You Can DIY! Use Brüel & Kjær Instrumentation Microphones for Recording

In this article, Scott Dorsey shares his unique experience-based tips for converting a classic Brüel & Kjær measurement microphone system into a valuable recording microphone. Vintage instrumentation Bruel's (the ancestors of the DPA's) are great microphones that can be found on the surplus market and are appropriate to use for recording applications, if you know which ones and how to convert them. This article was originally published in audioXpress, July 2016.

"Before you start measuring and playing around with your new speakers, maybe you should know your room." The statement, inspired Ethan Winer to write this article from a very practical perspective, helping us to understand the acoustics of our own listening rooms, and how measurements will help us. The examples contained in the article use the popular Room EQ Wizard (REW) software. This article was originally published in audioXpress, August 2021.

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 project article for audioXpress, the author shares his guitar tube amplifier, a simple, low-wattage, that any DIYer can easily build. Costas Sarris believes in building simple tube amplifier designs, with simple circuits that he found to work better, particularly when the electric signals carry music information, because the signal distortion is easily handled. This article was originally published in audioXpress, June 2015.

This modification and restoration article shows how to preserve the best features of unused tube equipment. The article describes a tube preamplifier that the author wanted to position at the input to his home power amplifier, eliminating the need to adjust his 1972 McIntosh MX10 tuner and 240 power amplifier’s volume high when he wants to fill his home with music. In this case, an old Shure Model 65 stereo conversion preamplifier using two dual-triode 12AX7 tubes provided an excellent platform for the project. This article was originally published in audioXpress, May 2020.

This article from Dimitri Danyuk explores ways to provide better isolation between input and output terminals and lower input noise current using JFETs from Linear Integrated Systems. For unity-gain buffer applications there are many open-loop IC buffers on the market based on bipolar technology. They are mostly complementary emitter followers connected in series. With the appearance of complementary JFETs from Linear Integrated Systems, it is possible to construct a discrete buffer with JFET input. This article was originally published in audioXpress, March 2019.

For our readers who like to get hands-on with DIY projects, in this article George Ntanavaras describes the design and the construction of his PR-3 stereo analog preamplifier, offering three high-level unbalanced stereo inputs and two unbalanced stereo outputs. Most of the components for this design are contained on a single PCB. This article was originally published in audioXpress, January 2019.

For all our readers who started following the X-Altra Moving Coil/Moving Magnet RIAA EQ Preamplifier DIY project publish in the February 2021 edition of audioXpress, we have the final pieces. In this second article, Andrew C. Russell details the Moving Magnet EQ stage, system gain amplifier and filters, along with the system’s power supply unit. The article concludes with some measurements.

In this DIY project, Andrew C. Russell proposes the X-Altra, a highly refined Moving Coil/Moving Magnet RIAA EQ Preamplifier. This high-performance phono equalizer features an ultra-low noise LSK389B JFET from Linear Systems in the MM front end with switchable gain and resistive loading. This article was originally published in audioXpress, February 2021.

In this article, Jack Elliano the founder and principal designer behind Electra-Print Audio, details a simple but very interesting concept of a line amplifier using step-up transformers plus a variable gain control, offering usable results from low impedance sources. The preamplifier project uses Electra-Print handcrafted transformers, which the company manufactures for its own high-fidelity tube audio components, directly from its home base in Las Vegas, NV. This article was originally published in audioXpress, January 2005.