Arduino-Based Tube Power Amplifier Controller

In a nod to the Maker Movement, this project uses a common open-source microcontroller module, the Arduino, to build an automatic power controller for a tube power amplifier. The resulting controller is very simple — a $25 Arduino module, a couple of dual op-amps, a few other components, and a 5-VDC power supply plus some opto-isolated switches. This article was originally published in audioXpress, February 2015.

At the 2016 High End show in Munich, and as advertised, visitors could experience the relaunch of the Dynaco ST70 Series 3, stereo tube amplifier, together with the prototype of a new integrated Dynaco ST-1 amplifier. The return of the Hafler and Dynaco brands was signaled in Munich with the return of what is, without question, the most successful tube amplifier of all time. And the new advanced design was sounding great already.

Here is an excellent beginner’s project for those just getting started in this hobby. This “little” amp is easy to construct and has only about 25 parts in each channel. The system transformers are very inexpensive, and the total cost involved for a complete stereo version should be very minimal! This article was originally published in audioXpress, December 2001.

What can you do to ensure the best possible sound from your system? According to Nelson Pass, the “sweet spot” concept is generally regarded as “that happy balance of conditions that elicits the best possible sound,” including the interiors of the components themselves. This article was originally published by audioXpress, January 2010.

Following the intriguing teaser web campaign “Reshaping Excellence”, launched September 1st during an event in London to celebrate its 70th anniversary year, Sennheiser finally revealed the successor to the legendary Orpheus, originally introduced in 1990. The 2015 Orpheus reintroduces the concept of the world’s best headphones.

CE Distribution announced Apex Tube Matching - a new proprietary state-of-the art power tube matching system, designed to ensure the highest-quality matched tubes available. The company performs extensive testing and analysis on each tube that runs through the system to provide accurate and precision-matched tube sets.

When Noguchi, a Japanese audio transformer manufacturer, released its FINEMET core transformer FM-5P for less than $200, the author decided to try it in this four-parallel push-pull amplifier project. This article first appeared in the Japanese magazine Radio Technology, December 2011. It was published by audioXpress in March 2013.

This design by Joseph Norwood Still is a control unit that the author described as offering “lifelike concert-hall performance for a modest cost”. A great tube-based amplifier for phono and line sources, featuring a very subtle bass enhancement control using negative feedback to enhance only selected frequencies, below 400Hz. As the author described, a great project for discriminating audiophiles.

Attention, all first-time (or wanna be) builders of single ended directly heated triode amps. This project’s for you. This is an easy to build, simple direct-coupled input/driver circuit that provides the proper drive voltage to the grid of the 211. A nice way to experiment with a single-ended (SE) triode amplifier.

Here’s a long-forgotten, but still high-quality, power amp design that’s easy to build, requiring no esoteric tubes or parts. Originally published by audioXpress on May, 2003, this project was submitted by Helmut Otte, who worked at the University Of Applied Sciences Hamburg, after having started is electronics career at Philips Service department in Germany.