Direct Metal Mastering (DMM) in Abbey Road's Room Seven

We take a look into Abbey Road’s Room Seven mastering suite, which houses the UK’s only functioning Direct Metal Mastering (DMM) lathe and is operated by engineers Alex Gordon and Alex Wharton.
 

What Is Direct Metal Mastering?

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. Rather than cutting the audio to a lacquer-coated disc, the DMM lathe cuts straight into a copper-plated master disc.
 
 
Perhaps the greatest benefit of a DMM cut in comparison to a standard lacquer cut occurs at the pressing plant, where the copper master bypasses much of the initial galvanics stage required of lacquer masters – meaning not only a faster and more economical process overall, but also less risk of introducing unwanted ticks and pops to the audio. The signal-to-noise ratio is improved, with reduced background noise, especially in shallower grooves. Cutting into a harder metal surface rather than a softer lacquer one also produces more precise transients and a more accurate reproduction of high frequencies – a DMM cut will often sound brighter than a lacquer cut. Furthermore, the harder material reduces the possibility of print-through (where an ‘echo’ of the audio is imprinted into the adjacent groove wall), with a more efficient groove spacing resulting in an approximately 10% longer playing time than standard lacquer cuts.
 

DMM at Abbey Road Studios

Abbey Road mastering engineer, Alex Gordon, who has worked with artists such as Novelist, Sinead Harnett, Yussef Dayes and Rita Ora, is based in Room Seven and uses the Neumann VMS-82 Direct Metal Mastering (DMM) lathe.
 
The nature of the DMM system means it is ideally suited to music that is highly dynamic, with much less noise during quieter sections of audio and a reduced risk of print-through when going from very quiet to very loud moments or vice versa. The increased playing time is obviously a great bonus for cutting more longform pieces. It’s worth noting that while a DMM cut has a slightly different tonality to a lacquer cut, it is entirely subjective which sounds ‘better’. DMM cuts are generally cleaner and more ‘transparent’, and lacquer cuts ‘warmer’.

Lacquers are typically cut deeper than copper, which makes them more suitable for music with a strong low-end presence: a slamming techno record, for instance, you would want to cut to lacquer. Whereas orchestral or soundtrack pieces – I recently cut the entire Lord Of The Rings trilogy soundtrack to copper – or music with a rich or complex top-end is great for a DMM cut. It’s a great advantage to be able to offer both at Abbey Road, so that you can choose the best option for your music.