Pressing

If, however, you are not happy with the test pressings, then we need to find out what is actually wrong with the sound or identify any other possible problems. If the problems have occurred due to error on GZ Media’s side, we will produce new metalwork (stampers) or re-cut the test pressings using a new master (if required). If the fault is on the customer’s side (due to a badly prepared master source, for example, badly cut lacquer foils or incorrectly manufactured metalwork parts supplied by the customer), then the customer will be liable to pay for new process, should they require new test pressings.

Surprisingly enough, the production of vinyl records is one of the most accurate and precise amongst all methods of mass production. The finest details carried in the grooves which contain the sound information are more than a thousand times smaller than the width of the groove itself, which can be compared to the thickness of a human hair. Even though we cannot see these details, even under a microscope, the sound is reproduced very accurately by high-quality playback needles. In addition to the quality of the actual pressing material, it is extremely important that the records are handled with care and kept clean when being handled and listened to.

The basic material used in the production of vinyl matter is a powdered copolymer of vinyl chloride and vinyl acetate which is mixed in a fluid mixer with the necessary additives. Stabilizers are added to prevent degradation at higher temperatures as well as lubricants - so that the matter adheres to the pressing tools,  a moderator melt flow which adjusts the speed of the flow between the stamper material during pressing and finally, the colour. Classic black records are made from a special black carbon while coloured records are produced using basic colours. We are also mixing several varieties of basic dyes or pigments to create special colours or shades of colours. The resulting powder for creating the pressing matter is  piped through special systems which lead to the presses through extruders. When the material comes out of the extruder, its temperature is approx. 165-170 degrees. The matter is kneaded, homogenised and dispensed directly to the pressing machine. It is also possible to use granulated vinyl matter in the extruders.

The technical quality of the audio recording requires special attention. With the current volume of production, the diversity of musical genres and the effects used in sound production, traditional methods of control based on listening and subjective evaluation can fail. Not only because they do not have enough capacity to cover production, but mainly they do not allow to clearly distinguish any unintended noise coming from the production process that differ from those contained in the original record. We have therefore developed our own control system and software, which forms part of our unique VVM system and objectively evaluates the differences between the recording on the record and the substrate used to produce each matrix. The recording from the samples taken from the production is recorded on computers on automatic robust turntables with calibrated reproduction electronics and equipped with high-quality ORTOFON recording systems. Powerful computers then compare each record with the appropriate starting material and evaluate the differences found. The result is an objective report on the quality of the audio recording on each individual inspected side. It contains information on the type and frequency of detected differences or defects, their classification according to the degree of severity and their distribution on the record surface and many other important parameters. The software then allows the inspection staff to quickly find each individual detected difference - without manipulating the record or the initial substrate, listen to it and confirm, or even correct its classification. Any decision to resume production, release for shipment or order to dispose of defective production is based on reliable information that is not burdened by subjective influences. Statistical processing of information in the medium and long term then helps to reveal hidden connections and contributes to the improvement of technology.