Sonopress

Gütersloh, Germany

Sonopress manufactured most of Geffen's vinyl in mainland Europe in the beginning of the 90's, before the majority of the vinyl production was moved to Holland in 1992 when Sonopress stopped manufacturing vinyl [1]. In Nirvana's case, they pressed Nevermind and the two first singles from the album, and a Bleach reissue. Sonopress cut copper mothers and lacqurs, and electroplated stampers in-house.

Matrix codes for 12" records follow the pattern below, here represented by the known variations of side A of Nevermind (GEF 24425). The third variation is also shown in image 1. Side B matrix codes follow the exact same pattern. Everything but the roman numerals are machine stamped:

Nevermind side A matrix, variation 3
1. Nevermind side A matrix, variation 3

The lathe numbers, here "108" and "201", identify the lathes which cut the copper mothers. More Sonopress lathe numbers are listed further below. "DM" shows that the record was cut with direct metal mastering (DMM). 7" records have similar matrix codes, but none of them have "DM" in the matrix codes. It is uncertain whether they were actually cut on lacquers or if "DM" was omitted from the codes for some reason. The grooves do look like they were cut with DMM. The same lathe numbers appear on both 12" DM records as well as 7" non-DM records, though it is probably possible to cut lacquers and copper plates on the same lathe if you change the cutting head and some settings.

The following code, in this case "F-5752", identifies the master tape which was used to cut the metal mothers. These master codes have also been found starting with G. In fact, the codes are the same for CDs and records if they contain the same tracks. The three track Smells Like Teen Spirit 12" (GET 21673 and GET 21712) and CD (GED 21673) pressings share the same master code, "F-5765". The prefix letters seem to just be an addtional way of counting, the master after "F-9999" would be "G-0001", and so on. On CD releases of Nirvana, "H" and "I" have also been found.

"A-1", "A-2", and so on, tell how many copper mothers were cut of side A from the same master. In this case, side A was cut at least three times. It is unlikely that they were cut with slave lathes, as A/B-1 and A/B-2 were often cut on the same lathes, but it is a possibility in some cases. The significance of the "C" found on many records is unknown.

The roman numerals, or lack of, are not the stamper numbers, but seem to identify copied mothers. In other words, the original master mother was electroplated to produce a stamper/ father, which was again electroplated to produce a new mother, which was marked "II". The stamper/ father was then electroplated again, and the second new mother was marked "III". Multiple stampers were then produced from each of the mothers. All stampers produced from a specific mother then contain the same roman numerals, and records without roman numerals were pressed with a side A stamper made from the original mother. From this, we can deduce that A-3 records without roman numerals also exist.

Lathe numbers

062, 108, 109, 110, 111, 201, 202, 207, others(?)

References