Audio Electronics: Testing a Tripath Power Amplifier

Our late and much esteemed author, Ron Tipton, shared a fascinating project on testing Class-T or Tripath power amplifiers on the pages of audioXpress. As he characterized, these "small, inexpensive, and power-efficient units," sounded good "but testing them is problematic." The article also discusses the story of Tripath Technology and speculates on the reasons why the Tripath ICs remained popular among the DIY audio community. This article was originally published in audioXpress, March 2014.

This article by Ron Tipton details the design and construction of the TDL Model 401 high-performance microphone preamp, using a differential input stage that used compound transistor pairs with circuit resistance values, computer optimized for very low output noise. This is a great example of Ron Tipton's TDL Technology projects, which he managed from his home base in Las Cruces, New Mexico. Sadly, the audioXpress community lost one of its most esteemed and prolific writers. There's no better way to pay tribute to Ron than revisit some of these projects. This article was originally published in audioXpress, October 2002.

In this edition, audioXpress pays tribute to one of its most esteemed and prolific writers, Ron Tipton (1936–2018). In our cover feature, Scott Dorsey details his fascinating visit to the Library of Congress National Audio-Visual Conservation Center. Tom Perazella concludes the construction of his flagship Egg Speakers, Andy Lewis explains more about Back EMF, Peter Lehmann shares his time-alignment design for a two-way speaker, and Ethan Winer shares his experience with the affordable LabNation SmartScope USB oscilloscope. And that's just the start of another great edition, now available in print and online.

In this article, Ron Tipton explores the use of stroboscope discs to determine whether your turntable is set to the correct rotational speed. Apart from looking at some commercially available stroboscope discs, Ron Tipton explains how to print one from files that are freely available on the Internet, and explains how to build your own multiple-LED lamp to check the rotations. This article was originally published in audioXpress, December 2010.

This project is based on a previous audioXpress article: “A Solid-State Single-Ended Power Amp” by Ed Simon, published in the April 2006 issue. Ron Tipton was deeply impressed with this amplifier project which used only five transistors per channel, two of them being current sources. This article was originally published in the old audioXpress website as a PDF, but was never reposted. Now we make available online with updated references and links.

I recently purchased a pair of MTX Audio Monitor 5i 5.25″ bookshelf speakers because I needed small monitors for a new computer. I do some audio restoration, so I wanted good sound quality when I wasn’t using headphones. My tests determined that the reviewers were right about the MTX 5i’s weakness in the midrange frequencies. I measured the response and it was not especially flat. This convinced me to update the drivers. This article was originally published in audioXpress, June 2013.

This month, audioXpress features an updated version of the Willow amplifier, especially designed for the DIY community, and a three-way loudspeaker project with an external active crossover network. We visited Eighteen Sound in Italy, discuss experiments with Dolby Atmos, audio networking development based on Audinate’s Dante technology and learn how to measure Reverberation Time (RT). And if you are interested in recreations of the famous Fairchild compressor/limiters, rectifier tubes, and how to properly test tubes, don’t miss this month’s audioXpress.

Ron Tipton explains how he built his sound level meter and spectrum analyzer, the Model 527, around a Velleman Audio Analyzer kit (K8098). This is a barebones kit with no enclosure or power supply, but for the price, it is very versatile. Originally published in audioxpress, December 2013.

Usually we think of noise as a signal to be eliminated, or at least reduced, in any audio system. However, noise can be a very useful test signal because it is inherently broadband, which is faster and perhaps more accurate than spot or swept frequency testing. Article originally published by Voice Coil, December 2010

You can inexpensively calibrate a microphone. How? In this article audioXpress author Ron Tipton discusses two methods of “secondary” calibration: the electrostatic actuator and microphone comparison.