Good but annoying noise. No exchange possible.

I have the reviewers Andreas (see in the silver version) agree. I find the amplifier actually very good, but is also with me a high cheeping / whisper on the left channel clearly heard when the music is off (ie including combinations between the titles or silent passages). That bothers me so much that I will return the amplifier. In some English reviews this problem is described.
I would like my unit traded in the hope that only individual devices are affected. But this is not possible because Amazon sent only for Grandview and no replacement equipment supplies.
The only way that I would remain to return the device and must be ordered again. That's for me, but no reasonable solution, because the price has now been increased from 96 to 126 euros. I find nowhere a contact directly to Grandview.