I've been working on a microphone...

  • Thread starter Thread starter crazydoc
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OneRoomStudios said:
...How hard was it to make/understand how to make?...

But how dificult is it to grasp the concepts needed to construct a simple mic? I would greatly appreciate it if you could point me in the direction of a good site with some info on the topic or anything of the sort.
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It's really not hard at all. Of course, a lot of it depends on your prior background and interests. I got into electronics when I came back from Viet Nam and wanted to be a rock star. Of course for this I needed an amp, so I bought a Heathkit and made it - this got me comfortable with soldering, parts, etc. The real beginning of my electronics education was when it blew up and I had to fix it. From there I started building simple amps, preamps, reverbs, and such. As my limited understanding grew (and it's still damned limited - the only thing I know is Ohm's Law, but that can get you through 90% of it) I started taking parts of different circuits and combining them. When integrated circuits became affordable, that was heaven! I even designed and built a frequency spectrum analyser, and the damned thing worked! (And that was 25 years ago, when the only ones available were mechanical.)

So much information is now available on the web, for free - just for the asking - that getting into this kind of thing is a piece of cake. We used to have to buy books and go to the library. :)

Here's some links to get started. Also, do google searches - you'll get more back than you can ever absorb. Good luck. If you have any questions, just post - help is just a mouse click away.

http://mp3forkidz.com/mic/
http://www.discovercircuits.com/M/mircophone.htm
http://www.rason.org/Projects/projects.htm
http://www.tonmeister.ca/main/textbook/index.html
http://www.planetharmonica.com/ph2/VE/TMI-micUK.htm
http://www.prodigy-pro.com/forum/index.php
http://www.commlinx.com.au/schematics.htm
http://sound.westhost.com/index2.html


In any case, you're my hero and have inspired me to actually try to build one of my own. Oh and I love the cookie tin - adds just the right touch of class.
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Hero is hardly appropriate - doing this poses no danger or threat to anyone or anything, except possibly my marriage. But I do appreciate the compliment. Go for it - the worst you can do is release a little smoke. (And you do need to know that the secret of electrical devices is smoke - they need the smoke to run. If you let the smoke out, they don't work anymore.)
 
Thanks for the info! It's all great and now I have a place to start. I think I'm just going to start off with a dynamic just to work on my soldering skills. Does anyone know where I can buy parts such as dynamic capsules, potentiometers, 1/4" jacks, etc...? Oh and I'm in the US if that makes a difference. Thanks again!
 
Just pushing this to the top....I was hoping to get started soon on the mic, but I still can't find a place that sells dynamic mic elements. So if anyone knows of any, PLEASE let me know! Thanks a ton.

-Peter
 
I have no idea of how or whether it works, but that thing looks hilariously cool.
 
OneRoomStudios said:
Thanks for the info! It's all great and now I have a place to start. I think I'm just going to start off with a dynamic just to work on my soldering skills. Does anyone know where I can buy parts such as dynamic capsules, potentiometers, 1/4" jacks, etc...? Oh and I'm in the US if that makes a difference. Thanks again!
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I am not sure that dynamic mic would be a good start, as I never saw capsules sold separately. Also, a lot of things in dynamics are relied on acoustical arrangement. To 'sharpen' your soldering skills I would suggest first to start with some kind of kit--pink noise generator, for example--very usefull thing to check speakers and mics. Then, try to modify some cheap Chinese mics. After that you will get much more confidence and... probably won't need our advise anymore ;)

<Does anyone know where I can buy parts such as dynamic capsules, potentiometers, 1/4" jacks, etc...?>

In US You can get all these stuff at:

www.digikey.com
www.mouser.com
 
OneRoomStudios said:
Thanks for the info! It's all great and now I have a place to start. I think I'm just going to start off with a dynamic just to work on my soldering skills. Does anyone know where I can buy parts such as dynamic capsules, potentiometers, 1/4" jacks, etc...? Oh and I'm in the US if that makes a difference. Thanks again!
Click to expand...

I am not sure that dynamic mic would be a good start, as I never saw capsules sold separately. Also, a lot of things in dynamics are relied on acoustical arrangement. To 'sharpen' your soldering skills I would suggest first to start with some kind of kit--pink noise generator, for example--very usefull thing to check speakers and mics. Then, try to modify some cheap Chinese mics. After that you will get much more confidence and... probably won't need our advise anymore ;)

<Does anyone know where I can buy parts such as dynamic capsules, potentiometers, 1/4" jacks, etc...?>

In US You can get all these stuff at:

www.digikey.com
www.mouser.com
 
OneRoomStudios said:
Just pushing this to the top....I was hoping to get started soon on the mic, but I still can't find a place that sells dynamic mic elements. So if anyone knows of any, PLEASE let me know! Thanks a ton.

-Peter
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I don't know of any DIY dynamics or parts either. If you want to build a mic, try an electret one using the panasonic capsules. Unfortunately the most widely used one seems to be unavailable (WM-60AY) But others would work, especially for a first attempt. Here's the listing of capsules available at digikey
http://www.digikey.com/scripts/dkse...S&Ref=220658&Cat=30081907&ColumnSort=0&Page=1
http://www.digikey.com/scripts/dkse...S&Ref=220658&Cat=30081907&ColumnSort=0&Page=2
I'd think the WM-61A would be an acceptable substitute - just less sensitive.

