A lot of noise on the new DD unit

[mojster666]

Today I quickly connected my new DD unit. There was a very annoying noise. Radio reception is ok, but at low volume, it is very annoying noise. The same situation is with the music on the USB flash. If the volume is set to "0", then there is no noise. If the volume is set to "1", noise is heard. Also, the "2", "3" and "4" are noisy. When I set the volume to "5" then the music is louder than noise.
In short, listening at low volume is very disturbing. Is there something wrong with my DD unit, or is this normal?

[Banjo]

I don't know what is wrong - but it is certainly not normal. Mine has no strange noises at all.

[HarryM1BYT]

No noise here either.

If I turn the volume up to full, particularly when the satnav is booting up, I can just about hear digital noise interference with the engine not running, but other than that nothing untoward.

Does the noise appear with engine running or not running?

[mojster666]

Experiments like this. The engine is turned off. The doors are closed. Now you have silence in the car. Set all tone controls to zero (loudness off, bass to 0, treble to 0). Set the volume to 1. Now set the bass to +1. Appears very annoying noise (like "sssssssssss"), which is audible up to volume 5 (and beyond). Noise appears as soon as any sound control is activated.

This only happens on my DD unit, or even on yours?