You can DIY! Build an Audio Dummy Load

An audio load is an essential piece of test equipment for any audio electronics workshop. Having created the very popular Heathkit ID-5252, more than 35 years ago, Gary Galo decided to design a new option for everyone to build now. The ID-5252 contains four 8Ω, 60W power resistors. The biggest limitation of the Heathkit load is power handling. Series and parallel combinations can be used to produce various resistances and power levels — up to 240W at 8Ω, using all four resistors. But, simultaneously testing both channels of a high-powered amplifier requires two ID-5252 units. Fortunately, the raw parts for building an audio load are easy to find.

Longstanding audioXpress author Gary Galo reviews the latest Sumiko Olympia and Wellfleet phono cartridges, and RS78 78 rpm stylus. The new RS78 is Sumiko's first 78 rpm solution, meeting the needs of many vintage recording enthusiasts and can be installed on many of the brand's cartridges. In this review, Gary discusses the merits of these versatile and high-quality cartridges while exploring his personal collection of 78 rpm recordings. This article was originally published in audioXpress, October 2022.

Linear Audio, the bookzine created in 2010 by Jan Didden, is now available on a USB with The Complete Linear Audio Library. We asked three Linear Audio and audioXpress authors - Gary Galo, Bob Cordell, and Dimitri Danyuk - to review it and share their thoughts. Important to know, the USB drive doesn't contain only the PDFs of published articles. It also ads additional articles by Jan Didden and others, together with materials of historical interest.

Ending the year with great content, as we do 12 times per year, audioXpress December 2020 is now available in print and online. In this edition, we pay tribute to Jeff Bagby, explore the QuantAsylum QA401 audio analyzer combined with the new QA451 programmable load, and explain the process of measuring wireless audio products using multi-tone testing. Plus, Brewster LaMacchia expands on A2B designs, Gary Galo details how to improve low-output moving-coil cartridges with his Jensen-based step-up transformer, and Mike Harkins reviews the versatile Puffin Phono DSP by Parks Audio. And much more, now available!

Gary Galo reviews GeerFab Audio’s D.BOB Digital Breakout Box, a valuable new solution for all the music enthusiasts who would like to listen to their Super-Audio CD (SACD) music collection by feeding the DSD datastream via HDMI from the player to an outboard digital-to-analog converter (DAC) in high-resolution audio. And GeerFab Audio created the first device that delivers! This article was originally published in audioXpress, October 2020.

From audio development and product design to acoustics! Read the Acoustic Solutions Round-Up and expert articles. Check out the NAD M10 Masters Series Streaming Amplifier review, then learn about Sound Liaison, a recording label translating live acoustical recordings in the best possible quality. Jan Didden reflects on "The Internal Life of Vacuum Tubes," and George Ntanavaras introduces his APR-17 Aperiodic Loudspeaker design. audioXpress August 2020, Focus on Acoustics, is now available in print and digital.

Gary Galo reviews the Benchmark HPA4, a reference headphone/line amplifier designed to deliver amplification of analog sources for audio enthusiasts, mixing and mastering engineers. Resulting from Benchmark’s collaboration with THX, the HPA4 features a THX-888 headphone amplifier for an output signal with high voltage, current, and and power complemented by low distortion, noise, and crosstalk. This article was published in audioXpress, November 2019.

This article explains the methods of cutting disc records, the characteristics of magnetic phono cartridges, and how their combined response determines the required playback equalization. The article is based on a paper the author presented at the May 1996 conference of the Association for Recorded Sound Collections (ARSC) in Kansas City, and was first published in the Fall 1996 issue of the ARSC Journal. Later, the article was featured as part of "The LP Is Back!" compilation book published in 1999 by The Audio Amateur company.

The November 2019 edition of audioXpress is now available with a wide range of technical topics in audio electronics and design. We review the Benchmark LA4 Line Amplifier and the new Hooke Verse Bluetooth Binaural Recording Headphones. Jan Didden proposes an updated version of his High-Voltage Delay for Tube Amplifiers, and Thomas Zarbo, Jr. explains how to build his Tenacious Bass-8 Powered Subwoofer. And, learn more about Data-Over-Sound, MU amplification topologies, and Auverdion’s Aurora open-source DSP platform. Now available!

Longtime audioXpress contributor Gary Galo writes about a transformer-coupled balanced output circuit for solid-state preamps, usable with line-level signals. Exploring the differences between balanced interfaces and unbalanced interfaces - and finding things that we really want to be aware of, he then explains why he selected Jensen transformers for his own project. This article was originally published in AudioXpress, February 2019.