A Versatile Line Amp for Preamp, Headphone, and Power Use

Here’s a do-it-yourselfer’s dream in tube amp design: four operating modes, high quality, low cost, and low distortion. An article originally published by audioXpress in May 2007. A true versatile project which we think deserves to be shared.

Erno Borbely is not a man given to bragging about his accomplishments. But from the venerable Hafler DH200 to today’s high-performance all-FET amplifiers from Borbely Audio, he has left his mark on 40 years of technological audio advancement. Jan Didden looked him up in his home close to Munich, Germany, and talked with him about audio and other tidbits.

The December 2014 edition of audioXpress featured a review of the Universal Audio Apollo Twin Thunderbolt-based audio interface. Oliver Masciarotte details how Universal Audio approached this design, leveraging the benefits of Thunderbolt technology and its own hardware-accelerated UAD Powered Plug-In architecture to implement a complete recording solution. Read the Complete Review.

This project, originally published by audioXpress in December 2011, has been the topic of much discussion, updates and follow-up projects, so much so that we decided to make it available online. As the author, Robert Nance Dee, explains, “…the people who have listened to this amp can hear the difference. I built it as a companion to my 5002 power amp, both using the HA5002 buffer.”

An excellent article from the audioXpress archive, published originally in February 2003, James Moriyasu offers a complete study examining speaker cabinet edge diffraction and what we can do to reduce it. The author attempts to measure the extent of acoustic edge diffraction and test possible solutions for reducing its levels

With a little know-how and some basic parts, you can design a hybrid amplifier in fairly short order. This project combines the best attributes of both tube and transistor technologies.