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Repairing a Westrex 2B cutter head

Some time ago we were asked to repair a vintage Westrex 2B feedback cutter head.
As with all Western Electric and Westrex products, their cutter heads were beautifully made and represented the state of the art in their time. Not only did they sound great, they also looked aesthetically pleasing, with curved lines that were not a trivial task to manufacture, in the days before CNC machine tools, CAD software and pocket calculators!

New line of high precision machine spindles now available

A good machine spindle is one of the factors defining the accuracy attainable from rotating machinery. This applies equally to machine tools used in industrial manufacturing and to disk recording and mastering lathes, used to make phonograph records.

At Agnew Analog Reference Instruments, we use some of the finest and most accurate industrial manufacturing machine tools ever made, to build some of the finest and most accurate disk recording and mastering equipment ever made, so we have had to learn a thing or three about machine spindles along the way.

Presto 1-D Cutter Head Feedback Modification

Presto 1-D and 1-C cutter heads are frequently encountered on our lab bench for repair and restoration. Some are just regular repairs to original spec, others are rewound to a different impedance, but some undergo more comprehensive and exciting modifications!

We have previously examined modifications where a feedback system was added to a Neumann MS-52H and an Audax R-56 cutter head. This time, we shall discuss adding feedback to a Presto 1-D, which arrived with damaged coils.


A Fashionable Rek-O-Kut Lathe Cabinet

Have you ever noticed the total absence of audio equipment from the luxury houses presented in glossy architecture and interior design magazines? It makes the inhabitants of such property come across as rather uncultured.

In fact, not only is an audiophile grade sound system a minimum requirement for the home of anyone affluent enough to hire an interior designer, but it is important to choose a designer who can appreciate the aura of sophistication and intellect projected by a beautifully restored vintage disk recording lathe, set in a handcrafted custom cabinet, in a conspicuous corner of the living room!

Presto 75A: 50 Hz 33 1/3 and 45 rpm Conversion

It would appear that 50 Hz conversions of vintage "made in USA" disk recording lathes are becoming rather fashionable! Last week we examined how we converted a Rek-O-Kut Model V by machining a new capstan and making a special transformer, Type 1760.

We have done 50 Hz conversions (and even some 60 Hz ones!) on many different lathes and turntables, using all of the possible methods of doing so: New rubber rollers, new capstans, new belt pulleys and even electronic frequency conversion (Agnew Analog Type 191 frequency converter) for professional disk mastering systems.

This week, we will have a look at the Presto 75A, a high quality machine, dating from the 1930's, which was even used by the BBC as a broadcasting turntable!

Precision Motors and Control Systems for Leadscrew Automation

Depicted here, are two external rotor, polyphase, electronic commutation motors, fitted to custom mounting plates, ready to be installed in disk recording systems, to control the leadscrew.

These are very high precision motors, with features allowing accurate, closed-loop control of speed over a wide range, as well as positioning applications. A combination of hall sensor arrays and high resolution encoders makes them extremely versatile, compatible with a wide range of lathes.

New Agnew Analog Product Plates

We are very excited to present our new product plates, featuring our new logo, engraved on stainless steel plates!

The new logo was designed by Sabine Agnew and the choice of stainless steel as a material for the plates acts as a further statement of our commitment to exceptional quality, to accompany our products throughout their extremely long service life with no deterioration.

Precision Transducer Development

This item is the latest addition to our collection of experimental transducer prototypes. What you see is a multi-layer miniature winding on a custom machined former, entirely made in-house at the Agnew Analog Research & Development Laboratory.

 

Restoring Vintage SME Tonearms

Over the past few years, we have restored a number of SME 3009 and 3012 tonearms, covering most of their variants made over the impressively long production life span of this model range.

This outstanding tonearm was first introduced in 1959, setting a standard for high performance tonearm design which is still hard to beat, 60 years later.

We have used our restored SME tonearms on a large number of reference reproduction systems, for our own use and for our customers, such as the Thorens TD160 project which was presented here last February. These systems are excellent for Quality Control in vinyl record manufacturing, to ensure that any defects are caught early.

They are of course also capable of offering an intensely enjoyable, accurate listening experience, coupled with an accurate cartridge.

Lab Report: The Agnew Analog Stereophonic Cutter Head

Happy new year! Time to reveal what has been secretly developing in the lab throughout the past year: A stereophonic cutter head of an entirely unique design, invented by J. I. Agnew during his work with experimental transducers for measurement and testing purposes.

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.

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.