Reducing Filamentary Triode Amp Distortion

In this article, the author defends that it’s possible to dramatically reduce the intermodulation distortion in class A filamentary triode tubes by reducing the filament voltage. The theory being that the most important reason for the drop in distortion with the lowering of filament voltage is the reduction of the space charge. This article was originally published in audioXpress, May 2005.

In this article for audioxpress, Ed Simon writes: "There seems to be controversy over what testing means in audio. Measuring a difference does not mean you can hear it. On the other hand, if my ears tell me there is a difference between two audio chains and I cannot measure it, that does not mean it is not there. Probably, I'm just using the wrong method to determine audio differences." And after trying to measure all sorts of things to compare which ones sounded fine - or not - he decided the next step would be to build a dedicated more sensitive measurement. This article was originally published in audioXpress, November 2009.

Anyone who is serious about designing a loudspeaker using dynamic drivers is either familiar with, or has used, Thiele/Small parameters, generally accepted as ways to predict driver behavior in different enclosures. But there are other measurement methods we can use to determine and quantify nonlinearities: the DUMAX system, produced by DLC Design, and the Klippel Analyzer System by Klippel GmbH. This article was originally published in audioXpress, March 2003.

HEAD acoustics, one of the world's leading companies in the field of voice and audio quality optimization, introduced HQS-Audio, a new tool for its ACQUA analysis system that provides whole set of targeted electroacoustic measurements and helps to comprehensively test the quality of audio devices. Whether loudspeakers, headphones, or audio systems in vehicles, HQS-Audio provides independent test runs for each application, consisting of various electroacoustic measurements, including Thiele-Small parameters.

audioXpress readers are well familiarized with Richard Honeycutt's Hollow State column. In many of his articles, Honeycutt explored distortion in a quest to find the origin of “tube sound.” In this article, he takes a more general view of possible amplifier differences, solid- or hollow-state, focusing on different amplifiers’s differences in sounds, and a correct subjective evaluation process of components and systems. This article was originally published in audioXpress, October 2012.