Hi I can't truthfully answer your question completely but Apple sockets and plugs, in general, are not totally compatible with most mass produced sockets/plugs made mostly in China. I do know that a friend of mine who makes guitar amps with a jack plug on a lead for attaching an mp3 player so that you can play backing tracks through the amp at the same time as playing lead guitar, uses a special jack plug as he says the normal run of the mill jackplug will not work with Ipods very well. I think it is something to do with manufacturing limits on Apple gismos being tighter than on eastern made products. As for the PTP, I do find that when plugging leads into the earphone socket to connect to my hi-fi I sometimes have to insert and remove the plug a couple of times to get it to work. It may be something in the PTP that adjusts the impedance to match whatever is being plugged into it rather than a physical misfit. Sorry if this sounds a bit vague and long winded but several of the items you mention are Apple while the others have sockets of an unknown manufacture so it would take a lot of research to get a complete answer. regards cliff