Primo EM173 Microphone Capsule

Should I use an EM172-Z1 or EM173?

• The EM172-Z1 and EM173 are physically identical, they share the same housing and diaphragm.
  
  
• The EM172 has a 2 wire connection and is the easiest to use, it can be wired directly directly to most domestic recorders which have 3.5 mm microphone sockets and supply plug in power.
  
  
• The EM173 has a 3 wire connection, its the 3 wire version of the EM172. It has no internal resistor from the source to ground, if you add a 100 ohm resistor between source and ground on the EM173 its identical to the EM172, of course you can select a higher value for less sensitivity.