audioXpress March 2017, Focus on Test and Measurement, Now Available!

February 13 2017, 09:00
As a long-standing tradition and one of its most popular special focus editions, audioXpress March 2017 includes a wide assortment of Test and Measurement articles, of great interest to both DIY enthusiasts and industry professionals. We would like to greatly thank all the authors for their contributions.
As one of our cover highlights for this special edition, we feature a thorough review by Stuart Yaniger of Audio Precision’s new APx1701 Transducer Interface. This new compact solution, when combined with an APx500-series analyzer, creates a test center suitable for measuring speakers, headphones, and microphones, as well as electronics. As Yaniger finds out, the combination of the APx1701, an APx515, and APx500 software provides an extremely comprehensive and convenient multi-functional measurement test center, of great value and precision.
The next highlight in this month's edition comes from our DIY expert, George Ntanavaras, who submitted his DIM-100 — A Device for Interfacing and Measuring with Sound Cards — for the serious audio hobbyist. The project is so complete and interesting that we have decided to keep the full scope of its description, dividing it into two parts, starting this month with the complete design details. The project is not only fascinating to follow, but we are certain the end result will motivate many of our readers to get to their benches and build one.
Next up, Gary Galo also proposes a useful device, in his case an Audio Dummy Load. As Galo explains, 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, he decided to design a new option for everyone to build now.
Also as part of this Test and Measurement special edition, Chuck Hansen explains how he designed his CAL-69A module tester, after encountering an obstacle at work with his old Tektronix TM501 power module. His tester is designed to detect weak filter capacitors and degraded or failed power transistors. The CAL-69A power module tester includes a power supply selection switch, two reference test points, DMM connection jacks, a test point common, and an LED power indicator.
Finally, Jeff Smith offers a detailed Audio Electronics presentation on how to measure Harmonic Distortion. In his detailed article, the author explains all there is to know about harmonic distortion and describes a few techniques anyone can use to measure it in audio signals. As he writes, "Harmonic distortion consists of frequencies that are integer multiples of an input signal that appear as a result of signal processing. You may or may not want it along with your signal. Either way, it’s educational to see and measure it."
In Sound Control, Richard Honeycutt discusses Community Noise Effects and Measurements. As Richard notes, "The consideration of community noise should be a high priority for all city planners and owners of residential and commercial properties." The article includes an overview of health considerations and regulation implications on Community Noise, as well as Sound Level Guidelines and practical advice on how to measure it.
In Ron Tipton's ongoing series of real-world experiences in audio, this edition includes the third article on Streaming Music Experiences. This month, he focuses on Streaming from TIDAL HiFi. This is TIDAL's Premium option, offering a CD-quality service in lossless FLAC. Want to know how good it actually sounds? Read on.
Of course, as with every edition of audioXpress, Richard Honeycutt writes about the wonderful world of Hollow-State Electronics (tubes/valves for the uninitiated). And in this month's edition, he describes what we all should know before we even consider “Trying Different Output Tubes.”
This edition is now available to access and download online. Just visit:
Of course you can also subscribe here:
And you can also buy a single printed issue or the complete audioXpress issue archive on USB at
related items