Thumbnail HTTP?

With the_post_thumbnail I am able to retrieve <img src=”http://etc.jpg&#8221; width=”000px” height=”111px”>

Is there a way to retrieve only the http://www.site.com/image.jpg

I am trying to allow others to download the thumbnail image, but the displayed thumbnail is resized with add_image_size, so I am trying to link a download button to the original http image of the same thumbnail, full size.