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.

Since 2017, D.W. Fearn, the manufacturer of professional vacuum tube audio recording equipment, handed over the production and marketing of its iconic line of gear with the distinctive red front panels to Hazelrigg Industries under an exclusive licensing agreement. Now, D.W. Fearn | Hazelrigg Industries, have announced the opening of their first Canadian offices, headed up by tech industry veteran Scott Taylor.

Celebrating the reintroduction of the famous Western Electric 300B triode, now out of Rossville, GA, in this article, Richard Honeycutt asked key questions to entrepreneur Charles Whitener, the main force behind the revived Western Electric venture, which is also investing in new tube audio amplifiers and tube related electronics. Since a visit to the facilities wasn't yet possible but production had resumed, audioXpress provided an inside look at Western Electric and its reestablished operations. This article was originally published in audioXpress, May 2021.

Our May 2021 Glass Audio Special edition is certain to inform and inspire you. We reveal what is happening at Western Electric's new Rossville Works in Georgia, where production of 300B tubes is ongoing, we explain how to draw tube load lines, and we offer a valuable preamplifier design that enables you to compare the sound of tube and solid-state circuits from the same audio source. There's also a versatile stereo tube amplifier design to build, and plenty more audio electronics theory and practice in this edition. Now available online and in print.

In this article, Menno van der Veen explains everything about the Vanderveen Trans-SE10 amplifier, which is available as a DIY kit manufactured by Tentlabs. This letter-sized stereo amplifier is a single-ended design with an output power of 10W per channel, but there's a lot "under the hood" (and the glass) to understand. The article explains the “why and how” of the unusual Vanderveen Trans-SE10 design. This article was originally published in audioXpress, January 2021.

A few years ago, Jan Didden designed a high-voltage delay unit and shared its details in a 2019 audioXpress article. Many people built it and like it, but others said that it would be totally unnecessary. As so often happens in audio, arguments pro and con raged without a clear resolution. So Didden thought this was something he needed to get his head around. He found several sources, which he thought were credible, and this article is the result of his investigations, fed by those sources. This article was originally published in audioXpress, August 2020.

The Bavaria-based headphone manufacturer just introduced a new high end product to complement its existing high-end Edition Series headphones. Designed by Ultrasone and manufactured in Hungary, the new Volcano headphone amplifier continues the brand's tradition of aiming for reference products with superior sound quality, also perfectly matched to the Ultrasone Edition 15 reference headphones. Each Volcano is a carefully handcrafted unit, in a solid metal chassis and front panel with real wood side panels.

I ordered this book, Getting the Most Out of Vaccum Tubes, from KCK Media Corp. while I was researching tube service life issues. It is an unusual book, not discussing what you can do with tubes, how to use them in circuits, operating parameter calculations, or that sort of thing. Instead, it is solely devoted to factors that decrease useful service life or cause catastrophic failures.

High-end audio adepts do not only like music. Many of them also like to construct their own tube amplifier. For those, Menno van der Veen (electronic design) and Guido Tent (mechanical design and realization) created their newest Valve Amplifier kit: the Vanderveen-Trans-SE10. All parts of the case, the components and the transformers are of the highest quality. The DIYer only has to combine all these fine components into a great amplifier.

We invite our readers to a return to the past, when the original Blackburn manufacturing site where Millard tubes were once made, was shipping the TechTube Blackburn E813CC - an engineering effort to redesign the ECC83 dual triode, claiming more accuracy and more consistency. "The famous Blackburn MicroTech Solutions tube factory has launched the first in a line of audio tubes featuring the first radical re-design in tube technology in over 40 years," writes Neville Roberts in his original 2009 report for audioXpress.