Tweakers' Asylum Tweaks for systems, rooms and Do It Yourself (DIY) help. FAQ.

---

[ Follow Ups ] [ Post Followup ] Thread: [ Display  All  Email ] [ Tweakers' Asylum ]

---

[ Alert Moderator ]

---

A murky subject...

Posted by Al Sekela (A) on September 1, 2007 at 15:21:25

In Reply to: Ground wire placement in DIY power cords posted by mitch2 on August 31, 2007 at 21:13:50:

The third wire, called "ground," is there as a safety measure to connect exposed metal of the audio equipment to the neutral wire (and to the earth) at the circuit breaker panel. It is not supposed to carry any current unless there is a power fault in the equipment.

Unfortunately, the metal parts connected to this wire have some close proximity to the audio zero reference ("audio ground"). In some equipment there is a direct connection. Any voltages developed in the safety-earth wire due to electrostatic or magnetic induction are coupled to the audio zero reference and can corrupt the audio signal because they appear to be a part of it.

If the audio equipment power supply drew current in the form of a 60 Hz sine wave, this would not matter much: the induction would be low and the coupling could be made to be small. In the real world, most audio power supplies draw current for only part of the AC sine wave. This means the induced voltage in the safety-earth wire can have lots of high-frequency components, and can corrupt the audio signal more easily.

Counter-wrapping the safety-earth wire can reduce the induction of power supply noise into this wire. Depending on your equipment, this can improve the performance.

This post is made possible by the generous support of people like you and our sponsors:

Parts Connexion

---

[ Top of Page ] [ Contact Us ] [ Support/Wish List ] [ Copyright © 2025, Audio Asylum, all rights reserved ]

---

[ General ] [ Speakers ] [ Tubes ] [ Vinyl ] [ Digital ] [ Hi-Rez ] [ Video Asylum ] [ Cables ] [ Tweaks/DIY ] [ Music ] [ Films ]

---