The Fairchild line of disk recording lathes, first appearing in the early 1930’s, featured a General Electric hysteresis synchronous AC motor, running at high speed, with a worm and gear reduction to drive the platter. While this system in its various permutations in their different models was impressively well made and performed well for its time (see here for a more detailed description and pictures), a direct-drive system with a floor mounted motor is clearly the way to go if the highest level of performance is to be attained.
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.
The AM44 is a Neumann-based lathe, built on original Neumann castings, manufactured around 1944, during the second world war.
The project was founded by Flo Kaufmann, in Switzerland, when he managed to find a pile of these rare beds in the unexplored depth of a warehouse. The plan is to build them up into fully functional disk mastering systems, using newly designed and manufactured parts.
In 2016, Sabine and J. I. Agnew acquired one of these beds, built up and further developed it, into an exceptional quality disk mastering system, which was put to professional service at Magnetic Fidelity.
John Delias, the guitar wizard of the popular rock group "Naxatras", filmed J. I. Agnew while cutting the master lacquer disks, from which the vinyl records of their debut LP were manufactured, at Magnetic Fidelity, and edited the footage to produce this short informative video, offering an insight into this seldom seen, mysterious process.
One might think that the whole issue of absolute polarity for a medium essentially invented around 130 years ago, would have been adequately discussed and standardised by now, leaving no room for further debates. Indeed, it has been, so why bother writing anything further on this topic?
