Ben Duncan

Spectral X-Contamination: Problems in Op-Amp Chips
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Ben Duncan  |  Sep 09, 2020  |  First Published: Jun 01, 2001  |  30 comments
In high-end circles, the sonic repute of integrated-circuit op-amps (from "operational amplifier") is, at best, checkered. Of course, the expertise with which they are used and the parts they're used with can make all the difference. For example, my DIY preamplifier design, "AMP-02," published in Hi-Fi News & Record Review in 1989–90, and my earlier (1983–84) AMP-01 (footnote 1), I used the better IC op-amps of the time throughout. Both units were thought to outperform cost-no-object commercial units of the time that employed discrete transistors and even tubes, and only indicate what's possible.
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What a Difference a Wire Makes
Cable ReviewsHistoricalReference
Ben Duncan  |  Jun 12, 2020  |  First Published: Dec 01, 1995  |  71 comments
Testing the RF transmission of Kimber Kable, up to 3GHz, at Ben Duncan Research Labs, in 2008. The resulting proof of RF rejection was published on-line by Russ Andrews Accessories in England. (Photo: Naomi Swain).

Editor's Preface: In an article in the October 1995 issue of Stereophile, Professor Malcolm Omar Hawksford used Maxwell's Equations to develop a mathematical model describing the behavior of cables at audio frequencies. Among the predictions of this model were that for good conductors there exists an optimum size of wire for audio signal transmission, and that for a wire larger than this size an energy storage mechanism would exist. In his article Malcolm described a simple experiment, the results of which appeared to confirm his hypothesis.

Then serendipity struck. English engineer Ben Duncan, whose writings have occasionally appeared in Stereophile, sent me an article he had written for the pro-audio magazine Studio Sound. The results of a series of cable measurements he had performed seemed to confirm the Hawksford Hypothesis. We offer them here for your delight and delectation.—John Atkinson

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The Uncertainty Principle
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Ben Duncan  |  Feb 12, 2020  |  First Published: Jul 01, 1995  |  7 comments
Have you ever suspected that the component you bought after diligent research is somehow not "typical"? That its sound seems to bear little resemblance to the descriptions in the reviews you read? Sure, you listened to the unit before purchase, but the one you took out of the box at home—was that the same unit? And if you suspect your new unit's sonic quality is below par, just how do you or your dealer go about proving it?
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Harmonic Convergence: the Effect of Component Tweaking
FeaturesReference
Ben Duncan  |  Oct 10, 2019  |  First Published: Jan 01, 1992  |  10 comments
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.
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