Determine Your Mains Polarity

Van den Hul Pole Checker

One of the most important and most often forgotten "tweaks"

One of the most important and often forgotten "tweaks" for improving the playback of an AV or stereo system is to check and correctly apply the mains polarity.

Any honest audiophile can do that quite easily themselves. And with a little skill (or good relationships), this can even be done for free. All it takes is a pole checker and some labor. Such a pole-checker is a simple device that in fact indicates what residual voltage there is on the cabinet of the sound equipment. This residual voltage is caused by the power supply, or rather, the power supply in combination with the earthing of the device. We will spare you the technical details, but just assume that all audio equipment can benefit from being properly connected to the mains. Only amplifiers with switching power supplies (class D amplifiers) do not suffer from a "wrong" connection to the mains.

How do you handle something like that? Simple: you can borrow a pole checker.
Or one buys one, for example from Van den Hul. They are not that expensive, but then the tweak is of course no longer free.

  1. All equipment must be disconnected from the mains, and also from each other (that is very important, all interlinks but also speaker cables must be disconnected for a while).

  2. Plug in the first device, turn on the device, and touch one of the screws on the back of the cabinet, or one of the interlink terminals with the pole checker.

  3. Read what value the pole checker indicates.

  4. Switch off the device, insert the plug in the wall socket in reverse, switch the device on again, and measure again. The lowest measured value indicates the correct connection.

It is useful if you determine in advance which connection of the socket the voltage is on. Mark the "hot side" with a permanent marker or with a small tip of nail polish. Do that right next to the hole, but also do it carefully. Also on the plug of the just checked appliance it should be marked which pin should fill the "hot" side of the socket. This will prevent the obligation to measure everything again in the future.

If all equipment is correctly connected to the mains in this way, the cables can be reconnected and the result can be heard. The most frequently heard improvements are a calmer soundstage, deeper bass, and a larger soundstage due to the increased detail. Sometimes the differences are subtle, sometimes they are nothing short of spectacular.

Using a multimeter to determine the correct phase

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