Working together with Eric on upgrading his Scully Disk mastering system, Sabine grabbed the chance to give our readers a little peek into the head of an experienced mastering engineer. Eric Conn works together with Don Cobb and a small Dog called Chaco at Independent Mastering in Nashville, Tennessee.
This beauty is a fully restored and extensively modified, vintage Scully lathe, operated by Eric Conn at Independent Mastering, in Nashville, TN.
It started life in the 1940's as a completely manual machine. A sturdy design, capable of very decent results, these lathes were extensively used across the USA and other parts of the world for several decades. Many are still in operation today. In the original condition, they were quite limited in what they could do. But, as with most good lathes, they can take a lot of modification and improvement.
There is a long history of use of precious stones as industrial materials, from precision bearings to cutting tools, lapping compounds to grinding tools and several other specialised applications.
The recording of phonograph records is essentially a machining operation, performed by means of a machine tool called a disk recording lathe. A special cutting tool is used to cut a continuous spiral groove on the surface of a blank disk. This tool is called a disk recording stylus, or simply cutting stylus. The big difference to other forms of machining is that there is sonic information stored as modulation of the cut groove, which can be reproduced on another special machine, often called turntable or record player, or disk reproduction system.
In the previous episode, we had a look at taper shank stylus adapters and saw a vintage magnetic monophonic cutter head fitted to the AM44 lathe. The two are not normally compatible. Neumann lathe suspensions do not have the same mount as the suspensions of Presto, Fairchild, RCA and other lathes of the monophonic era, which were originally designed to accept such cutter heads.
But, in fact, almost any cutter head can be fitted to any lathe, as long as there is enough space for it to physically fit, by means of a suitable adapter. The eagle-eyed reader will probably have noticed that the cutter head mount on our prototype AM44 suspension is similar to, but not the same as, the mount used in Neumann suspension boxes. So, the adapter shown here was made specifically for our AM44 suspension unit.