Excerpt from the Madrid Information page @
http://www.MadridMan.com/mad-info.html :
Electricity
To use your U.S.-purchased electric-powered equipment, bring a converter and an adapter. The electrical current in Spain is 220 volts, 50 cycles alternating current (AC); wall outlets take Continental-type plugs, with two round prongs.
Here's one of the European standard plug (also for Spain). Check to see if your iPod has automatic, internal switchable power capabilities. If so, great. You can then simply use a simple plug adaptor. (see below)
[img]
http://us.st11.yimg.com/us.st.yimg.com/I/electrical-supplies_1911_639217[/img]
[img]
http://us.st11.yimg.com/us.st.yimg.com/I/electrical-supplies_1911_655733[/img]
The above (#1/#6) is what I use for my US-bought laptops (which come with it's own power converter) and my electric shaver (also has automatic, internal power switching)
If NOT, you'll have to get a transformer/electrical converter which you should be ableto find in any Radio Shack in the USA (if there are any still in business).
Good luck and happy travels!
Saludos, MadridMan
