KOCH is a nickname used by Austrian company Koch Digitaldisc GmbH, which ran a CD manufacturing plant in Elbigenalp from 1985-1998. KOCH Digitaldisc merged with Dureco in 1998, after which the manufacturing plant continued operations under the name kdg. KOCH may be named in the disc matrix, or it may be identified based on the NNN.NNN.NNN.NNN.N and SID codes described in the following sections.

Matrix numbers:
CDs manufactured by KOCH feature a matrix number in the format NNN.NNN.NNN.NNN.N. The first 6 digits, NNN.NNN, appear to be a sequential numbering scheme assigned by KOCH, which can be entered as the catalogue number for KOCH. The following 7 digits are often related to the release catalogue number, and should not be entered as part of KOCH's catalogue number.

Example:

Catalogue#: 377.0029.2.41
Matrix: 038.597.377.0029.2
LCCN entry: Pressed By – KOCH – 038.597

Example:

Catalogue#: ENJ-9301 2
Matrix: 812.829.009.301.2 ['mastered by KOCH' logo]
LCCN entry: Glass Mastered At – KOCH – 812.829

When the matrix number is in the form 000.000.NNN.NNN.N, no part of it should be entered as the catalogue number for KOCH.

Preferred LCCN role(s):
· Glass Mastered At - when the 'mastered by KOCH' logo is present in the matrix, or with mastering SID code IFPI L17*
· Pressed By - KOCH named in the matrix with no specific role given (with or without mould SID code), or with mould SID code 30**
· Made By - when the text 'MADE BY KOCH' is present in the matrix

Glass masters:
Glass masters may originate from other manufacturers, probably before KOCH installed its own in-house mastering equipment. When 'CDMxx' is present in the matrix, please add Glass Mastered At – CDM (10) (see that label profile for more info) and credit KOCH with Pressed By or Made By as instructed above.