Condenser mic pickup

I made my first CBG and was surprised at how well it sounded acoustically. Not loud, but good tone. I put in a traditional piezo. And it got that nice twang to it.

I decided to experiment to see if I could get a mic with a better frequency response so I went to Radio Shack and bought one of their condenser Mic elements for about $2.50 to put in my next CBG.

A condenser mic, of course, needs a power supply and one can usually get by with a battery wired in series with the mic. But I decided to wire up a slightly more sophisticated circuit that could be used with any amp. I found a great discussion of the mics, and digrams here:
http://www.epanorama.net/circuits/microphone_powering.html

The circuit I used looks like this:

                                  10 uF
                                 + | |
    +---------------------+--------| |--------------> to amplifier
    |                     |        | |
    | (positive lead)     |               
    |                     +----------/\/\/\---------+
   MIC                              2.2 kohm        |
    |                                               | +
    | (ground lead) (-)                          -------
    |                          (battery 9v or so)  ---
    |                                               |
    |                                               |
    +-----------------------------------------------+----> ground

The sound is great. All the fullness of the acoustic sound but louder. 
I wired a volume pot in series with the output and a mini-switch to 
the battery lead so that the battery won't run down if I leave the 
guitar plugged in.  I used a 9v battery but the mic is so hot that a 
couple AAs might be a better choice.

Mark

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Replies

BenBob November 5, 2010 at 6:32pm

Very cool! I always wanted to try one of those in an acoustic. I think I remember seeing that circuit back in the RMMGA days.
Tres Seaver November 5, 2010 at 12:34pm

Thanks for the writeup -- looks like a cool idea. FWIW, you can use the "camera" icon to inline the images:
Bluesheart November 5, 2010 at 11:49am

I bet it sound great. I was wondering if a small mic would not be a better choice than a piezo. Great work and thanks for the info.
Michael R Cossey November 5, 2010 at 7:38am

Thanks for the info Mark..I'll have to give these a try at some point.......Also is the mic on the inside like I've seen with some?...Mike

Mark Reaney said:
Not much feedback. I mounted the little PC board beneath the center board with a small piece of velcro so that I could move it around and experiment with the orientation of the mic. Seems to work best when it is pointed down towards the floor....Mark

Michael R Cossey said:
Is there much feedback to these? I've seen some add on controls that have Piezo, condenser and mag all in one......Mike
Mark Reaney November 4, 2010 at 11:58pm

Not much feedback. I mounted the little PC board beneath the center board with a small piece of velcro so that I could move it around and experiment with the orientation of the mic. Seems to work best when it is pointed down towards the floor....Mark

Michael R Cossey said:
Is there much feedback to these? I've seen some add on controls that have Piezo, condenser and mag all in one......Mike
Michael R Cossey November 4, 2010 at 7:46pm

Is there much feedback to these? I've seen some add on controls that have Piezo, condenser and mag all in one......Mike
Doctor Steve November 4, 2010 at 7:18pm

Wow. Totally new idea to me. Would love to hear what it sounds like. Not much more difficult than a basic piezo.

This reply was deleted.