Moving-magnet pick-up processor

Introduction

Fabricants of moving-magnet pick-up elemenents often give their elements a little mechanical resonance at circa 18 kHz as to improve the high-frequency response. Unfortunately, this hurts the phase response in this frequency area.

The pick-up pre-amplifier described here contains a resonator that has the same characteristics as the mechanical resonance of the element. The electronic resonator is then used to create an amplifier with the inverse mechanical resonant response of the pick-up element. This restores the proper phase response.

The idea and design of the pre-amplifier is based on the following publication: Signaalprocessor voor magneto-dynamische pick-up elementen. Radio Elektronica nummer 19, 18 oktober 1980, pagina 39-53.

The following schematic is the original design for the Shure M 95 G-LM element.

Here is a version for the AT 3200 XE II element.

Martin Moene Electronics Department · Leiden Institute of Physics · Leiden University