Test - Amp volume vs Mic volume

This video compares two scenarios:  In the first segment the volume on the amp is all the way up and the volume on the harp microphone is barely cracked.  In the second segment the amp volume is on 4 and the microphone volume is all the way up.

My phone is in the foreground running the RTA app to show the relative loudness. The amp is a Mission Chicago 32-20 and the mic is a 1959 Shure 440SL with 99B86 CM element.

The two segments sound similar.  To my ear the segment with the amp all the way up was less lively and not as full sounding.  The amp tipped into screaming feedback if I turned the mic up the slightest bit, so this is about as loud as I could get in this scenario.  That was my benchmark volume for the comparison.

In the second scenario the amp is on 4 with lots of room for more volume, and a greater range of tonal inflections.

I'd heard about the "amp all the way up" thing over the years and decided to test it after hearing a jammer do it at Ziggies the other night.  I think there is a good reason it is not very common.  The traditional way sounds better.

Please pardon my noodly playing....