A2B Audio Bus: Two Alternative Power Schemes

In the second article about the latest generation A2B technology from Analog Devices - expanded with the release of the AD2437 chip - Brewster LaMacchia explores the latest possibilities for audio applications in many other areas other than automotive audio. After reviewing the three generations of A2B technology, LaMacchia expands on the alternative power schemes that deserve some investigation for multichannel digital audio applications. This article was originally published in audioXpress, August 2024.

Series voltage regulators are a great way to provide almost-noise free and rock-stable DC to your audio circuits. But the load current often has distorted signal components that can generate a ‘dirty ground’ across the supply ground wires and tracks. This can introduce distortion components in other circuit sections using this ground. With shunt regulators we can keep the dirty ground localized and largely avoid the problem. Technical Editor Jan Didden explains.

Regulator Needed for Stable, Noise- and Ripple-Free DC Relationship. Does your nice circuit get what he needs from the power supply? Jan Didden explores when a regulator is a regulator. ...when it regulates, you’d think. Yet, in many online fora and discussions you see circuits that ‘do something’ but there’s absolutely no regulation taking place.

Audio amplification solutions company ICEpower announced availability of its latest 1000S power supply, filling a gap in the company's portfolio for high-power amplification equipment. Based on the resonant LLC converter of the tried and tested ICEpower 700AS1 module, the new 1000S offers a stable and consistent power supply solution in a compact format to pair with the company's 300A2 and 400A2 modules for applications in hifi, commercial amps, whole home audio and active speakers.

GaN Systems extended its lead in Class D GaN-powered audio with the release of two complete Class-D high-performance GaN FET amplifier boards and two complete audio boost converter solutions for marine, auto, and battery-powered vehicles. GaN Systems now provides a comprehensive solution of turnkey amplifier designs, power supplies, and boost converters — allowing audio systems designers across automotive, home, and professional markets to mix and match designs to maximize performance for specific applications.

There's a lot of everything in audioXpress October 2022. Starting with a market update on audio for Residential Integration. Next, Jonny McClintock shares The Story of aptX, Gary Galo reviews Sumiko phono cartridges and new 78 rpm stylus, Richard Honeycutt explains RT Measurement, Frans de Wit tackles the design of a DC Power Supply, Ken Bird builds a pair of tower speakers with Oaktron drivers manufactured in the US, and Christopher Paul writes about Triode Common Cathode Stages and its controversies.

For those readers following the fascinating article series by Morty Tarr on "Cascodes, Folded Cascodes, and Current Mirrors," this final article in the series contains an additional section with important aspects of amplifier design. In the first two parts of this article series, Tarr discussed the technical merits of cascodes and related circuits. This useful addendum covers a simple test circuit for matching FET devices, the fascinating story of the Blowtorch Line Stage design, and additional notes on inverting and non-inverting amplifier stages and integrators. This article was originally published in audioXpress, December 2021.

Great articles, practical projects, reviews, and audio technology previews start the year in full force! That's what our readers will find in audioXpress January 2022, starting with an update on new materials and engineering approaches for loudspeakers, and articles by Charlie Hughes, Scott Dorsey, Frans de Wit, Ken Bird and Mike Harkins. Brent Butterworth reviews the Olive Pro earbuds, while Raj Senguttuvan from Knowles discusses differentiation for True Wireless Stereo (TWS) design and development.

Texas Instruments (TI) introduced a new family of synchronous DC/DC buck controllers that enable smaller power-supply solutions with lower electromagnetic interference (EMI). Featuring an integrated active EMI filter (AEF) and dual-random spread-spectrum (DRSS) technology, the LM25149-Q1 and LM25149 enable designers to cut the area of the external EMI filter in half, lower the conducted EMI of the power design by as much as 55 dBµV across multiple frequency bands, or achieve a combination of reduced filter size and low EMI.

In this second article, Brian Lowe (Belleson LLC) continues his search for the Unicorn of "Measuring Voltage Regulator Ripple Rejection," this time focusing on the test fixtures. Testing a voltage regulator with exceptionally good performance requires an even more exceptional signal source and measurement setup to measure sub-microVolt ripple across a wide frequency range. Complementing the final article, Jan Didden, offers an informative sidebar about super regulators. This article was originally published in audioXpress, June 2019.