Hello,
As the subject states I'd like to know if there's a known way to get stereo sound out of a IIgs without having to take up a slot with a stereo card. Detailed information on all the stereo sound options seems a bit limited; currently I have a Drew ][ TDX card, and it's nice, but a slotless solution would be nicer. 
Whilst I don't know of any slot-less stereo cards for the IIgs, it is certainly possible.
The only thing that *most* cards use the slot for is +5V and -5V which could both be derived elsewhere.
Stereo cards that have stereo recording and/or MIDI capabilities would use the various data lines as well, but these are not the norm when thinking of IIgs stereo cards.