I was sat in the car with the engine off and put the Bolero on to play from an SD card. As soon as I hit play I can hear hissing but before the song even starts playing - so it isn't the files. To test this I stopped a song and turned the volume off - as soon as you turn the volume up one notch from minimum (or off) the hissing fades in.

 

Can't work out if it's doing it with the engine on or not because of the engine noise.

 

Anyone else got this?

I can hear a fan when the Bolero unit is switched on and had assumed it was a fan on the back of it, to keep it cool when switched on.  I can hear it when it is switched on and no matter what media source is selected.  It does not get louder or quieter with the volume, so I thought it might be a fan unrelated to the actual audio output.

 

Do you think this might be what you can hear as well?

Edited 11 May, 201412 yr by skGOda

No it's definitely coming from the speakers as if I turn only the rear speakers on it then comes from them.