I’ve used Room EQ Wizard to measure the taps of my solid state power amps before. All of the measurement utilities (sweeping, I/O selection, graphing, digital level setting) is self contained in the application and it’s free. I didn’t save the results though.
My SD Powerstage 170 didn’t look all that flat with its tone knobs at noon. I measured a flatter response with my Behringturd A800 power amp, so I moved onto using the A800 for modeling anmplification and making IRs.
If you feel like digging deeper, I suggest using REW so you don’t have to search through a plugins interface to figure out the default graphical smoothing settings.