How to phase audio devices?

How to phase audio devices?

There is often debate about the direction of connection of audio devices, and thus their electrical phasing. In this guide, we offer you some information on the interest of phasing your equipment in High-Fidelity. We also offer you a "scientific" method to determine the "correct" power phase of your audio devices.

1. The goal of phasing your Hi-Fi devices

A reversed power phase has a more or less negative influence on the music restitution and the performance of the devices.

Our experience has demonstrated us that power phasing has more influence on phono preamplifiers, DACs, amplifiers or preamplifiers with a standard power supply (transformer + rectifier + filtering).

Devices such as DVD players or CD players using a switch mode power supply are less concerned by this phenomenon.

The gain obtained is of course variable and usually affects several registers. By phasing the devices, we can therefore generally expect to obtain:

- Better dynamics
- Better restitution of micro-details
- More precise and stable sound scene
- More fluidity
- Less noise
- Less aggressiveness

In our opinion, it is difficult and presumptuous to try to find the "right" phase at the ear, particularly if the Hi-Fi system is composed of 3 or 4 elements. It is certain that if your Hi-Fi installation is composed of an integrated amplifier and a turntable, it is quite easy.

However, in the case of a rather complex system, composed of a vinyl record player, a phono preamplifier, a preamplifier, an amplifier, a drive, a DAC, a network player, etc., this test by ear is tiresome and, above all, it can easily raise doubts.

2. The equipment necessary to phase the audio devices

To phase the audio devices, it is necessary to equip yourself with some elements. Which are the following:

1) A small voltmeter that can measure an alternating voltage from 0 to 250 V

To phase audio devices - voltmeter

2) A phasing tester screwdriver

To phase audio devices - tester screwdriver

3) A power strip equipped with Schuko-type sockets

To phase audio devices - power strip with Schuko sockets

4) An EU/US adapter to connect the socket without touching the ground

To phase audio devices - EU/US adapter

Of course, know that it is possible to make the measurement and determine the phase with a standard French power strip. However, the grounding pin will prevent you from reversing the plug if this is required for correct phasing.

3. Handling for phasing audio devices

In order to enjoy the benefits of this handling, it must first be ensured that the devices have passed their running-in period. This period can, following the device, vary between 50 and 200 hours.

Also, unlike others, we do not promise you incredible changes after this operation because some people may not hear the difference between before and after... However, a good phasing ensures a perfect optimization of your Hi-Fi system and a 100% operation of it.

To phase audio devices, the operation is the following:

1) Turn off all devices
2) Disconnect all connections between the devices (interconnection, digital...)
3) Place the adapter on the power cable plug of the measuring device
4) Disconnect the plug and turn on the device
5) Place the voltmeter on Volt AC
6) Put one touch point on the ground pin of the strip and the other one on a screw of the chassis or on the ground of an RCA plug (outside)
7) Read the value
8) Repeat steps 4 to 7, having first reversed the direction of the mains plug

The proper direction of connection will be the one that indicates the smallest value. You will, of course, have to repeat this operation with each of your devices.

Tip: once this is done, we recommend that you mark the direction of the phase on your power strip with a colored sticker or varnish. For this, you will have to detect it with the test screwdriver. The hole where it lights up corresponds to the phase, the other is the neutral. After finding the right connection direction, just locate the marker on the power plug of the device.

In the long run, in case of disconnection or change of power strips, this operation will have the advantage of regaining good sense without having to repeat all the measurements.


We hope that these explanations about phasing audio devices in High-Fidelity will help you to optimize your Hi-Fi system. If you would like further information, our technicians are at your disposal by phone (0 810 810 121) or via our contact form.