Does the Choice of Outlet on a Mains Distributor Affect Sound Quality?

Continuing from the Zonotone 6NPS-3.5 Meister power cable article. Some of you who have been swapping power cables in and out for comparison listening may already have noticed this, but are you aware that plugging the same cable into different sockets on a power strip can make it sound quite noticeably different, even with exactly the same cable and equipment? In some cases, the difference between socket positions can actually be larger to the ear than the difference from polarity.

Even when people are particular about the type of power cable, the power strip, or polarity, the question of “which cable goes where?” tends to get decided rather casually — based on whatever order things were plugged in first, or how far the cables reach. But this “where exactly to plug in!?” turns out to be surprisingly important. Within my own limited experience of trying a handful of different power strips…

Sockets closer to the cord end of the power strip (the side connected to the wall outlet) have a stronger sense of energy
The further a socket is from the wall outlet, the more strongly the power strip’s own sonic character comes through

Broadly speaking, I feel there is a tendency along these lines. Note: the impression may vary depending on the nature of the power strip and, in particular, the type of cable connecting it to the wall outlet.

With a power strip like the J1 Project PT-4 — one that improves the perceived S/N — the further back the socket, the quieter the background of the sound becomes, and you get the PT-4’s characteristic dense, tight imaging. On the other hand, expressiveness feels more neatly organised and a touch of vitality is lost, though the frequency response takes on a flatter character, which is not at all bad in its own way.

With the Ortofon PSC-3500XG currently connected to the TAG McLaren 60i, unless it is plugged into the socket furthest from the wall outlet — as shown in the photo — the PSC-3500XG’s colouration and lushness becomes too overbearing and the sound turns rather odd.

Conversely, when the integrated amplifier’s power cable is connected to a socket close to the wall outlet, the sound becomes more lively in relative terms, but in exchange the surface of the sound grows rougher and the overall refinement suffers. The character of the PS Audio Prelude XPD/1.8 Mk2 — the power cable running between the power strip and the wall outlet — also becomes more audible. Since I personally rather like the distinctive sound the J1 Project PT-4 produces, it seems best to connect the component most strongly influenced by the PT-4 — that is, the integrated amplifier — to the socket furthest from the wall outlet.

The CSE CX-63A, which I use for the sub-system and digital piano, is a power strip with a smooth, bright, moist sound with a faintly warm tonality. In this case, the rear sockets (right side in the photo) make the power strip’s character come through even more strongly, but the downside is that the drive and momentum of the sound is reduced, it becomes subdued, and the impression is one of insufficient information. This is not a power strip with a sharp, high-resolution character to begin with, but in order to balance its smooth character with an adequate sense of quality, I find it generally works better to connect both the amplifier and the player to sockets closer to the wall outlet cable — or to choose something in the middle as a compromise. (The wooden cube plugged in at the upper left is the Audio Spice ACC18.)

Based on all of the above, as a general rule it seems best to connect amplifiers — which need a sense of perceived power — to sockets closer to the wall outlet, while components where you want the power strip’s character to come through strongly, or where you want to improve the perceived S/N, are better placed further away. That said, exactly which position is most appropriate will ultimately vary from system to system depending on each component’s sonic tendencies and the overall tonal balance, so this is no more than a rough impression. In practice, things are case by case for each individual setup, so for those who are interested, by all means experiment and see what works.

One word of caution, though. Repeatedly inserting and removing plugs weakens the grip of the socket contacts and gradually changes the sound — so if you are after a tight, well-defined sound with good transient clarity, rather than going through endless trial and error, it may be better to approach the whole exercise with enough focus to find the best position in as few attempts as possible.

Of all the power cables for high-end audio currently available domestically, the one I find myself most drawn to at the moment is probably PAD’s AC-IOTA… ← The copy on the distributor’s page reads like literal poetry from Jim Aud, which is very PAD somehow. Part of it is that I already use a PAD CRYOMAG on the wall outlet in my main system, but I also remember hearing an AC Dominus that an acquaintance brought along for a listen once — it had this unrealistically sweet, lingering quality to it, quite fascinating. A sound that was agreeably pleasant to the ear in a way entirely removed from any kind of hi-fi realism. That extreme I would rather decline, but if the AC-IOTA could offer just a touch of that PAD nuance while still maintaining spatial resolution and a sense of clarity, it might be rather interesting to try. Note: I did eventually acquire the AC-IOTA.

Speaking only of the audio equipment I have at home, the component that most strongly reflects the character of a power cable or power strip — sonically speaking — is, in most cases, the integrated amplifier. (I cannot say so with certainty since I do not have a separate pre/power setup, but I would guess it is the power amplifier rather than the preamplifier.) Next comes a one-box CD player or DVD player or similar playback device, and last of all a standalone D/A converter. The tendency seems to be that components with higher power consumption show more clearly audible differences. For example, if the system as a whole lacks a sense of drive, using a power cable with a conductor of over 3.5 sq mm — such as the Oyaide TUNAMI — on the amplifier can compensate to some extent for dynamic expressiveness. Conversely, if the sound is too aggressive or you want to reduce bass heaviness, using a power cable of 3.5 sq mm or below that is rated for soundstage resolution, frequency flatness, and transparency rather than low-frequency weight on the amplifier should help rein in any sense of the sound overflowing its boundaries.

For components with low power consumption such as CD players, rather than fitting an extremely thick cable, using a thinner-conductor cable with a good reputation for tonal quality, transparency, and resolution — or a power cable that brings out delicate nuances — should help add depth and realism to the sound of the system as a whole. (Note: everything written here is based solely on the author’s own subjective evaluation within the author’s own environment, and is not a guarantee that any of it will apply in individual setups.)