Spectron Musician III Amplifier:
Why Digital?
       

The Goal

 The dream of building a digital amplifier for audio applications has occupied the mind of many an engineer. Although digital amplifiers have been used in other applications, a practical design for an audio-specific amplifier posed a much more difficult challenge.

 On paper, digital switching amplifiers have many practical and theoretical advantages over the traditional AB amplifier designs. They can be smaller in size, much lighter weight, produce far less heat and use significantly less energy than a traditional amplifier of equal power. A digital amplifier, at roughly 90% efficiency, draws far less current than an AB amplifier, most of which operate at 30 – 35% efficiency. Theoretical advantages in the areas of circuit speed, distortion, feedback and output impedance are beyond the scope of this brief commentary, but I invite you to read more on the topic at the Spectron Website here.

A Long Road

 Likely no one has spent as much time on attaining this goal as John Ulrick, founder of Spectron. Since the early 1970’s John has been experimenting with and refining the techniques required to build an all-digital power amplifier for audio. A bit of background is in order.

 In 1968 John Ulrick co-founded Infinity Systems (the speaker company) with Arnie Nudell. Together, Nudell (a physicist) and Ulrick (an electrical engineer), soon built a name for themselves with their speakers.

 Shortly after Infinity’s inception, John began working on a digital amplifier for audio applications. A great deal of research and development went into the project, finally culminating in the release of the World’s first digital switching amplifier. Infinity sold several hundred of these early designs, a 125 watt unit known as the SWAMP 1.

 In 1979 John sold his interest in Infinity Systems to pursue other avenues. Though on the back burner (while other pursuits paid the bills), John continued his commitment to further refine digital amplification. Eventually, Spectron was born.

 The Product

 The latest offering from Spectron, the Musician III, embodies all the knowledge and experience John has gained over years; and it shows. The Musician II is an outstanding amplifier. Most things it does as well any other amplifier out there, some things it does better than any amplifier.

 The Musician III's exceptional performance is due to a number of factors including its 10x over sampling of the analog signal, extremely fast feedback loop (10x times faster than conventional amps), the substantial headroom offered by 600 watts per channel combined with extremely low perceptible noise and distortion. While it's increasingly harder to make an extremely good amp better, each of these new technologies can make a discernable difference.

The Sound

 The term “digital” has a bit of a negative connotation within the audiophile community; it often being associated with a cold, hard or grainy quality. So, don’t these negative characteristics affect the sound of a digital amplifier? Not if it is a Spectron.

 Another noticeable difference is the smaller size and lighter weight of Spectron amps. Cooling needs are minimal because of the amplifier's 90% efficiency. As a result cooling is strictly by convective air flow. The Musician draws only 67 watts when there is no input, whereas conventional amps can draw up to 70% of their rated power with no music playing.

 Though it’s a powerful amplifier, it doesn’t beat you over the head with that fact. Some high power amplifiers are indeed muscular, but lack finesse. The Spectron uses it’s power to control the speaker and convey large scale dynamics, when the music calls for it, but it also can be delicate and graceful.

 In Positive Feedback, Mike Pappas, Associate Editor, Digital Technology writes: “The Spectron 1KW amplifier redefines the state of the art in power amplifier designs. It does everything right, so right that words cannot totally convey what this amplifier is capable of doing. (Yeah, I'm considering setting fire to the old word processor!) And that isn't the half of it. I've saved the best for last. If this amp cost an arm and a leg, or you had to auction your significant other to even daydream about it, that would be one thing. You could read this review; shrug your shoulders, and say, "Hell! Another damned amp I can't possibly afford" BUT - and hang on to your shorts, Mort - at an MSRP of just $3,495, the Spectron 1KW is a bona fide killer!! Competitors are hereby served notice that the Spectron 1KW is a bone-bustin' foe requiring a wide berth...”

 Bascom King reviewed the Spectron for Audio: “…Specifically, I would characterize the sound of the 1KW as having an easy, slightly laid-back sound. Its bass was powerful, tight and “tuneful,” and its upper mids and highs were spacious and open. Depth and soundstaging were very good…”

 Click here for more about the Spectron amplifier.