Help with DIY microphone please

[internecine]

so ive done a bit of searching and ive found that for the diy'er the best value is the panasonic mw-61a capsule, correct?

now, what i havent been able to find is a tutorial on how to build a mic using this part.

furthermore, i would need it to be self powered, or build a cheap/simple power supply (i guess thats called phantom power)

i have no problem using a design that uses a 9v battery. The only use i would have for this mic is RTA and MLS measurements with apps such as speakerworks of lsplab.

since i will be trying to keep it on the cheap i would be using somthing like a m-audio transit since i wont need power from somthing like a m-audio mobilepre.

if anyone can point me in the right direction, or if i should be posting in a different fourm, please let me know.

thanks and i hope i dont get too many flames

 

[Cal Weldon]

Hi, I have moved this over to everything else from loudspeakers.

 

[cuibono]

hi there,

The panasonics are nice mics. I use them a bit nowadays. Check out linkwitzlab.com,

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

it is what I have been using. This is pretty easy to breadboard and make a stereo mic. I've done some binaural recordings with them, and they impress everyone. Look into the yahoo mic builders group, they do a lot with this capsul, and diy microphones in general. Also check out http://homerecording.com/bbs/ they do more front end audio stuff.

 

[internecine]

dont need stereo at this point and dont think i will any time soon.

what about a preamp, is this the same as phantom power?

 

[error401]

dont need stereo at this point and dont think i will any time soon.

what about a preamp, is this the same as phantom power?

No, it's not. Phantom power is common in professional equipment and involves applying a 48VDC bias to the balanced lines in an XLR connector (+48V on each signal line, referenced to the ground). Because XLR connectors carry a differential signal, this common-mode voltage has no effect on the signal itself and allows the cable to carry power to the remote device as well without extra conductors. It's traditionally used for exactly this purpose, to bias condenser mics (though applying 48V directly will destroy this particular type), though other equipment can also take advantage of this power source. Most professional mixers provide phantom power on their mic inputs.

A preamp simply buffers and amplifies the usually small signal coming from the microphone up to line level, and doesn't imply phantom power (which is probably not too useful for this application).

 

[dangus]

http://mysite.verizon.net/tammie_eric/audio/preamp/preamp.html

 

[internecine]

so i now know what im doing about the mic

now is the question of the necessary equipment i will need after that.

if i get a m-audio transit, then i need a pre amp

if i get a m-audio mobile pre, then that covers both the interface and the preamp

am i getting this right?

is there any cheaper way to do what i am looking to do?

 

[Svein_B]

1) Byu the Panasonic WM-61A from Digikey or on Ebay.
2) Make a power supply:

3) Plug it into the mic input of your notebook PC, or use the M-Audio Transit (or similar)
If you use the M-Audio Transit you may be able to omit the separate power supply since it has [I believe] built in power for electret microphones.
4) Make a suitable stand
I just canibalized a cheap PC mic with a new capsule:

SveinB.

 

[error401]

Thanks for the post by the way, reminds me to put one or two of these guys on my next DK order. Would definitely be handy to have around since the cheapie computer mic I have now is absolutely horrible.

 

[internecine]

so a preamp is not necessary?

or is a preamp prefered but the 9v power supply is good enough?

 

[Juergen Knoop]

the mic-input of a soundcard usually provides the power supply and the preamp for a electret capsule.
http://www.diyaudio.com/forums/showthread.php?s=&threadid=99324
regards

 

[internecine]

so it sounds like the best thing to do now is to get the mic and try it out to see if it works with my built in sound card. (using an imac)

i should also use a loop back cable to check the FR of the soundcard itself. if thats screwy, then i should get the m-audio transit.

if the m-audio transit does not supply power, then rather than a preamp, i could just wire it up to use a 9v battery as posted above.

so i see people using preamps wtih the panasonic capsule mic, any reason why you would do that over the simple method posted above?

 

[Svein_B]

Yes, some soundcards and boxes (M-Audio) provide power for electrets microphones equivalent to the 9V battery circuit above. The notebooks am using do not.

The built in power feed is however using lover voltage, and is more likely to be noisy. The 9V cirvuit could therefore be better in any case.

The level is suitable for the mic input of soundcards.
A separate pre-amp will most likely provide better S/N ratio, and lower distortion / better linearity if for demanding applications.

SveinB.

 

[internecine]

m-audio transit appears to supply 5v of power for electret mics.

i assume that the quality of this power would be equal or better than the simple 9v power supply, but probably not quite as good as a dedicated 9v preamp.

so now i need to determine if the input of my soundcard is any good, ive done some searching and the quality if the transit is quite good.

so, how would i determine the FR of my sound card? first find out if its full duplex then loop the output to the input and play pink noise? what kind of app would do this, for mac preferably, but i could also use a pc program.