vumeter after preamp or after amp??serial or parallel?

I'm building a LED vumeter, now i have a doubt, do i have to put it after the amp or the preamp? and i have to connect it in serial way (like an amp. meter) or parallel (like a voltmeter)? i think these questions are quite stupid lol but i have the doubt and i don't want to screw it up.
Thanks to everyone?