PHASING To test two microphones for proper phasing, connect them to an amplifier and talk or sing into them while holding them three or four inches apart. The sound from the speakers should be the same when talking into either microphone or directly between them if they are in phase with each other. If the sound drops drastically, or if a dead spot is found when talking between the two microphones, they are out of phase. All microphones should be tested in this manner to insure that they are in phase with each other. To change the phase of a microphone, the microphone cartridge leads must be interchanged (see Figure 2 ) . This should be performed by your dealer, the Shure Factory Service Department, or other qualified service personnel.
IMPEDANCE Your Model PE57 is a high-impedance microphone. If cable lengths over 7.6 meters (25 feet) are required, or if the microphone is to be connected to a low-impedance input, it will be necessary to transform the microphone line to low impedance. Shure Model A95 Series Line Matching Transformers are available for use in those cases. These transformers provide a proper impedance match between a high-impedance lnicrophone line and a lowimpedance input and are supplied with various input and output connectors.
