LED VU meter question

[scwhiteley]

Hello!

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:

http://www.national.com/images/pf/LM3916/00797101.pdf

The full spec sheet is here:

http://www.national.com/ds/LM/LM3916.pdf

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...

Thanks!
-Chad

[sivan_and]

add a preset at the input to set the level..the final LED should be red colour should come on when the amp clips !!!!

[gmphadte]

National gives good front end circuits for these. Search for its applications on their site.

[col]

I have been looking into this a bit too. A couple of interesting links:

LED Audio VU Meter

http://www.ozitronics.com/images/k89.jpg
http://www.ozitronics.com/docs/k89.pdf

I actually don't want the full meter though and would prefer a clipping light, to do this accurately seems to be a bit more complex.

I'm wondering if it would be possible to use the LM3915 with one multi-color LED.

col.