External sound problem on macos X


I have a imac 233 a series with a external aplifier marantz and kef sound system. In macos 9.04 or 9.2.1 No problem with external sound. In macos x 10.1 10.04 or puma i cant not ear the external monitor sound. Audio external is connect in the audio out. Is a bug? only in the imac? I no have solution in the control panel sound on X. thanks.::(
The origional iMacs (rev A-D) cannot use the external sound port on the side of the machine in Mac OS X. Try plugging the speakers into a headphone port. It should work. Hope that helps. :)