Question: Can I remove the power module from my microphone?
Answer: If a microphone includes a power module, then the power module is absolutely a necessary component for wired operation. The power module cannot be bypassed by reterminating the microphone with just an XLR connector. By doing so, you will cause damage to the microphone when phantom power is applied. Also, removing the power module will void your warranty.
Condenser microphones need DC power to operate. That is an operating difference between dynamic microphones and condenser microphones. Some condensers are powered directly by phantom power, while others may be powered by a battery installed in the microphone. Still others need a power module. The power module that is attached to some condenser microphones provides several important functions. First, it converts the 11–52V DC phantom power into a smaller DC bias voltage in order to power the FET impedance matching circuit inside the microphone. Some power modules also provide low-frequency roll-off, convert the signal to the proper impedance, balance the output and even supply battery power if phantom power is not available.
While on this subject, what is phantom power? Phantom power is voltage of 11–52V DC sent down the microphone cable to power the preamplifier of a condenser mic capsule. Phantom power requires a balanced microphone cable, which has three conductors: Pin 1 is ground, Pin 2 is audio positive, and Pin 3 is audio negative. Most microphones produce a positive voltage on Pin 2 when sound pressure is applied to the diaphragm.
The 11–52V DC is applied across Pin 1 and Pin 2 – and at the same time across Pin 1 and Pin 3. The term “phantom power” was assigned because if you take a measurement across the two audio lines – Pin 2 and Pin 3 – you find 0V DC. Also, phantom power voltage does not affect the mic signal in any way.
We hope you found this post helpful. Be sure to check back each Wednesday for a new “Question of Week.” And, remember, if you need assistance with your Audio-Technica gear, please contact our Audio Solutions Department. We are always happy to help!