NEC code for 70V audio

[utimgr]

Anyone familiar with the section in NEC that discusses 70V audio? I was told it was grandfathered in, such that you do not need to have it in conduit, but looking for the article number to reference that.

 

[resqcapt19]

That may be a Class 2 system and not require a raceway, but it could also be a Class 1 system. Take a look at Article 725 in the NEC.
Don