Depends on the gain of your amp and the output of your source. This is known as the "Bolero Test"
You could try it from the direct line out of your source with no volume at all, but you need to use a cd to see how loud it's going to get, hence the Ravel Bolero cd is ideal as it starts off very quiet and builds so you can then gauge if you are going to blow your amp.
Cheers George