disk mastering (18)

Agnew Analog Type 6016 Scribing Platform

The Agnew Analog Reference Instrument Type 6016 is a fully adjustable scribing platform that will work on any make and model of lathe of any vintage, with a 16", 14", or 12" platter, for 14", 12". 10" or 7" records. Scribing platforms are typically used by mastering engineers, to rest their hand while scribing the catalog number, their signature, or secret messages, in the land around the lead-out groove spiral, without touching the surface of the fragile lacquer master disk. Remember, it is your signature that should be proudly displayed on that master disk, not your fingerprints! Significant quantity discounts available, especially on orders over 100 pieces. Please enquire for details.

 New Hydrodynamic Oil-bath Bearing Units Available Now!

For many long years, J. I. Agnew has been examining, adjusting, repairing and replacing bearing systems of all kinds, from disk recording lathes and turntables to tape machines, high precision machine tools, measurement instruments, industrial equipment and all manners of motor vehicles, from passenger cars to heavy trucks. Over the past few years, he has designed and machined countless bearing units to replace worn or damaged units on a diverse range of disk recording lathes and machine tools. Valuable experience was gained, which along with his solid engineering background, was put to good use in improving his designs further and further, up until the current stage of development was reached.

The Reliable Stylus Heating System: Type 192

The Agnew Analog Reference Instrument Type 192 is a minimalist, industrial-grade stylus heater supply unit, designed and built to last forever.
It is a current-regulated design, set at the factory for 550 mA, in an ultra-ruggedized configuration, for maximum reliability in constant-duty environments, when downtime is not an option.

Direct-Drive Conversion on a Fairchild Lathe

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.


Type 1501 Stylus Shank Adapter gets a Flat!

Our popular Agnew Analog Reference Instrument Type 1501 Stylus shank adapter was intended to make it possible to use the Neumann-style taper shank stylus (Transco 320, Adamant NSH-2, etc) with vintage mono heads such as the Presto 1-C and 1-D, which need a long shank stylus.

Up to now, customers would just install the adapter and leave it there, only occasionally replacing the stylus. One customer, however, wanted to be able to leave the stylii aligned in the adapter, and change them out without needing to realign.

School of Cut - Learning how to cut records at Agnew Analog

We recently had the pleasure of having Symatic over, from Bristol, UK, for a week of training on how to cut (and how not to cut) records.

Symatic runs Cut & Paste Records, a record label attracting some serious attention among skratchers, with high quality releases of skipless skratch samples, lock-groove tones, beats, and relevant music.

Motional Feedback Disk Recording System Design

 

In 2015, J. I. Agnew started developing a high-end cutting amplifier for disk mastering systems, to be used with motional feedback stereophonic cutter heads. During this process, he investigated the design and implementation problems of such transducers in great detail. As usual, he documented his progress, which evolved into an engineering report, titled "An Investigation of Motional Feedback Disk Recording System Design", which was accepted for publication in the November 2018 issue of the Journal of the Audio Engineering Society, following the customary peer review process.

Scully Lathe Restoration and Modification

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.

Precious Stones for Cutting Precious Records

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.

Lab Report: Cutter Head Mounting Adapters

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.

Lab Report: Making cutting stylus shank adapters

Stereophonic cutter heads developed by Neumann are designed to accept a cutting stylus with a conical shank, resembling a micro-miniature version of a Morse Taper, a type of fitting frequently encountered in machine tools, especially metalworking lathes. Vinylium and FloKaSon cutter heads also adopted the same fitting for the sake of compatibility. But most other cutter heads, especially all those predating the stereophonic era, used long, thin cylindrical shanks, often with a flat machined on one side, to allow a set-screw to align the stylus and secure it in place.

The AM44 Disk Mastering Lathe Project

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.