PS Audio Trio P 200

I picked one of these up a few months for a system I was putting together ($400 used-with upgraded RCA connectors). It works great, but I noticed that I don’t get any volume until about 9 o’clock, which seems a bit weird. Also the knob is not very secure, I figure I could probably open it up and tighten a set screw or something.

But is that normal with the volume? I has nothing to do with inefficient speakers, I have had multiple different ones hooked up to it.