You Can DIY! eDD - A Direct-Drive Amplifier for Electrostatic Speakers

This article details a lifetime project from audioXpress' technical editor Jan Didden. After a successful restoration project of a pair of precious ESL-63 Quad electrostatic speakers, he opted to design and build the eDD, a well-performing high voltage amplifier to directly drive electrostatic speakers. This challenging but successful DIY project with a design goal of 1500V RMS at 20mA RMS over the full audio band, took a while to complete but was a success. This article shares every step of the construction.

This article reviews an intriguing new patent awarded to Turtle Beach Corp. addressing a new emitter circuit for providing a bias voltage, which is key for the development of electrostatic loudspeakers. Extremely aware of the techniques and historical perspective of the development in this area, Croft provides a complete overview of all the challenges, implications and merits of this patent and prior art. This article was originally published in Voice Coil, July 2018.

In this very strong edition of Voice Coil, focused on up-to-date topics for loudspeaker professionals, we discuss the industry's Asian supply chain, how a new carbon composite dome compares with Beryllium and Titanium products, and James Croft reviews a recent electrostatic loudspeaker (ESL) patent. Vance Dickason focuses his attention on two innovations coming from Eminence, in two extreme product categories. The new Eminence NSW4018-8 18" Tour Grade Woofer, and the new N314X 1.4" compression driver, which is the first to use TeXtreme composite material for the diaphragm. Download your copy now!

Our Speaker Focus edition offers a review of the two new SB Acoustics Speaker Kits, while Don Keele, Jr., reminds us of how things evolved, revisiting an EV 30W subwoofer project, and we interviewed Zoltán Bay, creator of the revolutionary Bay Radial Speaker! The September 2017 edition also features two great DIY projects: The Thinman Speaker by Ken Bird and a Hybrid Electrostatic Speaker with Tailored Dispersion by Charlie Mimbs.