Gotcha. I've used those on several derailleur bikes with good results. Note that they are marketed as being good for "single-ring use", i.e. 1xX drivetrains, and the 130 BCD version flat-out says "(not intended for singlespeed use)". I think that's an admission that since these are cheap chainrings meant for derailleur bikes, they might not necessarily be round enough for picky fixed-gear riders.

But like [MENTION=164476]Scrodzilla[/MENTION] says, just ride your bike for now. My fixed-gear is a conversion built up from old road components, too, and sometimes I notice drivetrain noise and sometimes I don't. If you haven't already, you might see if oiling your chain (and then wiping it down thoroughly afterward) quiets it down.