The Phantom of Power


[ electret mic ] [ powering ]

Make an adapter cable. Here’s the description of an existing (Sound Professionals recommended) solution:

(from Q/A about Audio Technica’s AT8538 Power Modules):

  • Convert the 11 – 52 VDC phantom power into a smaller DC bias voltage used to power the FET impedance matching circuit inside the microphone.
  • Provide low frequency roll off (such as HVAC rumbles, outdoor wind sounds)
  • Convert the signal to the proper impedance
  • Balance the output.
  • The power module is a necessary component. Microphones that use this power module are fixed-charge back plate, permanently polarized condenser.

Two of these can be used with the mice [ SP-XLRM-MINI-3-PHANTOM ]


It might just be that the world is conspiring against my measuring my HRTFs. Either way, this world is not really against my accessing an existing database though (CIPIC database, Media Lab)(Side note, I wasn’t able to load the 1994 .DAT files into MATLAB the last time I tried (endinanness issues?), CIPIC’s files got loaded with numbers!)

The latest problem is phantom power (sampling rates are tormenting the horizons, in the meanwhile.) I just cannot get the mice and Becks to work together. Though I am hopeful that Becks did not burn the mice (please be true!), Becks is a little too strong (48V) for the mice (~2V). R-01 worked just fine (2V), but Becks won’t pick anything from these mice.

To resolve this isse, I need to know more of the mice specs. I (finally) met Dr Inan today (after professor Anderson’s meeting), and got the suggestion that Panasonic capsules might be the ones inside these mice. I got quite excited by this, found WM-61A easily (the frequency responses looked similar!), and emailed Sound Professionals to make sure that these were the ones. They got back later today, and said that, “We have these custom made for us.

Still, I suppose that they would be similar to the other condenser mics available in the market. And this is about time my microelectronics class got to FETs!

I also asked Sound Professionals about the Becks problem and they recommended using an adapter cable: [ SP-XLRM-MINI-3-PHANTOM ]

This sounds like a circuits lab design problem. I am liking this semester.


2 thoughts on “The Phantom of Power

  1. Pingback: It would be fun to make a recorder! | Audio Sketches

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