The DMM Dubplate and the Art of Pushing the Boundaries, Part One

Before I begin writing about the DMM Dubplate Vol. 1 disk, recently released by Stockfisch Records of Germany, some background is essential for a full appreciation of what this actually means, in technical and even philosophical terms. There is much more to be communicated here than mere wine tasting lingo describing the sound (full-bodied, almond aftertaste?)…

Direct Metal Mastering (DMM) is a patented and trademark-protected process, invented by Teldec (Telefunken-Decca) in the 1980s. Prior to that, all records started life as master disks cut on a soft material (the so-called wax of the acoustic and early electrical recording era, or the lacquer which dominated after the 1930s). This soft material could be played back, but would be destroyed in the process and no longer able to be used for the mass-manufacturing of vinyl records. The unplayed master disk thus had to be “metallized,” using a vacuum sputtering process for wax or a “silvering” process for lacquer (spraying the surface of the disk with a silver nitrate solution to make it conductive) and then electroplated in a galvanic bath, where a layer of nickel would be grown on the disk by means of an electrochemical reaction. (Note: Readers interested in a more elaborate description of the record manufacturing process can find it in Copper Issues 92, 93 and 94. Those interested in a rather more exotic implementation of the same principle for purely artistic purposes may find the author’s vacuum tube electrochemical synthesizer mildly entertaining: https://agnewanalog.com/the-vacuum-tube-electrochemical-synthesizer-type-8001.html)

This nickel layer is also grown within the groove structure, so when the nickel part is pulled apart from the soft master disk, its newly exposed surface contains ridges instead of grooves. The nickel part is the first negative (think of the term “negative” as commonly used in film photography) and is often called the “father.” This part can now be mounted on the molds of a hydraulic press and used as a stamper, to press out multiple copies of the record. However, as stamper life is limited and more records may be needed than what could be produced using a single stamper, the father is not usually used as a stamper. Instead, it is electroplated once again to produce its mirror image, a positive (a disk that has grooves and not ridges), which is called the “mother.” The mother is made of nickel and is durable enough to be played back on a regular turntable. The mother is subsequently plated again multiple times, to create several sets of negatives to be used as stampers.

So where does the DMM process differ? The difference is that the DMM process produces the mother in a single step. In the DMM process, the master disk is cut directly on copper. The blank disk is actually a thick stainless steel disk, polished and electroplated with copper phosphate on one side. The copper layer is what the grooves are cut into. This master disk is actually also the mother. No other steps are necessary. The copper layer is already electrically conductive, so no silvering/sputtering process is needed. Just like the nickel mother, the copper mother can be plated several times to create multiple sets of stampers. It is sturdy enough to withstand being played back on a turntable and, unlike a lacquer or wax master, it can easily survive the temperatures in a galvanic bath, enabling it to be used for multiple plating passes.

The primary attraction of DMM was that it offered significant savings in cost, especially in a busy pressing plant with the ability to create the blank DMM disks in-house and recycle them in the galvanic department. However, the only disk mastering lathe designed to cut copper DMM masters was the Neumann VMS-82, using the Neumann SX-84 cutter head. There were very few of these ever made, and even fewer surviving to this day. A few were permanently converted to cut lacquer masters, a few were destroyed, and of the 12 machines known to have survived, five are now owned by the Church of Scientology, which they use to cut L. Ron Hubbard’s speeches on metallic disks, which they then hide in caves along with specially designed, hand-cranked turntables, for the aliens that will visit earth long after humanity has expired to find… No, seriously. The remaining machines are in regular use in busy mastering facilities in Europe (in the entire American continent, only the Church of Scientology is cutting DMM!), and two are set up at Pauler Acoustics in Nordheim, Germany. This mastering facility is also the home of Stockfisch Records. The original intent for the two VMS-82 lathes at Pauler Acoustics, and most probably their most frequent application, was for doing Direct Metal Mastering for vinyl record manufacturing.

However, the DMM Dubplate concept, which these lathes are also used for, is a rather radical departure from everything you thought you knew about disk records.

Before proceeding any further in my technical and not-so-technical revue of the blues, rhythm and blues, human absurdity and of disk mastering technology, I feel that I should unwind a little bit, take off my lab coat, and tell you a story about my personal life. In my early teens, I had a small record collection (in addition to having access to the much more substantial record collection of my father), which I was trying to augment with every opportunity I had. One day I started realizing that some records in my collection sounded significantly better than others. So, I put these aside, trying to figure out what they had in common. They were not all of the same artist, they were not on the same record label, they had not been recorded in the same studio, they had not been produced by the same producer, they were done several years apart, and the artists involved were not even all from the same country.

So, what was it that made the difference?

Since the record sleeves had failed to provide me with any obvious hints, I started pulling out the records themselves and looking carefully at the labels. While the labels also proved inconclusive, I noticed for the first time that there was something scribed on the record itself, between the lead-out grooves (the part towards the center label of the record, where the grooves open up to lead the tonearm out to the locked groove, signaling that the record has ended).

It didn’t make any sense.

It just said, G. Pauler!

Who is G. Pauler?

There was no mention of this name anywhere on the credits on the sleeve. I checked another one of the good sounding records and sure enough, there was G. Pauler scribed on it again! And then another one, and another one… Most of my better-sounding records had G. Pauler written on them. I felt that I had stumbled upon something significant, so I actually checked all the not-so-good sounding records for comparison, and none of them said G. Pauler. It was then that I realized that whoever this G. Pauler was, it must have to do with manufacturing the records, since it didn’t appear to have anything to do with recording the music. When the internet came, one of the first things I used a search engine for was “G. Pauler,” or rather, “who the f%#& is G. Pauler and why is his name on all the good-sounding records?,” to which the answer was that Günter Pauler is a mastering engineer who cuts masters for vinyl record manufacturing.

This is how I was inspired to find out what mastering actually is, and to learn about exactly how records are made. Not only that, but I also realized what a difference it actually makes, and how much care is put into the disk-mastering stage. I was so fascinated by this discovery that I decided I wanted to become involved in the engineering side of the record industry. This is basically how I ended up becoming a disk mastering engineer myself, cutting records with the aim of making them the noticeably better-sounding pieces of art in one’s collection. I wanted to cut the records that I would enjoy listening to myself.

Back then, Günter Pauler was cutting lacquer masters, not DMM, so this is not actually about lacquer versus DMM. Undeniably, both can sound excellent if done with care and respect for the music. But this will give you an idea of who is behind this DMM-Dubplate concept.

In the next episode we shall enter the murky depth of record grooves, in search of the holy grail of analog sound!