From the recording to the record

Just before the birth of a record: The extruder has melted the PVC, which has now been placed between the pressing molds (center of picture). In the next step, the pressing plates, which have been tempered to 140 °C, slowly close with 110 tons of pressure. Pressing an LP takes about 30 seconds.

On the left against the wall are two automatic presses that eject a long-playing record every 30 seconds. A new single already falls onto the spindles every 20 seconds. So between 120 and 180 records are possible per hour. A higher output is not practical - if quality is required. The machines hiss and clack incessantly. With an impressive choreography, transport arms, cutting tools and other levers move until the black, red or even violet records are placed on the spindles one after the other. The largest part of the room is taken up by tables on which large stacks of records, sleeves, labels and covers lie. Employees are busy putting the records into their sleeves and then making them ready for customers. Without hustle and bustle and very carefully, but efficiently. Before entering the recording studio, there is an urgent note: be sure to turn off your cell phone! Because if the cell phone should even just report to a radio cell, it would render the recording in progress unusable.

Mourad Gerlach is the sound engineer and sits in front of two large screens, in a perfect stereo triangle, between two high-end speakers mounted on tripods. He is intently examining the soundtrack of the current recording. To his right is a turntable ready for testing, to his left is the actual lacquer foil cutting device. Behind it, there is even a tape machine - for all customers who insist on a completely analog recording chain. The cutter dates back to the seventies - classic, solid mechanical engineering for eternity. The manufacturer at that time was the company Georg Neumann GmbH. It has great similarities to an oversized and overly stable record player, but works in exactly the opposite way. The so-called graver converts the analog sound signal into physical vibrations and cuts them into a thin nitroacetate lacquer film. This in turn is applied to an aluminum disc for stability. Negative pressure ensures that the recording disc lies absolutely flat on the solid platter. The result of the procedure is the so-called master cut.

The analog signal for the cutting machine (left) is usually generated via a high-quality digital process. But an analog tape machine is also available if required.

The production of these lacquer films is anything but trivial, because the nitroacetate lacquer is extremely flammable and highly explosive. Until recently, there were still two manufacturers of these coating films in the world - until the plant in the USA was destroyed by a huge explosion in early 2020.

A critical factor in the production of the paint films is that the aluminum sheets have to pass through a curtain coater. This produces large quantities of highly flammable vapors. These must not come into contact with anything that has sufficient ignition energy - certainly not with the heating coils that ensure accelerated paint curing in the immediately following drying zone. "The entire board industry is now dependent on the one plant in Japan," Sudau explains, and you can tell he's not unconcerned. "The plants date back to the seventies and I'm afraid that nowadays it will be extremely difficult and, above all, uneconomically expensive to set up such a plant and, above all, to obtain an operating license in the first place." Presumably, therefore, the whole industry would sleep better if there were an alternative to the nitro-acetate paint. But as is so often the case, not only in surface technology, it is extremely rare for an optimally functioning substance to have an equally good twin that does without the negative properties.

In any case, the requirements for a coating suitable for Mastercut are high and varied. The surface must become perfectly smooth and there must not be even the smallest air pockets after drying. This is because the graver could open up such air pockets during the cutting process. When playing the record, either the needle would then break off later or at least a grenade-like noise would be produced. In addition, the lacquer must not be brittle, so that chipping occurs during cutting. But also too soft would be fatal, because then the graver would remove too much material and thus ruin the recording. So finding an alternative is more than just challenging.

The mastercut is cleaned and activated in three baths to ensure flawless silver plating in the next step.

From film to pressing tool

Before a record can be pressed, a pressing mold, the so-called stamper, must be produced from the sound recording in several steps. This is subjected to very high stresses, as it must withstand 110 tons of pressure and 140 degrees Celsius in the press.

After the mastercut is finished, the electroplating part begins. The sound recording is pretreated in three panning baths. Dieter carefully slides the black sound carriers into the trays in a concentrated manner. The first one contains an alkaline cleaner, RBS 35, for non-corrosive materials, which can be rinsed off without leaving any traces. This is followed by saponin as a rinse aid. The sensitizing solution, a nickel fluoride-hydrochloric acid mixture, is the final step. It is critical for the subsequent silvering process and is therefore prepared daily. The swiveling device for the baths was developed in-house. Between each bath, the mastercuts go on a pickup device into a large tub and Dieter thoroughly rinses them with a Gardena shower - using desalinated water. There's no timer running, but the rinse times seem almost constant. "I've got the feel of it by now," he grins. Things get spectacular when it comes to silver plating. Dieter hangs the black disc on a rotating plate in the silvering booth. Then he takes the somewhat bizarre-looking two-nozzled gun and sprays slowly from the edge inward. The spray is colorless, then suddenly after a few seconds the color of the mastercut turns from black to shiny silver from the outside to the inside. After rinsing with desalinated water, a shiny silver gem hangs in the spray chamber that could easily be hung on the wall as a silver record.