SOLVED! Buzzing / humming noise from Pro-Ject Essentials II phono stage to Pro-Ject Phono Box ground

Описание: This seems to be quite a common issue with the Pro-Ject Essentials II turntable. The phono cable is pre-installed at the turntable end therefore there is no way to swap it for another cable. The buzzing / humming noise can be heard through the speakers (measured at 50Hz using an oscilloscope). This points to an AC interference.

To cut the long story short, the issue is caused by the Pro-Ject Phono Box pre-amplifier being unearthed; because it is powered by an unearthed DC power adaptor.

The solution was simply to earth the whole Phono-Box + phono cable setup by connecting a wire from the ground lead screw to the earth connector of a spare power socket.

Please fast forward the video to the later part to view the fix and the difference that it makes.

UPDATE: There are 2 other ways to solve this problem, which can be viewed in my new video:    • 2 more solutions for solving Buzzing / hum...  

UPDATE: On newer turntables e.g. Debut Carbon EVO, the ground lug on the phono output is connected to the negative (-) terminal of the DC motor. This means the whole system can be earthed by using a linear power supply where the earth cable is actually connected to the transformer and the negative terminal. An example of this is the Pro-Ject High Power it.