coil winding ⁽⁴⁾

Presto 1-D Cutter Head Feedback Modification

December 26, 2019 by J. I. Agnew

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.

Rebuilding an Audax R-56 Cutter Head with Feedback

December 24, 2019 by J. I. Agnew

This Audax cutter head arrived with a fried coil and a completely crusted armature. The damping material had not aged well.

A complete disassembly, cleanup and reassembly would be required, with the renewal of the damping material and drive coil. This was yet another perfect candidate for our feedback modification.

Neumann MS-52H Cutter Head with Feedback: Repair and Hot Mods

December 11, 2019 by J. I. Agnew

This Neumann cutter head arrived as a particularly clean example, but in need of repair. The first obvious issue was that the coil was fried.

The second issue was that the original stylus fitting was broken.

Precision Transducer Development

June 7, 2019 by J. I. Agnew

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.