How can i get rid of radio signals from my amplifier

1) Remove all input cables, check if noise goes. If so investigate connected devices and wiring quality.
2) Try a different mains socket.
3) If there's a headphone socket, try removing the speaker wires and see if the noise persists. Radio can be picked up on speaker wires -- ferrite core chokes on the speaker wires might help.
5) If none of this produces any change it may be a dry solder joint -- you need a service engineer.