Joachim Gerhard on Low Noise Phono Stages: The Discrete INA Design

Ask audio industry insiders and audiophiles alike about Joachim Gerhard, and chances are that they mention the many high performance speakers he designed over the years. But he also has a great track record designing phono preamps and this interview explores that aspect of Joachim’s career. In this second part of the interview, Jan Didden explores Gerhard's design ideas and goes into details on his Discrete INA design, a discrete input stage instrumentation amplifier topology.

Read the extended Show Report of the 5th International AES Conference on Automotive Audio. Santiago Rayes (GRAS Acoustics) explains the latest advances in Measurement Microphones for Automotive Testing. Reinhold Lutz writes about Eliminating Speaker Doppler Distortion, René Christensen shares an exercise of Double Bass Arrays, and Joerg Panzer (R&D Team) and Patrick Macey (PACSYS) share their Experimental and Theoretical Investigation of an Unusually Shaped Horn. Jan Didden reviews Bob Cordell’s latest book, “Designing Audio Circuits and Systems”.

There's a lot of knowledge in audioXpress September 2024. There's a residential installation and home theater Market Update, and a review of the Dayton Audio iMM-6C USB-C Test Microphone. George Ntanavaras shares what he learned using AKABAK simulation software, and Charlie Laub explains all about Derived from Elliptic crossover filters. Read Jan Didden's interview with Joachim Gerhard discussing Low Noise Phono Stages, and learn how to build a Moving-Coil Phono Preamp designed by Sam Dulaney. And much more.

audioXpress traveled to Germany to learn about the Pure Acourate Sound Project, which aims to create the lowest distortion sound in a listening room. The initiators of the Pure Acourate Sound project are Ulrich Brüggemann, Markus Grelka, and Ralf Höllmann. The partners involved in this unique system are Purifi Audio, Okto Research, GIK Acoustics, Klippel, Roon, AudioVero, Rose Handwerk, and Joachim Gerhard. Ahead of the presentation at the May 2024 Munich High-End show, audioXpress offers a preview of the project.

In the 2024 Glass Audio Special issue there’s Menno van der Veen’s TubeSociety TS-2022-OTL hybrid amplifier, and a Low-Feedback Triode Amplifier With Zero Output Impedance (ZOI) as DIY projects, designed by Tim Mellow and Peter Farrow. More great audio electronic articles by Rudolf Moers, Christopher Paul, and Dimitri Danyuk. Read about sustainable acoustical absorption, the Pure Acourate Sound Project, and The Neurochrome Story. And Andrew C. Russell concludes his High-Performance 60-Watt Class A Amplifier project.