The presenters were:

James (JJ) Johnston of Microsoft. Mr. Johnston worked 26 years for AT&T Bell Labs and its successor AT&T Research Labs. He was one of the first investigators in the field of perceptual audio coding, one of the inventors and standardizers of MPEG 1/2 Audio Layer 3 and MPEG-2 AAC. Most recently, he has been working in the area of auditory perception of soundfields, ways to capture soundfield cues and represent them, and ways to expand the limited sense of realism available in standard audio playback for both captured and synthetic performances. He is an IEEE Fellow, an AES Fellow, a NJ Inventor of the Year, an AT&T Technical Medalist and Standards Awardee, and a co-recipient of the IEEE Donald Fink Paper Award.

Dr. Melissa Harrison, Ph.D., of Full Moon Technical Solutions LLC. Dr. Harrison is an independent technical consultant. She has a PhD in applied mathematics from the University of Maryland and is interested in signal processing, particulary for audio signals. She has worked in various areas of computing and mathematics for over 20 years, including Fourier analysis, irregular sampling of bandlimited signals, robotic vision & route planning, optical holography, switched-circuit network provisioning, mathematical and scientific programming, system administration, and technical typesetting. She has over 10 years experience teaching mathematics at the university level.

Steven Green of Cirrus Logic. Mr. Green has over 25 years experience in the audio business including nearly 13 years with Crystal Semiconductor / Cirrus Logic as an Applications/Technical Marketing Engineer. In this role Steve has had the privilege of working with many of the leading mixed-signal IC and audio hardware design engineers from around the world. Steve has also authored several papers for the AES, multiple Crystal Applications Notes, magazine articles and is a co-author of the 1995/1996 Crystal Semiconductor "World Tour" Applications Seminar. Prior to Crystal/Cirrus, Steve worked as a design engineer for White Instruments.

Dr. Richard Cabot of XFRM, Inc. Dr. Cabot has 4 degrees, including a Ph.D. from Rensselaer Polytechnic Institute and an MBA from Pepperdine University. After 6 years in engineering at Tektronix, he was a co-founder and the CTO of Audio Precision. He designed the System One analog generator and the digital sections of all the products until selling the company in 2000. His current firm, XFRM, Inc. (pronounced "transform ink") does research and consulting in digital audio technology. They can be found on the web at www.xfrm.com. He has held several positions in the AES, including President, and has presented numerous papers on audio technology both to AES conventions and conferences as well as to other organizations.

Providing electronic demonstrations were Bob Moses of Island Digital Media Group, LLC and current AES Western Region Vice President, and Steve Macatee of Rane Corp.

Bob Moses spent 8 years designing digital products at Rane before leaving to co-found PAVO and Digital Harmony in 1995. He subsequently went to work as a consultant, working for a variety of pro and consumer AV companies including: JBL, Microsoft, Audio Precision, Intel, Alesis, BridgeCo, AKM, Dolby, Harman Consumer Group, Meridian, M-Audio, and others. Bob is also serving a second term as AES Vice President of the Western USA/Canada region, and is the chairman of tutorial sessions for the upcoming 117th AES Convention next fall. He won the Life Member Award from the IEEE about 20 years ago for work he did on Oversampling for CD Players.

Steve Macatee has worked at Rane Corporation since 1987 in several capacities: from manufacturing; mechanical, interface & PCB design; in-house & product documentation; analog, digital and embedded systems After a decade in R&D Engineering, Steve underwent an Inverse Dilbert Transform and moved to Sales for 4 years as a technical and consultant/contractor liaison. He currently heads the New Product Development and Training department at Rane where he works to define new product & technology ideas.

PNW Treasurer Dan Mortensen moderated the program.

JJ Johnston began the seminar with a presentation on human hearing. "What can we hear?" he asked. He covered the elements of the human hearing mechanism, including the structure of the ear and hearing limits, the pinna and HRTF (head related transfer function), the middle and inner ear.

A short break was held, then Dr. Melissa Harrison presented "Fourier Analysis and the Basics of Analog to Digital Conversion." As implied, this covered the basic principles of the entire PCM analog to digital conversion process, and the elements of math behind each step in the process. She showed the process from analog input, to anti-aliasing filter, to sampling, quantizing and encoding, then to decoding, zero-order hold and low-pass recontruction filtering to the analog output. To do this, topics included Fourier analysis, Discrete and Continuous Convolution, Sampling and the Time-Frequency Duality, Reconstruction and the Time-Frequency Duality, Aliasing, Quantization Error and Oversampling, Jitter, Noise Shaping, Dithering and Decimation.

After the no-host lunch break, Steven Green of Cirrus Logic began his presentation of analog to digital converters from a manufacturer's viewpoint. The well-known problems of converters were explored, such as dynamic range, time delays, and the audibility of decimation and interpolation filters. A lively discussion with the audience was held, including topics such as high sample rates.

Among several demonstrations during the day, Bob Moses and Steve Macatee provided a demonstration of jitter versus distortion. The amount of jitter was varied and a speaker played the result.

After the afternoon break, our prize drawing was held, with the following winners:

• Jim Angerer won the book, "Mastering Audio" by and from Bob Katz.
• Gary Fryer and Jacob Morris won AES Perceptual Coding CDs, provided by the AES.
• Somsak Sukittanon, Andrew Kane, Brian Willoughby won Genelec wavelength tape measures, provided by Dan Casado/First Choice Marketing.
• Stephen DeVore, Rick Fisher, Ron Hyder won NAMM show guidebooks, provided by Dan Casado/First Choice Marketing.
• Drew Cady, Melissa Harrison, Austin Sousa won AES Convention Exhibitor directories, provided by Rick Chinn.
• Evan Davis won a one year online AES membership, provided by the AES.

Finally, Dr. Richard Cabot talked about the systems aspects of A to D converters, with a review of the PCM and Delta-Sigma/Sigma-Delta modulation designs and their problems such as jitter and idle tones. He made interesting comments on the supposed superiority of SACD releases - believing them to be more an example of carefully mastered music, rather than an inherently better digital system. He noted that one cannot perform audio processing to a 1-bit SACD stream, and it must be converted to PCM (or their term, DSD-Wide) 8-bit, 384 kHz for processing.

This concluded a very long day packed with converter information.