I've got a low profile, custom RSA/Kobiconn female balanced > SE 1/8" (3.5mm) adapter for sale.
For adapting your RSA balanced headphone cable to a single end source. The RSA end is a genuine Kobiconn part, and the 1/8 jack is a Neutrik gold plated unit. Both quality parts. The connections inside are soldered point to point, with silver bearing solder. There is no hook up wire inside. The area around the leads are sealed/strengthened with epoxy, and double shrink wrapped. Solidly built. This adapter is brand new, never been used.
I built this for myself, for an upcoming portable rig, then plans changed. So I don't need it. Asking $20, basically just the cost of parts/shipping/Paypal fees. $20 total.
Please see my excellent trader feedback! Thanks for looking!