Everything That's Audio in audioXpress December 2023

audioXpress December 2023 includes a market overview of multiroom audio, Brent Butterworth writes about new ways to measure ANC earbuds, and Stuart Yaniger measured the new Axign and GaN Systems Class-D audio amplifier board. Richard Honeycutt writes about tubes, BJTs, JFETs, MOSFETs, and ICs, and Dimitri Danyuk, discusses JFETs in audio circuits. Douglas Self explains how to optimize variable-frequency tone controls, and Jan Didden shares his eDD direct-drive amplifier project.

Audient expanded its EVO range of USB-C audio interfaces with the EVO SP8 8-Channel Smart Mic Preamp ada AD/DA converter, a compact unit combining 8 microphone/line inputs, 8 line outputs, and two ADAT I/O connections, allowing it to handle multi-mic recording sessions with ease. Building upon its successful EVO range of audio recording equipment, Audient designed the EVO SP8 to expand the possibilities of its EVO audio interface range for bigger multitrack sessions.

We looked at the most-read articles of 2021 in audioXpress.com (including selected articles from Voice Coil magazine), and we created this Top 10 list of news stories and online articles. 2021 expanded slightly on the record-breaking year that was 2020 for audioXpress.com, in terms of number of visits and regular users of the website. Visitors from all over the world returned more often to read the more than 7,700 stories available. Which of the topics and stories published online in 2021 were the most popular? Here are the results!

This article offers the first serving of an amazing DIY project from amplifier experts Bob Cordell and Rick Savas with an upgrade for the legendary Hafler DH-220 lateral MOSFET power amplifier. The design is implemented on two PCBs, one as a drop-in replacement for the original Hafler circuit board and the other as a new board that consolidates all of the output stage wiring and components within the heatsink and under the main PCB. This article was originally published in audioXpress, July 2021

This article describes the design and performance of a high-quality DC-coupled all-JFET amplifier. The circuit was inspired by John Curl and Erno Borbely designs and was built with readily available junction-gate field-effect transistor (JFETs) from Linear Systems. The input stage is the the complementary JFET differential pair, the second stage is symmetrical differential amplifier with two pairs of opposite polarity JFETs, and the output stage is a complementary source follower. The amplifier can drive loads up to 150Ω. This article was originally published in audioXpress, October 2017.

audioXpress October 2017 brings another strong combination of inside perspective, educational value, and practical projects. In this edition, Christopher Paul explains his Denali Voltage Reference low impedance amplifier design, Stuart Yaniger does a full objective review of the surprising Markaudio-Sota Viotti speakers, we explain how Harman is using COMSOL Multiphysics simulation software on car audio, Richard Honeycutt explains the story of the Circlotron amplifiers and so much more...