Ben Bradley wrote in message . ..

It appears you want four separate channels. There's that Turtle
Beach Santa Cruz four-input consumer-grade (as in inexpensive) card,
go look for it...

Thanks for that. It looks like a good card for my purposes. It turns
out it's marketed as the Videologic SonicFury here. And it turns out
that no-one is selling new ones here any more. I'll see if I can find
one second hand.

Also, I've discovered you can solder a sound card analog CD cable to
the audio jack of your choice. I might do that instead.