While my advice varies from the rest, nothing I say is intended to contradict what the others say.
I suggest reading as many articles and other resources as possible before spending your hard earned brass on any parts. There are many types of microphones, made from different components, designed to accomplish a myriad of tasks. Learn all you can about microphones before building one. Do a broad web search and read as many articles you can. Mr. Jules Rykenbush has published several online articles describing his work, and he links to several other sources. Do the homework, and build what you really want later.
I am a long time radio enthusiast and have built all sorts of radio and audio accessory kits over the past 40 years. Nevertheless, I actually learned very little from building kits. The instructions merely say where to place parts on the circuit board - they rarely explain what each part does along they way. While a few instruction guides provide a general explanation of the kit's theory of operation, they rarely explain what each component does. Moreover, kits are usually more expensive than buying parts separately - after all the kit seller has to make money.
While I appreciate you want to get going right away, I assure you this is the best approach. You will know what you want, and why, and you will only buy parts that suit your objective. I intend no offense or criticism of any other comment. I merely suggest you will learn more, and end up with a better, more appropriate result this way.
You did not really answer Mr. Elsmurph's question about your level of electronics experience. I also ask: What do you want to accomplish? Do you want a microphone for live performance or recording? What sounds do you want to capture? Will you be signing or talking or playing an instrument? What venue? Small acoustically untreated room or larger treated room or some sort of live venue - or outdoors? All of these factors affect what type of microphone you should build.
Again, I am not being critical. I am sincerely convinced you should learn about microphones first, and build something that suits the intended task latler, when you know what you need. This research will pay dividends in the long term.
Search the archived messages on this form and another called "micbuilders." Search AliExpress and eBay.com for descriptions and prices of parts. Sear the web for articles on mic building projects.
Th is is, of course, JUST MY take. You be the judge! Good luck - it is a proworthy enterprise. James - K8JHR
Have a good day thanks in advance
