Electret microphone pre-amplifier 1U Tile
E-TRET is a pre-amplifier for electret microphone elements. It can be used with our Electret Capsule (M1), or other electret sensors.
There are two jacks: electret input and audio output in addition to a single gain knob.
Features:
http://erthenvar.com/store/tilemodules/etret
No info about availability.
$30