I need some advice about connecting a two-lead electret condenser mic (which I’m about to order) to a preamp, the final design of which is yet to be settled upon. (I have a two-transistor preamp, but I have a nice little circuit for an op-amp preamp that I may build.) Because I have a 12VDC power source available near the preamp, I’m using that to power it. (A small amount of hum is acceptable in this application.)
Most ECMs are rated for around 2—3VDC up to a max of 10VDC, and I understand that a current limiting resistor in series with the power is necessary…usually noted as 1k ohms or 2.2k.
The 10 volts max limit would seem to rule out my 12 volts idea. On the other hand, I read something elsewhere that says to use the higher 2.2k resistor if the voltage source exceeds 12 VDC.
Now I’m thoroughly confused about whether or not it’s a good idea to try to use 12 volts. If it’s possible but hard on the ECM, I’d rather try to reduce the voltage to the ECM. Does a voltage divider seem reasonable in this situation? The ECM uses about .5mA. Perhaps a couple of 12k resistors in series to ground, and I could tap 6VDC from between them?
Thanks
Most ECMs are rated for around 2—3VDC up to a max of 10VDC, and I understand that a current limiting resistor in series with the power is necessary…usually noted as 1k ohms or 2.2k.
The 10 volts max limit would seem to rule out my 12 volts idea. On the other hand, I read something elsewhere that says to use the higher 2.2k resistor if the voltage source exceeds 12 VDC.
Now I’m thoroughly confused about whether or not it’s a good idea to try to use 12 volts. If it’s possible but hard on the ECM, I’d rather try to reduce the voltage to the ECM. Does a voltage divider seem reasonable in this situation? The ECM uses about .5mA. Perhaps a couple of 12k resistors in series to ground, and I could tap 6VDC from between them?
Thanks
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