Book Review: Bob Cordell’s Designing Audio Circuits and Systems

Designing Audio Circuits and Systems is a surprising effort by the author and one that deserves careful exploration. A true compendium of lessons in audio that reflects Bob Cordell’s long-standing track record of designing audio equipment as well as advanced test equipment. The vast content contained in this book makes it an essential reference for anyone designing audio circuits, including excellent “hands-on” material for anyone starting to experiment in audio electronics.

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.

The three previous articles described circuits that Ethan Winer developed for his current project that uses an electric guitar instead of a keyboard to control an analog synthesizer. This article continues with two pieces needed to process input from an electric guitar: the input section’s preamplifier and noise gate, and the pick detector. The preamp amplifies the weak signal from an electric guitar’s pickup and brings it up to line level for further processing. The noise gate detects when a note is currently playing and when it stops. Of course, the pick detector signals each time a new note is picked.

Looking for a headphone amplifier—and a challenge? You can build the design presented in this article with easily obtainable components.

If you're a serious audio electronics DIYer, you likely have a bench-top supply in your workspace. So, how can you determine the stability of your lab or bench-top supply? You can get a good impression of the stability of a power supply under various conditions by loading the output dynamically.

Audiofly added the AF180 to the Audiofly Performance Series of In-Ear Monitors (IEMs). The AF180 offers four expertly tuned balanced armature drivers, and adds crossover circuitry for a sound experience that, according to the company, “redefines the in-ear monitor market”.

The Original Sound Designer. An Interview with Dan Dugan - Audio Engineer, Inventor, and Nature Sounds Recordist. Dan Dugan has spent his entire life involved with audio although, ironically, his first job in the production industry was as a lighting designer. It was when designing the audio for an early 1970s production of the musical Hair that he saw the need for an automated solution to control multiple microphones.

The new Drawmer MC2.1 Monitor Controller combines the complexity of several mix-checking features with the fidelity and transparency of the highest quality monitoring circuit. This versatile and intuitive unit offers multiple inputs and outputs, including a dedicated mono output, speaker-level …

Dr. Amar Bose (1929-2013) Amar Gopal Bose (Amar Gopal Boshu) died recently at his home in Wayland, MA. He was born November 2, 1929, and became the chairman and founder of Bose Corp. (see Photo 1). An American electrical engineer …