Hi all,
First post here, I recently disassembled a Panasonic tape recorder and ended up doing tests with the built-in mic. It works, but seems to need 6.3 Volts of power (based on the diagram which I've attached here)
I guess, I would need some sort of 6v phantom power circuit or I may be completely off as well - does anybody have any leads or experience with this type of situation?
Thanks,
Adrien
First post here, I recently disassembled a Panasonic tape recorder and ended up doing tests with the built-in mic. It works, but seems to need 6.3 Volts of power (based on the diagram which I've attached here)
I guess, I would need some sort of 6v phantom power circuit or I may be completely off as well - does anybody have any leads or experience with this type of situation?
Thanks,
Adrien
Well the mic input circuit will probably be at a lower voltage, say 5V, as its no doubt regulated to remove motor noise. Electret mics are fairly liberal about their power, there are many circuits on line, you need a well decoupled supply, a dropper resistor (in this circuit its 3k3), and take the ac signal off with a capacitor.
Electret mics have an internal n-channel JFET that lowers the output impedance from gigaohm levels to kiloohm levels, so you are basically interfacing to that JFET - the resistor is the load for its drain.
Electret mics have an internal n-channel JFET that lowers the output impedance from gigaohm levels to kiloohm levels, so you are basically interfacing to that JFET - the resistor is the load for its drain.