This Page is a bit about our MSS Record lathe; what is does and how sound is captured onto a solid vinyl disc.
It was made in 1959 by the MSS company in Reading, England; designed and developed by Cecil Watts . He first produced lathes in the 1930’s and although improvements were made over the years, this one is basically still the same design as the original ones. They had a reputation for being well built and good quality. It still produces a good sound today.
The cutter-head is the focal component of the lathe. Underneath it holds the stylus or needle that cuts a groove into the vinyl disk as it spins
This is a very close up side shot of a diamond stylus, cutting into the vinyl. A thin thread of the cut vinyl is coming off the stylus to the right and up, getting sucked up into the newly added vacuum system. The two wires to the left are part of another new modification; a heating system for the diamond, so that it cuts into the vinyl more easily, like a hot knife would cut plastic more easily.
Although it was designed cut lacquer discs with a ruby stylus, it has been modified to cut finished vinyl records with a diamond stylus. Lacquer disks are made of soft material and are easy to cut into; they are used to make molds for the mass produced harder vinyl disks. A ruby stylus will do to cut lacquer disks but a harder diamond is needed to cut vinyl. {like we do??}
The stylus vibrates side to side in accordance with the vibrations of the inputted sound that needs to be recorded. This makes the sides of the groove being cut wobbly and bumpy: little bumps that match the sound vibrations; a physical record of the sound!
When we put the finished record on the record player and listen back, the stylus picks up these bumps and wobbles in the grooves and vibrates. These vibrations are turned into a fluctuating electrical signal which travels to the speaker, which in-turn vibrates, to reproduce the recorded sound.
{Picture of record player, animation of stylus in groove, wires, speaker}
The overhead motor: This is the motor that moves the cutting arm across the vinyl as it rotates, so the stylus cuts spiral groove and is not repeatedly stuck on the same circle. The varying speed allows to add a wide spaced run in and run out grooves.
{Picture of overhead motor}
{Animation of spiral being made}
Inside the cutter head
I rewound electromagnetic coil inside the cutter head to make the right impedance (resistance) for modern amplifiers (not the old 100 volt amplifiers it was designed for.)
the sound to be recorded travels from the amplifier down the wires as an electrical signal into the magnetic coil and vibrates the armature which in turn moves the stylus. in accordance to the sound input..
{Animation of armature vibrating}
The capstan wheel which controls the speed of the turning platter was set for 78 speed. I got a new one made in a metal workshop by Brian Kepler that is the right diameter for 45 rpm.
{2 photos of capstan}