Docedison:
Lefty.. there is a small issue there... what happens if some genius plugs a real AC adapter into the connector... some times it is best to start with the right hardware to begin. That was why I kept hammering the switched 'low level' audio. someone suggested putting some current through the jack so it could be "sensed", the major issue with that is in "Sensing" when the speaker was plugged in... the sense current would need to be an appreciable part of the main audio signal. I am of the opinion that it is usually bad work to try to save a few pennies or Worse... Time by these types of "Methods". In the time we have spent trying to solve the issue he could have the right installed and on to the next job.Doc
Certainly something to take into consideration. I was more trying explain that some circuit jacks contain switch contacts in addition to the signal they route into or out of the jack. Such switch contacts can be very useful as in the case of a headphone jack that not only routes sound to the headsets, but just by the act of plugging in can be made to disconnect an otherwise active speaker that wires to totally different speaker connections on the same device. Switched jacks can be quite complex, but can solve many otherwise tricky problems.
Lefty