nMP: Headphone extension, can't switch Sound Output

[snouter]

I put a mini extension cable in the headphone out port so I can plug headphones in and out easily from behind the monitors, but I can't switch the audio out to the Cinema display if the extension is in, so I have to move the monitors and disconnect the mini extension and that defeats the purpose.

Am I missing something?

 

[demars]

I put a mini extension cable in the headphone out port so I can plug headphones in and out easily from behind the monitors, but I can't switch the audio out to the Cinema display if the extension is in, so I have to move the monitors and disconnect the mini extension and that defeats the purpose.

Am I missing something?

I have an nMP and this works OK for me. I have a transmitter for wireless headphones permanently plugged into the headphone jack, and powered speakers plugged into the speaker jack. I can switch between them using the Sound panel of System Preferences, or more easily by option-clicking the Volume icon in the menu bar (you have to enable the volume control in the menu bar to do this).

USB-based audio can also be handled in this way.

If this isn't working for you, you might want to post more details about exactly what goes wrong.

 

[snouter]

With the extension mini cable in the headphone jack, Headphones Built-in is selected in the Control Panel.

I can't select LED Cinema DisplayPort or Display Audio USB.

If I unplug the extension cable, I can.

So if I want to use headphones I have to move the monitors and plug in the cable and if I want to use LED Cinema speakers, I have to move the monitors monitors and unplug the cable. Headphones switches to Internal Speakers and I can choose LED Cinema Display.

Seems like I can't manually choose an output if something is plugged into the headphone jack?

EDIT: Grr. Ok I tried the other jack, the Line Out Audio line-out port and I can manually switch things.

tl;dr don't plug headphones into the headphones jack if you want to retain manual output selection control.