Mercury Matrix Number Variations

A “Matrix Number”, stamped (or inscribed) information placed between the last groove and the label, is always there, to indicate record number, mother stamper, and pressing plant.

With matrix number type, we can surmise the era when each platter is pressed. And Label variations also used for each vinyl also helps a lot to guess the pressed era.

Please note, that the variations on this site does not cover all known to exist: there are so many exceptions. So please understand the variations on this site are basic frameworks to identify famous patterns.

Matrix Number Variations: 1954? - 1960?

YMG 50026A  MF3  A1  I Matrix imprints of Mercury MG-50026 Side-A This stamper may indicate this disc was pressed using the first stamper (1) from the first mother (A) from the third-cut lacquer (MF3). This copy is YMG matrix as well as Indy pressing, which may suggest this was pressed in the transition era. Such type can be found on some Popular releases, as well as EmArcy 12-inch LP releases.

In 1952, legendary Living Presence series started. And a few years later (1954 or 1955) Mercury started to use RCA Victor's Indianapolis plant. All Indy-pressing discs always have “I” stamp on the dead wax.

In the very first year, matrix prefix was still YMG (same as previous type), but after a short while, prefix stamp was changed to smaller MG. This transition was made probably in the late 1955 or early 1956, at least judging from various discs in my collection.

This type can be found on such series as

• MG-20000 Series Monaural (Popular, 12-inch LP, late MG-20200 and before)
• SR-60000 Series Stereo (Popular, 12-inch LP, about SR-60100 and before)
• MGW-12000 Series Monaural (Wing R&B, 12-inch LP)
• MGW-60000 Series Monaural (Wing Jazz, 12-inch LP)
• MG-36000 Series Monaural (EmArcy Jazz, 12-inch LP，MG-36104 and before)
• SR-80000 Series Stereo (EmArcy Jazz, 12-inch LP)
• MG-50000 Series (Classical, 12-inch LP, about MG-50260 and before)
• SR-90000 Series (Classical，12-inch LP, about SR-90260 and before)

Especially, Indy pressings of Mercury Living Presence Classical series is supreme - fine blends of awesome recording technique and pressing qualities. So-called &lrdquo;FR-press” Living Presence LPs can give us great sound reproduction.

In 1958 and beyond, when Mercury started to release Stereo discs, all stereo LPs and Classical mono LPs were pressed at Indy plant, while other monaural LPs were pressed at Mercury's own plant (handwritten matrix inscription). This is probably because Mercury gave priority to Hi-Fi Stereo discs to use Indy plant over monaural LPs with some business strategies.

BTW very early discs' matrix suffix was MF (with YMG prefix), and later all discs had FR postrixes.

On the other hand, Popular releases and Jazz releases had MF (-1956), and MS (1956-). Some of the stereo discs have FR suffix which is common in Classical releases.

Please note that, there are some discs which were NOT actually pressed at Indy plant, although they have Indy-type matrix stamps. Such copies can be distinguished by the sound it reproduces, or by the feel of the edge of the discs. Such one might be pressed at other plants, using Indy stampers.

MG20090A  MF1  A3  I Matrix imprints of Mercury MG-20090 Side-A This stamper may indicate this discs was pressed using the third stamper (3) from the first mother (A) from the first-cut lacquer (MF1). This is the most basic Indy type.

SR80015A  FR1  A1  I Matrix imprints of EmArcy SR-80015 Side-A This is EmArcy Jazz Series' stereo LP, and it has the very same matrix type as Living Presence series. This stamper may indicate this discs was pressed using the first stamper (1) from the first mother (A) from the first-cut lacquer (FR1).