And has been used as a connector for multichannel audio by several manufacturers (mostly in recording gear), but with several different pin out arrangements.
I tried again in 2008 and scored with a (hopefully) proper 6 channel one from TheCableCo. It cost me a staggering US$168 shipped to Australia, so my joy was near endless when it just plugged straight in and worked. After that I upgraded to the Xonar sound card which took straight RCA inputs.