left and right channel wrong

I played a testrecord yesterday (decca) I noticed that te left and right channel are not according to wat they should be. The voice on the left side (read channel) says he's talking in the right speaker and otherwise.
I checked my cable connections to te amp and to te speakers, and the wringconnections to the cartridge and of course the interlink to the amp. Everything seems oke yet the left and richt channel are mixed up. Any suggestions.
Thanks