We've seen plenty of chunky mains cables over the years, but few rival this one for sheer bulk. Encased within an attractive three-colour nylon-braid sleeve, it measures a whopping 13mm in diameter.
The claimed reason for the thickness is AudioQuest's 'Counter-Spiral HyperLitz' construction, an arrangement that uses several individually insulated solid-core conductors for live, neutral and earth.
One result of this construction is that the cable's capacitance is higher than most, which will cause a slight change in the characteristics of the cable/mains transformer circuit and hence, possibly, the sound compared to what you get with regular cables.
Another potentially significant factor is the use of ferrite noise absorbers near both ends of the cable. The connectors are good-quality types, and well fitted.
With suitable precautions taken against lighter pieces of kit being dragged off the shelf (this is a very springy cable!), we tried NRG-3 with several components, both sources and amplifiers. In most cases it has an effect, though it isn't always entirely beneficial.
Yes, there seems to be a reduction in grain in the sound, especially with CD players, but there's also a slight change in tonality with several components that we're not sure we entirely love.
Sounds in the lower midrange seem a little subdued, and this makes it harder to latch on to the line of melodies that use that register, as many do. It might act as a slightly unpredictable tuning tweak for systems that are a little proud in that area, but we find it oddly unsettling.