Solid State Power Amp Reviews

To high-end audiophiles, the Boulder 500 amplifier and its less expensive derivative, the 500AE (Audiophile Edition), would not seem to be "high-end" designs. They are designed around op-amps (felt by many to be generally poor-sounding), they have scads of negative feedback (which is perhaps why op-amps sound bad), and they have only a moderately hefty power supply. Why, then, is Stereophile publishing a review of an op-amp–based power amplifier? Read on...

Boulder Amplifiers, named after the Colorado town where the company has resided since its founding 23 years ago, makes some of the most elegant-looking solid-state amps around. Chassis are anodized, aircraft-grade aluminum with rounded edges, machined and finished in-house. The two models reviewed here, the 810 line preamplifier and the 860 power amplifier, each have a sleek, compact build—stacked atop each other, the two stand just over a foot high—owing to extremely efficient packing of the circuitry inside. These are the company's "entry-level" electronics, but there's nothing cheap about them—the preamp retails for $6900, the amp for $8500—and for all their economical size, they look like luxury goods as well.

How much amplifier power do you need? Most audiophiles figure a maximum of a few hundred watts per channel—beyond that, you're wasting your money or showing off. Others think that anything more than a few watts will mess up an amplifier's musical coherence or "purity," so they stop there and find uncommonly sensitive speakers, usually compression horns with cone woofers.