AES New York 2013
Product Design Session PD7
Sunday, October 20, 2:30 pm — 4:30 pm (Room 1E10)
PD7 - Is Your Equipment Design a Noise Problem Waiting to Happen?Presenter:
Bill Whitlock, Jensen Transformers, Inc. - Chatsworth, CA, USA; Whitlock Consulting - Oxnard, CA, USA
A design goal for all audio equipment is freedom from hum and buzz. But AC power normally creates a system environment of ground voltage differences. While a balanced interface is the first line of defense against this noise source, the balanced interface itself is very poorly understood by most engineers ... and practical aspects of its design are rarely taught in engineering schools. This leads engineers to design balanced input circuits that perform impressively in the lab but exhibit poor noise rejection in real-world systems. To make matters worse, internal equipment grounding schemes are often thoughtlessly designed. Two common results are noise coupled via cable shield connections, known as the "pin 1 problem," and by the AC power cord (so-called "sensitive" equipment). These and other design pitfalls, and how to avoid them, are the focus of this class.