I've got a second question also : I am intended to buy a new receiver as well. But.. I have two pairs of speakers in my living room and one pair in my kitchen. This receiver should be connected to these three pairs of speakers. This seems to be rather difficult. How should I proceed and wich receiver to buy ?
Thanks !

There are 4 ways you can go.

Just string wires along the baseboard or somewhere from the amplifier to the speakers.

You can snake the wires through the walls. Perhaps down through the floor, through the crawl space or basement and back up. You can also go up to the attic. Interior walls have 14 1/2'' X 3 1/2'' spaces between the studs. It isn't too bad to fish wires through them. Beware of other wires, pipes, air ducts, etc. Exterior walls can be a pain because they usually are filled with insulation.

Most electronic places sell wireless adapters.

There are also adapters that send the audio through the house wiring. I think wireless is taking over.