hi there,
not really a BELA specific thing, but since i use it for BELA i thought i'd share.
i just built this: https://paulinthelab.blogspot.com/2012/04/balenced-to-line-microphone-preamp.html
mic preamp on vero and it works wonderfully and sounds great! (no noise unless i really crank the pot fully open at which point the output swings at about -10 to 10v :-) this is with a cheap 12v switching power supply, you could probably improve the sound by using a non switching supply. also the circuit should work from 9 to 15v.
note that this is almost exactly from the INA217 datasheet schematic.
i substituted the OPA606 with an OPA2604 which works flawlessly. note that you have to change the vero a bit since the OPA2604 is a dual opamp while the OPA606 is a single (different pinout)