I just ordered a few LM3916 IC's that I intend to use to build a LED audio meter. My plan is to connect it to a stereo I've built using TDA7240 amp IC's (20W).
My approach is pretty straight forward, I'm planning to use the typical application schematic out of the spec sheet, which you can see here:
The typical application design is for a 0V to 10V VU meter. The amp supply signal is from my mp3 player. So it seems clear to me that I don't hook the signal from the mp3 player directly into the LM3916 IC, as it's nowhere near 10V. So is the signal source I put into the LM3916 simply the speaker output from the amp? The IC's are cheap, but I'd prefer not to burn any of them up if I don't have to...
This topic has been covered here many times. Use Google Advanced Search with www.electro-tech-online.com on the Domain line to search for previous threads.
I answered these questions a few minutes ago on another website (Electronics-Lab). I showed part of my Sound Level Indicator project there and explained how the LM391x works.