Pre echo is caused by the cutting stylus unintentionally transferring some of audio signal into the previous groove wall causing a faint audio signal a pre echo.
Dmm vinyl cut.
Rather than cutting the audio to a lacquer coated disc the dmm lathe cuts straight into a copper plated master disc.
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.
There are many technical reasons why dmm is but i won t bother going into them here but given that abbey road and so many others have gone back to lacquer it s clear that most current vinyl producers prefer lacquer.
Dmm did though eliminate the problem of pre echo sometimes audible on a lacquer.
Direct metal mastering dmm is an analogue audio disc mastering technique.
Another argument for the use of dmm is that it removes the need for one stage of the galvanic process.
Direct metal mastering dmm is a system of vinyl cutting developed by neumann and teldec telefunken decca in germany during the 1980s in an attempt to increase the reliability of the cutting and pressing process and circumvent some of the common problems that can occur with conventional lacquer masters.
Often the reason for playing a vinyl record is to have the warm and analogue sound that is often not present in a dmm cut.
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.
Unlike conventional disc mastering where the mechanical audio modulation is cut onto a lacquer coated aluminum disc dmm cuts straight into metal copper.
Which was more accurate.
The fact the groove is cut to copper a hard metal and not to soft lacquer nitrocellulose supposedly endows dmm vinyl lp with a very different tonality to traditionally manufactured vinyl lp pressings.
