An Interesting Way of Looking at Evaluating Equipment Quality

Caelin Gabriel, founder of Shunyata Research, visited my listening room yesterday to hear his new CX Series power cords in my system. Shunyata makes the state-of-the-art in AC power conditioning and AC power cords, at least in my experience. Their HYDRA V-RAY power conditioner and PYTHON AC cord won our Product of the Year Award in 2008, and their other products have been honored with various Golden Ear and Editors’ Choice Awards. I’ve been using Shunyata products in my reference system for the past two years.

During the course of a discussion on the role of AC power in an audio system, Gabriel made an interesting analogy about judging the effects of power cords in a system. It goes like this: Dump five spoonfuls of dirt into a glass of clean water and stir. Look at the resulting dirty water. Repeat the exercise with four spoons of dirt. Can you discern the difference in contamination one additional spoonful made? Probably not. Now dump one spoonful of dirt in a glass of clean water and the same amount of contamination (one spoonful) is instantly obvious.

Gabriel says evaluating the effect of a single AC power cord in a non-optimized system is like trying to determine whether the glass of water has four or five spoonfuls of dirt in it. The improvement one cord makes is largely swamped by the poor performance of the rest of the AC-delivery components. Gabriel advocates evaluating an AC power-conditioner and AC cords as a system, judging the system’s effectiveness against stock cords or against other products. Simply put, one can judge the effect of a single AC cord only after the audio system’s AC power has been optimized.

I’ve long subscribed to this view that an audio system must be transparent in order to judge the quality of a single component, but Gabriel’s analogy makes the point vividly clear. I had not, however, considered the implications of assessing a single AC cord within the context of the rest of the power-delivery system, although I’ve reviewed AC conditioners/power cords by removing the entire system and putting it back in for the listening comparisons. Incidentally, during Gabriel’s visit I was reminded of the first time I heard a difference in power cords. It was 1990 and I was reviewing two similarly priced power amplifiers. After about two weeks of listening, the designer of one of the amplifiers visited me to hear his product. While comparing the two amplifiers he had a puzzled look on his face. He went behind the amplifiers and saw that I had accidentally switched the stock AC power cords that were supplied with the amplifiers. When I unpacked and set-up the amps, I hadn’t paid attention to which stock black power cord came with which amplifier — in my mind, all power cords sounded the same. We switched power cords and listened again. To my great shock, some sonic attributes I had ascribed to the amplifiers over the previous two week of listening were actually sonic characteristics of the AC cords. And this was a difference between two stock AC cords. Since that experience I’ve paid close attention to the AC powering my audio system, power conditioners, and power cords. When I built my house, I specified three separate dedicated 20-amp lines, which are grounded via a copper rod in the earth just outside the listening room and isolated from the rest of the house.

~ Robert Harley