That is correct... but no MP3 player I've ever seen has both types of jacks on the unit itself.

 

i havent seen one either with both but thats why you need a strong power source to give you that extra oomph - or your battery would be dead quickly and then totally out of luck

-with the ipod i have not noticed any difference between being plugged in or not- but my old player there deff was one ( icant remember what it was)

 

...a cheap player obviously

 

Tip for those of you looking for this particular cable - you can get them on eBay for like $6.00. They are $18+ at places like Best Buy and Circuit City.

 

I rely on monoprice.com for my cables. they have a plain 6 foot for 66 cents, or a fancy retractable one for 2.23

Audio Cables - RCA / 3.5mm