Power amplifiers fascinate me. In the past 15 years I've helped design and build over a dozen advanced models, with output powers ranging from 50 to 2500W, for a number of the UK's professional equipment manufacturers. To learn from others' ideas and mistakes, I've also repaired, measured, used, and reviewed hundreds of makes of amplifier. My experiences have led me to regard the power amplifier as one of the messiest, most imperfect pieces of electronic equipment in the record/replay path.

Armando Anthony "Chick" Corea belongs to that elite cadre of pianists that includes Herbie Hancock, Keith Jarrett, and Mccoy Tyner, pioneers who reshaped the jazz or- der starting in the early 1960s and continued to make strides into the present day.

The now-78-year-old Corea's attainments are many: composer of the standards "la fiesta," "Spain," "500 Miles High," "Matrix," and "Windows"; winner of 22 Grammy Awards (and 64 nods); founder of at least six colossal improvising units (Return to Forever I and II, Circle, the Three Quartets quartet, the Chick Corea Elektric Band, the Vigil Quintet); popularizer of early monophonic synthesizers, and recipient, in 2006, of an NEA Jazz Masters award.

99% True: Almost a National Bestseller, by Paul McGowan. Lioncrest Publishing, 2019. 364pp. $25.00, hard cover; $15.99, paperback; $9.99, Kindle e-book.

To many audiophiles, high-end audio manufacturers must seem like monolithic entities, enduring for what seems like forever, like cliffs beside a familiar path. But as Paul McGowan explains in this unputdownable autobiography (footnote 1), behind the facade of stability things can be in financial turmoil, with success equally as risky as failure.

In a late-August newsletter, PS Audio announced a major change in how it does business. In the United States, its home market, the company stopped selling its products through dealers and opted for a direct, online-only sales model. Outside the US, it will continue to sell through authorized dealers.

Audio Vision SF, one of San Francisco’s two major high-end dealerships, celebrated its 20th anniversary on September 27–29 with a three-day celebration in two locations.