AES PNW Section Meeting Report
October 11, 1996
Maximum Audio Mileage from Amplifier I.C.s, with Walt Jung of Analog
Devices
3 images from the meeting. (64K color
GIF with 3 images) Top: Rick Chinn; middle: Group and Walt;
bottom: Walt Jung. Rick Smargiassi photos.
About 32 people came to Jack Straw Productions Studios in Seattle on
October 11, 1996, to hear Walt Jung speak on audio amplifier I.C.s.
PNW chair Dan Mortensen opened the meeting with some Section business. He
announced the tentative upcoming schedule of AES meetings: November, Audio
Control Iasys; December, Rane tour; January, St. James Cathedral's sound
system with Peavey Media Matrix; February, Mackie tour.
Dan made a procedural motion to amend our bylaws to allow more committe
members, a practical matter that has never prevented us from having more
than the stated "3 committee members." The wording should be changed to
say there should be "at least 3 committee members." 15 members must be
present for
a vote. Dan counted 15 members. A voice vote was in favor. Rick Smargiassi
seconded the motion.
Dan asked everyone in the room to introduce themselves, and Rick Chinn
introduced Walt Jung. Walt is well known as a guru of audio op-amp
design. His books, such as Audio I.C. Op-Amp Applications, and
I.C. Op-Amp Cookbook, perhaps inspired a whole generation of
professional audio designers. Now an applications engineer for Analog
Devices, Walt continues the dissemination of ways to use op-amps for high
quality audio.
Armloads of literature and article reprints were passed out. The majority
of the evening was spent reviewing material from the Analog Devices System
Applications Guide book, section 8 (audio devices). When offered as a
course, it takes 2 days, so some material was skipped. Many mic preamp
circuits were discussed, some designed with help from Jensen Transformers.
Many
tweaky questions were fielded by the audience, including what kind of
resistors to use in certain places, and what kinds of capacitors. The
section on RIAA circuits was skipped. Line drivers were examined. Better
voltage regulators were discussed. The concept of thermal distortion was
brought up.
Afterwards, Walt indicated that he was very stimulated by the quality of
the interaction, and wished to return in the near future for another
meeting.
report by Gary Louie