audioXpress Magazine      July 2021

  audioXpress remains the authority on audio and reproduced sound by connecting manufacturers and distributors with developers, buyers and consultants around the globe! It's readers are the audio product designers, consultants, integrators, DIY enthusiasts, opinion leaders and your best customers. All of them agree that the coverage of trending topics, unique in the audio industry, make audioXpress a must read.

Every month, audioXpress combines the best educational articles on topic such audio electronics, speaker and headphone design, amplifiers (from tube to Class D), acoustics, practical test and measurement, audio engineering praxis, and standards. audioXpress provides inside stories on new audio developments, on R&D Stories, the most complete objective reviews of innovative products and software, and selects some of the best DIY audio projects from worldwide experts.

Comment
4 Editorial: Multiple Ways To Amplify
The potential to offer better performance.
Article By J. Martins, Editor-in-Chief

Features
8 Nuheara IQbuds2 MAX Hearing-Assist Earphones
Digitally Enhanced Hearing Devices
By Brent Butterworth
More than five years in development and after
multiple iterations, Australian startup Nuheara
achieved its goal with the Nuheara IQbuds2 MAX, a
bridge toward truly smart hearables. The design uses
digital technology to bring hearing aid functionality
into true wireless earphones. Brent Butterworth gives
them a listen.

16 NAD Electronics M33 Masters BluOS Streaming DAC Amplifier
The Complete Package for a Wireless Life
By Stuart Yaniger
After reviewing the compact but mighty M10 Masters
Series streaming amplifier from NAD Electronics,
Stuart Yaniger simply had to try the new flagship
NAD M33 Masters streaming DAC amplifier. This was
the first mainstream product to implement the Purifi
Audio Eigentakt (self-clocking) amplifier modules, but
there is a whole lot more to make it a very complete
package for a musical life. The article reviews the
experience and performance measurements.

40 The DH-220C MOSFET Power Amplifier (Part 1)
The Circuit
By Bob Cordell and Rick Savas
This reference DIY project describes an upgrade
construction project for the legendary Hafler DH-220
lateral MOSFET power amplifier, but it can also be
used to upgrade other Hafler models or even inspire
new designs.

50 A New Type of Amplifier for Direct Driving Loudspeakers (Part 1)
Theory Behind the Design
By Paul Marchese
This article describes an amplifier that is a voltage
source at low frequencies, then acts as a current
source at higher frequencies. It can also be configured
to be any ratio of voltage source vs. current source
and/or be frequency independent.

56 Low Distortion Voltage-Controlled Floating Resistor
By Dimitri Danyuk
Learn more about this voltage-controlled floating
resistor project. The circuit consists of a JFET and an
optocoupler with a photovoltaic output, and it can
serve as an effective substitute for the H11FxM Photo-
FET series from ON Semiconductor.

Audio Amplifier Technology And Design Market Update
24 The Multiple Faces of Amplification Evolution
By J. Martins
Addressing audio amplification trends and perspectives, this article highlights products
from different application segments to illustrate the state of the industry.

38 Professional Power Amplifiers
A Market in Recovery
By James Kirby
Futuresource, a leading provider of professional audio market research, publishes market
reports across a range of categories, including loudspeakers, amplifiers, microphones,
mixers, headphones, and more. This latest article discusses the professional amplifier
market and coincides with the release of its new Professional Power Amplifiers Market
Assessment Report 2021.

Columns
Hollow-State Electronics
62 Negative Feedback Amplifier Circuits
By Richard Honeycutt 

Subscribe To audioXpress Magazine
Click here to subscribe to audioXpress magazine.

Previous Issues

2021
January   February   March   April   May   June   July

2020
July   August   September   October   November   December