AB Goteborg Sweden E-mail: [log in to unmask] Learn from the mistakes of others, you can never live long enough to make them all yourself. - John Luther