Capsule


16mm cardioid electret without internal FET


Circuit Board

24C02 EEPROM

2K serial memory



(unmarked chip)

Probably CMedia

CM108B

USB CODEC


USB connection




MAJOR COMPONENTS ON CIRCUIT BOARD

LMV721  Op-Amp

low noise 5V operation


2SK596 JFET

on other side of printed circuit board


Mic volume control

on other side of printed circuit board


Dual Op-Amp

headphone amplifier

CIRCUIT BLOCK DIAGRAM

What can we do to improve this mic? It’s well designed for the low cost parts employed. I replaced the 16mm capsule with a 25mm CM012 electret which sounds better for my voice, and added a jumper wire from the case of the volume control to ground on the PCB. That helped with hum pickup. Not much else can be modded. There are USB mics built around fancier CODEC chips with multiple higher sampling rates and greater bit depths, but those are completely different circuits.