Until recently, I used plumbing solder and flux for electronics. They work fairly well, but the RepRap motor controllers refused to go together without more coaxing. There were a few bad solder joints on one driver that killed it.
My dad found me some solder in the basement, but I was reticent to use it without testing. I made an adapter that connects a computer to a stereo to test the solder (and to use).
From previous scrapping, I had all the parts needed: two female RCA connectors, and a 3.5mm male audio jack. I'd planned to make a 6" extention cable, but changed my mind and just assembled them deadbug style.
I only had white (left) and yellow (video) RCA's, so the gizmo uses a yellow plug for right. Sue me.
The adaptor went together easily. I bent the pins a bit, and just soldered them together. Electronics solder is much easier to use than bulky plumbing solder.
That's it for this experiment, and the new adaptor is playing music in the background.