hmmm
Yeah, I guess there is no reason for the 1/8" jack to be seen as substandard, except that all my other stuff uses 1/4". I think I'm going to go with the RCA-1/8" converter route, and try that, since the 1/4" headphone output from my Tascam has kind of a shaky volume pot...
As far as what I meant, the following sentence on homerecording.com confused me:
"Well, guess what, 98% of the time there's a MIDI interface hidden in this connector. You need a special $20-or-so joystick-to-MIDI conversion cable to access it, but then you can hook up keyboards and all kinds of stuff right to your sound card."
It's in the FAQ section on soundcards. When they say you can hook up keyboards and all kinds of stuff, that makes it sound like more than just MIDI. Is maybe a Midiman the answer here? I know that's more than $20, but if it would help me make the most of what I got, maybe it'd be worth it. Or maybe if I'm willing to go there, I should just get a better soundcard, huh? I think if the RCA thing doesn't work I'll give up and get a new soundcard.
Thanks for everyone's help.