These recording go back to aroun 2003. I brought a few mics to a Carlos Colina's house and we tested them out.
The amp we used was a Fender SF Princeton Reverb from around 1970. The knobs were set to Volume=3-4, Treble=3, Bass=8, Reverb=2. Most of the mics had volume controls, but if the mic did not, I rolled back the volume to the point where it did not feed back. The MC-101 element was not very loud so I turned up the volume on that mic.
The amp has that natural Glassy sound from using high voltage on 12AX7 tubes. Most harp players would want a Bass amp with less treble and more bottom end, rather than turning down the treble knob.
This is a Shure SM58 in a taillight shell with an impedance matching transformer. Use this mic as base point for comparison. Both Carlos and I thought that this mic injected the least character into the sound. This is just a good mic, cupped well with a loud harp.
Classic JT-30 with a NOS MC-151.This is what you expect when you play harp. A responsive mic with lots of definition and the ability to control the overdrive.
American Microphone D-4 "salt shaker". Nice mic with good dynamic element. Lots of bass.
Hohner Blues Blaster. This has the Japanese Kobitone crystal and doesn't sound half bad.
Weak MC-101 element in a taillight shell. Not very loud but buttery smooth.
JT30 with a 1-meg volume control
and a NOS MC-101 from my stash.
Astatic T-3 with a Black Label Shure Controlled Reluctance element and an Impedance matching transformer.
Atatic T-3 with a NOS MC-127 ceramic element.
Teisco mic with a Shure 99A86 CM
and an impedance matching transformer.
Shure UniSphere I PE-56 with volume control.