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.

Or why not all grounds are created equal. How to mitigate grounding issues in audio equipment, understanding resistance, inductance, and capacitance of ground wiring, and voltage differences between points. Also, how not add to the construction complexity.

Series voltage regulators are a great way to provide almost-noise free and rock-stable DC to your audio circuits. But the load current often has distorted signal components that can generate a ‘dirty ground’ across the supply ground wires and tracks. This can introduce distortion components in other circuit sections using this ground. With shunt regulators we can keep the dirty ground localized and largely avoid the problem. Technical Editor Jan Didden explains.

German audio interface specialists RME Audio, announced two new solutions designed to improve the performance of its ADI-2 series of converters in critical applications. The RME DPS-2 is a super low noise linear audio power supply with a unique µfilter and sensor technology that adds a wide range of unique and highly useful features such as offering two differently filtered outputs. The second product is the LNI-2 DC, an active DC filter with galvanic isolation.

A great first 2018 issue of audioXpress is now available to download! audioXpress January 2018 reviews the surprising Vanatoo Transparent Zero powered, wireless, and inexpensive speakers. We report on what sounded good at the Rocky Mountain Audio Fest (RMAF) 2017 show, and Robert Nance Dee returns with the 6922 tube hybrid amplifier, a complete design in his series on buffered preamps... and much more!

Switched mode circuits are increasingly being used today in electronic devices. Due to the rapid switching speeds found in these switched mode circuits, the probability of high frequency ground connection interferences is also becoming more prevalent. A correctly specified and placed ground choke, using Schurter’s range of power IEC modules with line filter and optional voltage selector (step switch), offers a simple and safe solution.

Inspired by a presentation by Bill Whitlock, President of Jensen Transformers - a three-hour tutorial seminar titled “Audio System Grounding and Shielding: An Overview” - during the Audio Engineering Society convention in New York in 2007, Gary Galo decided to investigate a little more into the subject and do some reviews of the mentioned equipment.