General Description

The Shure Model R115 is a replacement cartridge for both the Shure Model 55SH Series II UNIDYNE and 586 Series UNISPHERE A dynamic microphones. When properly installed in the microphone, the R115 will provide performance equal to that of the original cartridge.

55SH Series II

  1. Remove the four 6-32 x 1/4-inch Phillips head screws securing the die-cast case front to the die-cast case back. Remove the case front.
  2. Remove the four 4-40 x 5/16-inch round head screws and lockwashers securing the cartridge assembly to the case back.
  3. Carefully withdraw the black plastic cartridge assembly from the case back, taking care not to stretch or break the three leads.
  4. Remove the four 7-19 self-tapping Phillips head screws from the rear of the cartridge assembly and remove the rear cover from the housing.
  5. Using a low-wattage soldering iron, unsolder the three leads from the cartridge to be replaced.
  6. Remove the old cartridge. Keep the aluminum retaining ring.
  7. Place the aluminum retaining ring over the rear of the R115 replacement cartridge, and carefully solder the three leads to the cartridge (see Figure 1).
  8. Carefully insert the cartridge and ring in the black plastic housing, replace the rear cover, and secure it with the four self-tapping screws previously removed.
  9. Insert the cartridge assembly in the case back and secure it with the four round head screws and lock-washers previously removed. Engage the two lower (toward switch) screws first to align the assembly.
  10. Replace the case front and secure it with the four Phillips head screws previously removed.

Figure 1: 55SH Internal Connections