Topic: Basic Mic Powerng Question

[stevetoney]

Does a microphone draw much more current when it's being used during a loud show vs. just recording ambient sound in my living room?

Reason I ask is that I've done some battery testing to see how long each of my older batteries will power my rig by just hooking up my 702 up with the mics all setup at home (with phantom on of course) and running the juice out of the battery. 

Just wondering if there would be much less run-time when I'm recording at the live venue at loud volumes.

[Javier Cinakowski]

Does a microphone draw much more current when it's being used during a loud show vs. just recording ambient sound in my living room?

Reason I ask is that I've done some battery testing to see how long each of my older batteries will power my rig by just hooking up my 702 up with the mics all setup at home (with phantom on of course) and running the juice out of the battery. 

Just wondering if there would be much less run-time when I'm recording at the live venue at loud volumes.

I don't know the answer to this, but my uneducated guess would be that the current draw is the same for any amplitude.  If anything you would think it would draw more for a quiet source...

[DSatz]

I've never seen any phantom-powered microphone draw more current while putting out higher signal levels.

If it did, that might be problematic. The more current a microphone draws, the greater is the voltage drop across the pair of resistors (6.8 kOhms for 48 Volts) in the phantom powering circuit, and thus the lower the voltage that the microphone would see coming in. That's the weird thing (or OK, a weird thing) about those Earthworks mikes that draw 10 mA--drawing anything more than about 7 mA actually makes less power available to the microphone circuit.

--best regards

[Church-Audio]

Does a microphone draw much more current when it's being used during a loud show vs. just recording ambient sound in my living room?

Reason I ask is that I've done some battery testing to see how long each of my older batteries will power my rig by just hooking up my 702 up with the mics all setup at home (with phantom on of course) and running the juice out of the battery. 

Just wondering if there would be much less run-time when I'm recording at the live venue at loud volumes.

The standard for phantom power is 10mA max.. Most mics will not change because the gain of the internal preamp is fixed therefor if there is no increase in gain or "work" that your asking the preamp to do there should be no increase in current draw. And most good microphones have a regulated supply that helps further stabilize the power coming into the microphone to decrease any voltage swing that might effect the performance of the microphone it self.

Chris

[stevetoney]

Thanks for the answers guys.  Not being a tekkie, I kinda figured as much, but it's something that I wondered about.

[oleg]

if you run hotter signal more leds would blink on 722  so you would drow much higher  current 
for mic loud signal not change anything