Managing Recording Volume

I have an i-Mac and a Pro-ject USB turntable. In recording a vinyl album, I cannot adjust the recording volume. In a few songs I have noticed a tiny bit of clipping. Looking at the manual, it says that you cannot use the recording volume slide. It says to use the system control panel and adjust the volume there. The only thing I see is the mixer board and moving the slide on it does not appear to affect the recording volume. How do I adjust the recording volume?

Macs have little or no provision for changing the volume of a USB device. I think the instructions were pointing to the Mac System, not the Audacity System.

Apple (upper left) > System Preferences > Sound > Input. There should be a slider there and a blue ball sound meter.

If the overload is restricted to one album and then only here and there, you might get away with it. Those can be caused by cat hair pops and clicks and might go away when you run the vinyl cleanup tools.