If you decide to do the Linkwitz mod to the Pansonic WM-60AY electret microphone elements http://www.linkwitzlab.com/sys_test.htm (about 2/3 of the way down in the section labeled Microphone), I suggest you carefully take a look at the battery box schematic for it and the one posted on http://home.earthlink.net/~gottapes/micdiyers/main.htm in the Wiring Schematics- Binaural Stereo Mic section. With the modded Panasonic mics, the power supply in the battery box has to be reversed in polarity. If used with a "normal" one such as the battery box from MicDIYers or "mic (plug in power)" input of your recording device, there will be a lot of hissing type noise and the microphone's sensitivity to low frequencices is decreased when compared to the battery box/mic input being used with a normal mic. I've made a battery box with a DPDT switch to toggle between normal and reversed power supply and it works fine with microphone and line inputs (recorder's own power is bypassed when using a battery box) and normal/modified mics. I've also tried wiring a modded Panasonic mic reversed so that it would work with the "normal" battery box setting/mic input, it's a small mic for non quality recording such as quick notes, lectures etc (in mono obviously), and the signal being inverted because the new output is tied to ground doesn't seem to be a problem. If use with a stereo pair, I doubt it'd be a problem since both will be in phase, but I'm not sure and haven't tried since I have made the appropriate changes to my battery box to accommodate both versions of microphones.
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6/30/01 at 2:11am