I kept reading online that the arrangement was the same and the iPod and also the Zune so there are loads of cheap cables and adapters out there that work.
After lots of searching I found a number of cables that looked like they would work, but since they were all cheap no specifications for the wiring were listed.
From the Schematic (http://www.raspberrypi.org/documentation/hardware/raspberrypi/schematics/Raspberry-Pi-B-Plus-V1.2-Schematics.pdf) the arrangement needed from tip to base is.
Tip - Audio Left
Band 1 - Audio Right
Band 2 - Ground
Base - Composite Video
It doesn't really matter if the audio connections are reversed as you could just swap the leads, but getting the ground or the composite in the wrong position means no video would be output and in the case of ground no audio also.
So, I went mad and took the plunge to buy a £2.00 adapter from eBay and see if it works.
Here it is plugged into the Raspberry Pi Model B+
|RCA/Composite video adapter for Raspberry Pi B+|
It covers the HDMI port which isn't a problem. As, when I'm using composite I'm not using HDMI.
I am delighted to say it works perfectly. The wiring is correct. I plugged it into a television and up popped the display from my RetroPie install. Playing Double Dragon on the big screen.
|Double Dragon played over composite with stereo audio|
Meaning for £4.00 all in you have an adaptor for B+ to connect to composite and analogue audio as well as the required connecting cable.
I like that it is a 2 piece configuration as a composite cable can have other uses. I spliced one before to work with an Arduino and the TV-out Library.
Gathering more bits.