Piezo pickups often need help with a preamp. >add more$<
Contact Microphones,1)condenser AKG C411 the less costly generally dont, if you have a Mixer to run thru, just like a freestanding mic.
2)Dynamic Schertler , not cheap at$375, but, no phantom power requirement, no preamp,[as is, the Sound is Great!] and a $15.00 matching transformer converts to 1/4 hiZ to plug into all that sorta stuff,Volume pedal, fuzzwa, acoustic guitar amp directly , and is 'a Keeper' #not installed, to shift to better sounding mandos (and guitars) over time.
Although, You can always 'holler' thru a free-standintg mic too, though,so consider that.condenser are wider frequency response usually.
writing about music
is like dancing,