Jump to: navigation, search

Difference between revisions of "DMM"

(Created page with "'''DMM''' stands for '''Direct Metal Mastering''' and is one of two existing technologies to create original (master) discs needed for vinyl records pressing. The other, older...")
 
Line 1: Line 1:
'''DMM''' stands for '''Direct Metal Mastering''' and is one of two existing technologies to create original (master) discs needed for vinyl records pressing. The other, older technology in a "microgroove" era of phonograph records is cutting into a lacquer disc. Majority of our vinyl production is done using DMM, but lacquer cutting and/or processing of a supplied lacquer is available on request.
+
'''DMM''' stands for '''Direct Metal Mastering''' and is one of the two existing technologies to create original (master) discs needed for vinyl records pressing. The other, older technology in a "microgroove" era of phonograph records is cutting into a lacquer disc. Majority of our vinyl production is done using DMM, but lacquer cutting and/or processing of a supplied lacquer is available on request.
  
 
== History ==
 
== History ==

Revision as of 16:55, 13 February 2020

DMM stands for Direct Metal Mastering and is one of the two existing technologies to create original (master) discs needed for vinyl records pressing. The other, older technology in a "microgroove" era of phonograph records is cutting into a lacquer disc. Majority of our vinyl production is done using DMM, but lacquer cutting and/or processing of a supplied lacquer is available on request.

History

DMM was developed and issued in 1982 by a collaboration between two German copanies Teldec and Georg Neumann GmbH.

Neumann was exclusively supplying the technology and mastering systems until mid 90' when the company left the industry during decline of popularity for vinyl records.

There are about 12 DMM cutting lathes operating in the whole world that produce masters for vinyl records manufacturing.

Interesting trivia: two DMM cutting lathes have been obtained by Church of Scientology, which supposedly use them to record speeches of their founder L.R.Hubbard and put those into "time-capsules" together with spring loaded phonographs. So, if someone digs and opens such capsule after a predicted apocalypse, they should be able to listen to Mr. Hubbard speeches without the use of electricity.

Even with the resurgence of vinyl records, no one has been able to manufacture a brand new DMM cutting lathe since their original batch in 1980'es.

DMM Principle

DMM transcribes audio coming from a workstation or a master tape into a copper plate using a diamond cutting stylus (the copper that is being cut into is plated layer on a non-magnetic steel substrate). This creates an original "positive" (mother) disc that is used to create a "negative" stamper in an electroforming galvanic process. Stamper is then attached onto a pressing machine and is used for a mass replication - pressing of vinyl records.

In comparsion with lacquer cutting, lacquer is cut into a nitrocellulose layer coated on an aluminium disc using a heated sapphire cutting stylus. Because nitrocellulose is not electrically conductive it needs to be sprayed with a thin layer of silver in order to be usable in a later electroforming galvanic process. We use traditional lacquer processing in galvanics which includes three copies: "negative" (father), "positive" (mother), "negative" (stamper). Lacquer itself is consumed and discarded in the process. Lacquers should also be sent for processing as soon as possible so the grooves cut into the soft nitrocellulose surface do not degrade due to heat and environmental conditions, typically resulting in a loss of high frequencies.

Team DMM -vs- Team Lacquer

DMM and Lacquer cuts each have their own fans and supporters. Please note that neither technology is no way a replacement for a proper mastering and recording process and all pro/cons of each technology can only account for the transcription onto a vinyl record as a physical medium.

DMM supporters typically list these advantages:

  • more accurate reproduction of high frequencies
  • less background noise, better signal-to-noise ratio
  • reduced print-through sounds (pre-echo) between adjacent grooves
  • no groove wall bounce-back effects after the cutting (improved transient response)
  • more efficient usage of the total available record surface (longer playing times are available)
  • only one subsequent electroforming step

Lacquer supporters typically list these advantages:

  • bigger vertical amplitudes which can carry more out-of-phase low frequency signals (e.g. a bass quitar or a kick drum placed only in one channel)
  • wider and deeper grooves which are more tolerant for most kinds of surface damage
  • the softer lacquer material allows very high cutting levels resulting in louder records

Please note that higher volume and bigger vertical amplitudes also involve a higher risk of distortion and mistracking on some turntables.

VVM mastering, improvement to DMM cutting process

VVM (Vinyl Visual Mastering) is a state-of-art computer simulation of the mastering process that allows setting up cutting parameters and simulating the cutting process before the actual cutting is performed. This allows for these main critical features:

  • A very accurate virtual simulation which will find critical parts in supplied audio before the actual cut. Every cutting system needs to employ protections against critically high electrical current or critically high acceleration of the cutting stylus to avoid damaging the cutting head or stylus. In many cases this is done using a limiter placed in the signal chain right before the signal is fed to the cutting head. Simulating the cut allows to address these critical conditions in a more controlled manner.
  • Each order has individual settings, which can be adjusted for arbitrary parts of audio. There is a direct two-way communication between the computer and the cutting lathe
  • Differential sound and graphic analysis can play or show differences between original audio and processed signal, feedback or vinyl record signal.
  • Vinyl measuring system - geometric, physical, dynamic and load measurements in time or frequency domain.
  • Groove processor - controls track pitch, groove width and warps audio signals to compensate possible cutting and playback distortion. Every cut can have a different track pitch strategy.
  • Mathematical model of stylus and groove – the software computes a virtual groove based on geometric dimensions of a defined cutting stylus and can compare it visually with a real groove photo from a microscope.
  • High quality non-destructive signal processing with unique vinyl algorithms. The original audio data remains untouched for a future use.

Summary

If you are mainly familiar with lacquer cuts and would achieve similar level of loudness with DMM, please specify that you would like to order a LOUD CUT during your order processing (please note that this is directly related to a possibility of higher distortion level in loudest parts of the recording). If you have a studio or a mastering engineer that supplies you with lacquer cuts you like, please state that you would like to use a supplied lacquer during your order.

In any case, if you are unsure, please add test pressings to your order to make sure you are okay with the sound before moving on to the main pressing.