Here's a couple of links to mics built using these or similar capsules.

http://prosoundweb.com/recording/tapeop/buildmic/buildmic_16_1.shtml
http://www.eclectic-web.co.uk/index.php?jump=mike/electret_a.htm
http://sound.westhost.com/project93.htm

and even this harmonica mic that I posted before is worth a first shot if you can find an old dynamic mic and take the capsule out of it.

http://www.planetharmonica.com/ph2/VE/TMI-micUK.htm
 
CanopuS said:
Fab! I don't understand more than about 30% of the words, but you have my respect sire :)
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I second that! You are doing more to educate yourself, Than I have done in a long time!:)
 
crazydoc said:
I don't know of any DIY dynamics or parts either.
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I'm sorry, but what does this mean? I understand the Do-It-Yourself concepts. I was wondering about the dynamic parts and elements? What are these? And how are they connected? And how might they apply to condenser mics? similar electronics/elements? I really don't know. Thanks.

I'm not trying to HiJack this thread. So if Anyone who wants to answer this, wants to email or PM me that's fine! Thanx Again!
 
So, CrazyDoc, have you named your new creation? I think it should be called the "Shortbread" microphone.
 
Reggaesoldier said:
I'm sorry, but what does this mean? I understand the Do-It-Yourself concepts. I was wondering about the dynamic parts and elements? What are these? And how are they connected? And how might they apply to condenser mics? similar electronics/elements? I really don't know. Thanks.

I'm not trying to HiJack this thread. So if Anyone who wants to answer this, wants to email or PM me that's fine! Thanx Again!
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Go to the first two threads in the mic forum (the stickies) - they will explain it all.

Here's a quick and dirty
http://www.modernrecording.com/articles/soundav/link19.html

In a nutshell:
A condenser mic uses a membrane or diaphragm as a part of a capacitor - as the sound waves move the membrane farther from and closer to the backplate, the capacitance changes correspondingly, and the rest of the mic circuitry changes this into a useable electrical signal to send to the preamp.

A dynamic mic uses a coil of wire attached to a membrane. This coil is suspended in a magnetic field, and when sound waves move it in this field a corresponding current is produced, which is then sent to a preamp.

Hope this helps, but you really need to read Harvey's thread.

The mic I built is an optical mic. Basically a light shines on the membrane and more or less is reflected off and onto a sensor, depending on the distance the membrane is from the sensor (as it moves back and forth in response to the sound waves). The sensor is a type of transistor that passes more or less current, depending upon how much light is shining on it, and this current is then further modified and sent to a preamp.

As far as I know, there is no optical mic produced as yet that is suitable for quality audio recording, but it won't be long.
 
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While I'm at it, I should give credit to those that made this project possible (so far):

Samples, though I haven't used most of them so far, from Fairchild Semiconductor, Texas Instruments, Analog Devices, National Semiconductor and Vishay.

My son gave me a bunch of old circuit boards to scarf parts off of.

My daughter B encouraged me to go on when discouraged.

My wife hasn't divorced me (yet). :)
 
Thanks for the speedy responses guys, I really appreiciate it. I managed to find a dynamic capsule: http://www.mouser.com/index.cfm?han...uctid=244803&e_categoryid=401&e_pcodeid=02502 so I think I'm going to give that harmonica mic a try for my first project. After that maybe I'll try to make a decent SDC stereo pair with those condenser elements you mentioned. I can't wait until the parts arrive! Even if they don't work, it'll be a lot of fun building them, and I'm sure I'll learn a lot.
 
crazydoc said:
Go to the first two threads in the mic forum (the stickies) - they will explain it all.

Here's a quick and dirty
http://www.modernrecording.com/articles/soundav/link19.html

In a nutshell:
A condenser mic uses a membrane or diaphragm as a part of a capacitor - as the sound waves move the membrane farther from and closer to the backplate, the capacitance changes correspondingly, and the rest of the mic circuitry changes this into a useable electrical signal to send to the preamp.

A dynamic mic uses a coil of wire attached to a membrane. This coil is suspended in a magnetic field, and when sound waves move it in this field a corresponding current is produced, which is then sent to a preamp.

Hope this helps, but you really need to read Harvey's thread.

The mic I built is an optical mic. Basically a light shines on the membrane and more or less is reflected off and onto a sensor, depending on the distance the membrane is from the sensor (as it moves back and forth in response to the sound waves). The sensor is a type of transistor that passes more or less current, depending upon how much light is shining on it, and this current is then further modified and sent to a preamp.

As far as I know, there is no optical mic produced as yet that is suitable for quality audio recording, but it won't be long.
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Thanx Doc!
 
Mylar for microphones

Hi - this microphone sounds very similar to one I was tinkering with many years ago (about 1993, as I recall). I have since found a good cheap source for mylar (aluminised or plain). The place I got mine was kyte supplies outfit. They supply mylar down to 2u. I purchased 5u aluminised mylar very cheap - £5 plus postage (7.5m x .31m).
http://www.freeflightsupplies.co.uk/ look under "lightweight covering materials". You can tension it with the hairdrier method, as already posted. It's quite tough. I also experimented with it for electrostatic headphones and capacitor microphones etc., but the reflective optocoupler method gets round all the problems of capacitor mics. The optos I used were Siemens - like 3 pin transistor packages. I forget the number. After I had "invented" this mic, I was very excited until I realised that there was a similar project in the Siemens application notes that predated my idea by years!! Mind you, it took some digging to find it, and it doesn't appear anwhere on the internet - none that I can find, anyway.
 
Hey CrazyDoc, have you done anything else with the project since this thread died? It was too cool to let die....
 
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