Volume?

I recently acquired a CJ Sonographe SG 3 with an Audioquest PT 7 arm and a Blue Point cart. I am using it with a Marantz 2226 receiver and Paradigm Studio 40 speakers. I'm new to vinyl so I have a question. I notice that some albums seem to play louder than others and also it seems like I need to turn the volume up around the 12 o'clock position to get decent playing levels. I do have the TT plugged into the phono input with the ground attached. Any advice or is this the norm? Thanks again for any advice.