It is said that while any competent engineer can design a superb loudspeaker if allowed an unlimited bill of materials, the true test is being able to produce a great-sounding, budget-priced speaker out of parts that cost a mere handful of dollars. With PSB's Alpha series of bookshelf speakers, Canadian engineer Paul Barton has illustrated this truism many times over the years.

Class-D audio amplifiers: What's the argument for them? Class-A audio amplifiers: What's the argument against them? Class-AB amplifiers: Why does everybody make them? Each of these amplifier output architectures has strengths and weaknesses. Each will interface more or less successfully with a given loudspeaker in a given room. Each has a distinctive sonic signature. Consequently, as knowledgeable audiophiles with a laundry list of system-building goals, we are required to choose the amplifier type that best suits our speakers, our room, and our individual musical-aesthetic predilections.

Various Artists: Woodstock: Back To The Garden - 50th Anniversary Experience
Rhino Records A 587817 (10 CD). 2019. Andy Zax, Brian Kehew, reissue prods; Dave Schultz, reissue mastering; Eddie Kramer, Lee Osborne, engs. TT: 12:42:23
Performance *****
Sonics ***

Fifty years, man! By the time you read this, the dates will have passed during which promoters had hoped to stage a 50th anniversary Woodstock Festival—sadly, they failed in their effort—and Woodstock mania will have peaked and died—even pieces of the Woodstock stage are available to buy (I have two!). And yet the artifact that will always remain at the center of the era-defining event is this extensive and amazing audio document that the organizers had the foresight to record.

On Friday, September 27, Apple Corps, Ltd./Capitol/UMe will release, in various analog and digital formats, a remixed and remastered version of the Beatles' Abbey Road, commissioned in honor of that album's 50th anniversary. And on Saturday, September 28, between 3:00pm and 6:00pm—local times—over 40 perfectionist-audio retailers across the US and Canada, coast to coast, will mark the event by playing all 17 of the album's tracks, presumably on the finest imaginable playback systems. (It is a not-unreasonable expectation that at least some of these many playback sessions will take place at the same time, thus stimulating a great harmonic convergence. Or something.)