No audio output from external input

Hello Folks -- I have a mac mini (solo intel) 10.4 OSX. I have no audio output when attaching an external input source like a CD player or ipod to the input jack on my Mac Mini. Audio output from ITunes or movies clips in IPhoto works fine. I have checked the cables and connections. I have checked the "sound" location in System Preferences to make sure the "built in output" source is selected. The input volume display shows that the audio input is being registered. I have checked "system profiler" in the Utilities folder in Applications to make sure the "built in output" AKA headphone outlet is recognized.

I have the "Soundflower" App. installed but turned off.

Does anyone have an idea as to why the audio output from the internal sources like ITunes and IPhoto music clips work but the audio output from an external input source does not? Is there some software or a driver required for audio output from an external source that is not required for audio output from an internal source? Any info appreciated --- Jeremy1

Summarizing - using your Mac as an amplifier.

You need an application to stream the sound. Garageband will do it. How to Use a Mac Computer as an Electric Guitar Amplifier - Associated Content - associatedcontent.com (just substitute whatever you're using for audio in). [Note: I cannot test this, I've tossed G'band.]

Summarizing - using your Mac as an amplifier.

You need an application to stream the sound. Garageband will do it. How to Use a Mac Computer as an Electric Guitar Amplifier - Associated Content - associatedcontent.com (just substitute whatever you're using for audio in). [Note: I cannot test this, I've tossed G'band.]