I am trying to get audio out from a PC into a hold message system.  Direct connection into
switch, should work from headphone jack.  Output from a portable CD player works, plug-in
portable radio works, even headphone output from my laptop.  Output from the sound card
headphone jack doesn't work?  Ideas?

Also tried powered USB external audio card.

Had some luck with an external amplifier and its 8 ohm output for unpowered slave
speaker.  Faint, but there.

Thanks!