DMM technology

You are here: Manufacturing > Mastering > DMM technology

Direct Metal Mastering (DMM) is an analogue mastering technique developed in the 80's by two German companies, Teldec (Telefunken-Decca) and Georg Neumann GmbH. Neumann was responsible for the manufacturing of all DMM cutting equipment as well as supplying complete mastering systems until the 90's when the company was no longer active in the record pressing industry. GZ, formally known as Gramofonove Zavody, implemented Direct Metal Mastering in 1985 and shortly afterwards, it become most used mastering technology in GZ. After introducing the new Vinyl Visual Mastering system in 2010, a new era of further development opportunities and improvements of the DMM cutting process began.

The principle of DMM technology

The audio signal coming from the mastering workstation or from a tape is transcribed into a metal master plate through a dedicated DMM cutting head. All modern stereo cutting heads are comprised of two moving coils perpendicular to each other - one for the left and one for the right channel. Movements of both coils are transfered to a cutting stylus with a sharp triangular tip on the end. In the case of DMM, this stylus is specialy made out of grinded diamond and cuts a spiral V-shaped sound groove directly into a high purity copper layer plated on a non-magnetic flat steel substrate. Stampers for record pressing are manufactured directly from such mastered copper plates by a single step electroforming process in electrolytic baths.

Advantages of DMM cutting

  • 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 resulting in longer playing times
  • only one subsequent electroforming step
  • more stampers from one copper plate without damage being caused to the plate
  • DMM is suitable for both standard LPs as well as high quality audiophile 45rpm records

GZ Vinyl is the only place in the entire world operating 3 DMM lathes for production of vinyl records:

DMM Studio 1

  • Neumann VMS-82 cutting lathe upgraded for VVM
  • Neumann SAL-84 modified amplifiers
  • Neumann SX-84 cutting head
  • Neumann SP-79 mastering console with new control panels for VVM and A/B analogue signal paths
  • JBL 4343 studio monitor system
  • Top quality PrismSound Orpheus audio interface for DA/AD conversions
  • Telefunken M15A tape player with playback and preview heads
  • Technics SL-1210 MK2 direct drive turntable for playback of test pressings

DMM Studio 2

  • Neumann VMS-82 cutting lathe upgraded for VVM
  • Neumann SAL-82 amplifiers
  • Neumann SX-84 cutting head
  • Neumann SP-272 mastering console with direct analogue cutting possibility
  • GZ made control console for the VVM workstation
  • JBL 4343 studio monitor system
  • Top quality PrismSound Orpheus audio interface for DA/AD conversions
  • Telefunken M15 tape player with playback and preview heads
  • Tesla NC 440 direct drive turntable for playback of  DMM plates & test pressings

DMM Studio 3

  • Neumann VMS-82 cutting lathe upgraded for VVM
  • Neumann SAL-84 amplifiers
  • Neumann SX-84 cutting head
  • GZ made control console for the VVM workstation and  with VU meters and a NTP meter module
  • JBL 4343 studio monitor system
  • Top quality PrismSound Orpheus audio interface for DA/AD conversions
  • Studer A820 Master recorder for high quality tape-PC digitization incl. Dolby SR/A, dbx and Telcom C4 processors
  • Tesla NC 440 direct drive turntable for playback of  DMM plates & test pressings

Gallery

  • 01 Enhanced Neumann mastering console
  • 02 Copper plate inspection
  • 03 Senior cutting specialist Mr Kuss explains DMM cutting
  • 04 Grooves in a microscope
  • 05 Copper plate and DMM head during cutting
  • 06 Copper shavings after cutting
  • 07 DMM head - bottom view
  • 08 Real-time DMM cutting in a side microscope
Photo gallery