The first thing I bought after I got an iPod Shuffle was a car stereo with an AUX input jack on the front panel:
Soon, I found it was inconvenient to have the iPod at the end of a cable:
What I wanted was to plug the iPod straight into the AUX input, like this:
I shopped around for a male-to-male, 1/8 inch, stereo adapter.
I looked everywhere.
Nobody had one.
Nobody.
So, I went to Al Lasher's Electronics in Berkeley, and picked up a pair of 1/8 inch stereo plugs ...
... discarded the sleeves ...
... trimmed the connectors ...
... fit them together ...
... and soldered them:
To seal the contacts, I got some epoxy putty ...
... cut off a little bit of it ...
... mixed it thoroughly ...
... and covered the plug with it:
After waiting for it to harden ...
... I cleaned off the extra with a razor blade:
I thought it would look a little more professional if the shape of the epoxy putty were closer to a cylinder.
So I got some sandpaper ...
... and started removing putty; it was easy to stop at the right place, because the metal parts of the plug were harder than the putty:
After it was more or less cylindrical, I gave it a final shaping in a "lathe" (aka my electric drill):
Ta-da!
Here it is connecting the iPod Shuttle to the stereo's faceplate:
And here it is again in situ:
I'm really pleased with this; the iPod's controls effectively become just some more buttons on the stereo.