So far, as part of my quest to find good affordable box loudspeakers, I have reviewed 16 models, in the August, October, and November 1987 issues of Stereophile (Vol.10 Nos.5, 7, & 8). This fourth group of loudspeakers expands the price range covered, down to $329/pair and up to $1349/pair, and includes one model from California (Nelson-Reed), one from Canada (Paradigm), and one, Monitor Audio's "flagship," the R952MD, from the UK.
Sometimes products are too cheap for their own good, and people don't take them seriously: the Superphon Revelation Basic Dual Mono preamp, Rega RB300 arm, AR ES-1 turntable, Shure V15-V MR cartridge, and the B&K ST-140 power amp. They can't be any good because they cost so little, right?
When I first heard the Eagle 2 at the 1985 Winter CES I knew this amplifier was a winner. I was eager for a chance to get my hands on it, but I also knew that J. Gordon Holt was champing at the bit to do the same. So it came as both a surprise and a delight when ye Gracious Editor gave me first crack at the Eagle 2. I wasn't disappointed; the little Eagle more than lived up to expectations. It's not the best power amplifier I've ever heard, but it's damn good. It is, in fact, better than its big brother, the Eagle 7A, in significant ways; in view of the 2's reasonable price, that's saying a lot.
The Boston Acoustics A40 loudspeaker ($150/pair) has become "legendary" (ie, it's stayed around for a while), probably because a pair of them images as well as Rogers LS3/5As. Unfortunately, it is no match for the LS3/5A in terms of smooth midrange response. Of course, at $150/pair, it shouldn't be.
I was originally going to do a review comparing the Spectrum 108A ($200/pair) and the Boston Acoustics A40. On first listen, I was mightily impressed by the A40. But after Stereophile's Larry Archibald schlepped me out a pair of the 108As, I didn't much want to listen to the A40s.
This is something we don't see too often: an entirely new approach to power amplifier design. As Quad points out in its literature for the 405, class-A operation of transistors provides the lowest distortion, but drastically limits the amount of power an output transistor can deliver without overheating. (Most transistor amps use class-AB output operation, in which each of a pair of power transistors handles part of each signal cycle and shuts down during the other part. Imperfect synchronism between the two halves causes the familiar "crossover distortion," which accounts for most solid-state sound. In class-A operation, each output transistor draws current though the entirety of each signal cycle, eliminating the crossover transition but doubling the amount of time current is drawn, and thus tending to cause the transistor to heat up more.)