power to lavalier


2013-02-01 12:40 am
So I have a countryman emw lavalier microphone. it is the version designed to work with wireless systems, but I dont have the wireless system. I would like to be able to hard wire the microphone to my preamp, but I do not have a power supply for it. I have a direct box with a 50k to 600 ohm impedance matching transformer in it that I would like to use to balance the signal. my mic is rated for 1.5-24V and an impedance of 1500 ohms.

Can i just power it with a 3V battery and a couple of electrolytic capacitors, using the direct box in reverse to balance the mic? I've heard that it could but it didn't work for me. could the problem be that it is dropping the impedance down too low? since the transformer has an 1:83 winding ratio, it'll drop the impedance down to about 18 ohms?

If this isn't supposed to work, is there another option? countryman wants to charge me $140 for the xlr connector by itself or else i would just go with that option. I really need the mic this weekend so i'm hoping to get this figured out soon.

If you are wiring it in directly, why does it need to be balanced? The value of a balanced line is that it can run long distances without picking up a ton of noise or attenuating your highs. But to transform it to balanced only to convert it back an inch later doesn't seem necessary to me.

Does your preamp have phantom? We could probably adapt that. Otherwise, no reason you couldn;t just duplicate teh battery power the transmitter pack used to provide. The mic signal won't know the difference whether it goes to a preamp or to a transmitter.