# DIY Microphone with Panasonic WM-61 electret cartridge



## AUDIO

Hello,

I intent to make a microphone with a Panasonic WM-61 electret cartridge.

Has anybody an experience for that ?

Thanks.


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## Bruce

Yes,

I will try to attach some photos of the items when I get home tonight.

I also have photos of a small 9V battery operated mic-preamp to go with it.


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## Bruce

Did this about 8 years ago, but here are pics.

Note, the metal tube is a brass tube.

I should also note that these are not photos taken by me, but are instead photos from the website I ordered 
the parts from 8 years ago (no longer online).

http://www.hometheatershack.com/gallery/index.php?n=1382


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## BrianZ

I realize this is an old post, but I'm wondering if anyone has more recent experience with a DIY mic and preamp using the Panasonic WM61 electret condenser mic, and any tips on how to use with REW. I thought it might be a fun little electronics project, and I found this page also has preamp designs, though I'm not sure which is simplest most appropriate...
http://www.johncon.com/john/wm61a/

I already have a usable external USB sound card with Line In and Line Out (Diamond xs71U, http://tinyurl.com/a7eufjc , tested and gave a nice curve with REW), so would like to make both a mic and preamp circuit with 3.5mm jack, using one of the above designs or perhaps this one...
http://www.madaboutsound.com/prod_det.asp?cid=112&sa=cf&ctid=4
I notice this site also has a calibration file, though I'm not sure if it's REW-compatible (file type is ".frd").

Looking for any DIY guidance/suggestions/tips, even if it's to say it's not a good idea & why. I like saving money and enjoy spending the time to build something if there is a reasonable chance of success, particularly since my interest is more for curiosity and learning, though I realize I might end up with something I could actually use for tweaking my sound system. onder:

Thanks


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## problemaddict

I don't really have an answer for you, but I'm going to build one of these too using the instructions from Siegfried Linkwitz. He's got some info, a circuit diagram, modifications to the capsule, and a link to the Mic DIYers forum. Check here:

http://www.linkwitzlab.com/sys_test.htm#Mic

Good luck!


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## BrianZ

Thanks for the link. I've seen some other references to the Linkwitz method too, including these interesting threads in a DIY forum...

http://www.avsforum.com/t/1325052/lilmikes-mic#post_20221544
http://www.avsforum.com/t/1328136/measurement-mic-shootout-emm-6-wm-61a-rs-33-2055-audyssey

Since I last posted, I also found an interesting page here about the various ways that an electret mic may be powered and illustrating the variety of situations one might encounter for various sound cards, etc:
http://www.epanorama.net/circuits/microphone_powering.html

Before going to the trouble to build the Linkwitz mod, I thought I'd try using my 2-wire Audyssey mic first (speaker setup mic that came with my Onkyo receiver). At first I had no success trying to use it directly, but then I found the above page, so I used the circuit shown under the heading "Battery powered electret microphone" on that page to build a small box with just the 10uF capacitor, 2.2kOhm resistor, and a couple of 3.5mm jacks and on/off switch, which I was able to use for plugging in my Audyssey mic, and then cable that output into my sound card line-in jack. It gave me decent levels that I could use with REW to generate curves and compare speaker responses and tweak some of the crossover settings in my receiver, all using mostly parts I already had laying around. Also wondering if this same approach would work for a PC mic I have which might have three wires. The Audyssey mic is the small 1/4-inch size, but the PC mic is about 3/8-inch.

I may still try the Linkwitz method though.
Thanks again.


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