Logic Pro 9 How to mimic a fast to slow tape heavy vox effect?

I was exposed to a technique used particularly for vocals years ago in a recording session.
I think this was pioneered at Abbey Road studios and know it was used in the 80's to give singers heavier sounding voices, particularly to get that heavy baritone sound.
It's a simple case of recording with the tape running quicker than normal, then when it is played back at normal speed the vocals sound heavier/weightier/lethargic even.
I'm using Logic 9 and wondering how I could replicate this technique? or if there is something else entirely different I can do to achieve the desired effect?