Q. At Videomaker’s advice, I got myself a balanced microphone and balanced cable to reduce interference from electromagnetic noise. I know I need an adaptor to get the signal from the XLR cable to the mini-plug my camcorder needs. Now I understand that these adaptors come in several varieties, and that getting the wrong one can cause phasing problems. Could you tell me exactly what I need?
A. It seems like this should be less complicated, but unfortunately, it is not. You will place your adaptor, not between the microphone and the XLR cable, but at the other end of the XLR cable . One end will plug into the XLR cable, the other into the camcorder. In addition to changing the type of connector leading to the cam, this adaptor will unbalance the balanced signal coming to it from the XLR cable. This is good only because your cam is made to accept only an unbalanced signal. It will still receive the noise-reducing benefits of your balanced microphone and XLR cable for the entire length of the cable. Only the short cable in the adaptor itself is unbalance and more vulnerable to radio-frequency noise, so buy an adaptor containing as short an unbalanced cable as is possible for your uses. The good news is that for most cams, the price for this adaptor will run toward the lower end of the $20-$55 price range.
Before shopping, find out whether the microphone jack on your camcorder is stereo or monaural. You will find this information on the spec sheet in your owner’s manual. This step is very important. Much unhappiness has resulted from plugging stereo plugs into mono jacks and vice versa.
Second, determine whether your balanced microphone is monaural or stereo. If the microphone is mono and the adaptor is built to receive XLR stereo (or vice versa), it will create a phasing problem that can ruin your audio or even make your audio disappear (see explanation in the October 2002 Tech Support).
Finally, look at the XLR jack at the end of the cable you need to plug into the camcorder . Typically, this will be a male 3-pin XLR connector.
One last caution: Some older DV cams need "DC voltage blocking" built into their adaptors. Some retailers of audio equipment have lists of those models requiring this adaptation.