Mr. Whitlock is among a handful of internationally known experts on grounding and shielding. He has designed pro audio and video electronics for 30 years. In 1989, after seven years with Capitol Records, he became president of Jensen Transformers. His paper on balanced interfaces, which appeared in the June 1995 JAES, has become the most popular ever printed there. Other writing includes the "Clean Signals" column in S&VC magazine, three chapters for Glen Ballou's "Handbook for Sound Engineers," as well as numerous application notes and magazine articles. Bill holds several patents including the InGenius® balanced input circuit and a high-speed feed-forward ac voltage regulator. He is also an active member of the AES and the Institute of Electrical and Electronic Engineers (IEEE).

As if the term "ground" weren't confusing enough by itself, many practices and beliefs surrounding signal interfacing in audio, video, and data systems are rooted more in myth than in science - many of them are reinforced in respectable textbooks. The presentation examined, and hopefully dispelled, some common myths on these ten subjects. We will not attempt to reiterate the information presented, but here are the Whitlock Top Ten:

1. Earth grounding — is the safety of the 3rd prong due to earth grounding?
2. Zero-impedance wire — is there such a thing?
3. Shielding unbalanced cables — how effective at reducing noise pickup?
4. Which end of a balanced cable shield to ground?
5. Signal symmetry versus "balance" — what rejects noise?
6. Single op-amp balanced input "dilemma" — is it really balanced?
7. Audio cables as "transmission lines" — do they require termination?
8. Impedance matching — do load and source need to match?
9. Equipment itself causing noise problems — how common?
10. Vulnerability of digital interfaces — are they immune to these noise problems?

Our special thanks to Mr. Whitlock, who donated his efforts to specifically benefit the AES, and to Mackie Designs, who donated their facility.