AES San Francisco 2012
Product Design Session PD3

Friday, October 26, 4:00 pm — 6:00 pm (Room 130)


PD3 - Don't Make Your Product a Noise Nightmare

William E. Whitlock, Jensen Transformers, Inc. - Chatsworth, CA, USA; Whitlock Consulting - Oxnard, CA, USA

Audio systems that operate on AC power will experience interference in the form of ground voltage differences, magnetic fields, and electric fields. Although, theoretically, balanced interfaces are immune to such interference, realizing high immunity in real-world, mass-produced equipment is not trivial. Designers who use ordinary balanced input stages fail to recognize the critical importance of very high common-mode impedances, which are the advantage of transformers. Because legacy test methods don’t account for signal sources, most modern audio gear has poor immunity in real-world systems. The new IEC test for CMRR is explained as well as excellent alternatives to ordinary input stages. Other ubiquitous design errors, such as the “pin 1 problem” and the “power-line prima donna” syndrome are described as well as avoidance measures.

Return to Product Design Sessions

EXHIBITION HOURS October 27th 10am – 6pm October 28th 10am – 6pm October 29th 10am – 4pm
REGISTRATION DESK October 25th 3pm – 7pm October 26th 8am – 6pm October 27th 8am – 6pm October 28th 8am – 6pm October 29th 8am – 4pm
TECHNICAL PROGRAM October 26th 9am – 7pm October 27th 9am – 7pm October 28th 9am – 7pm October 29th 9am – 5pm
AES - Audio Engineering Society