I-Mic Harmonica Microphone




This is how to build a simple harp mic that was based on the imic design. I ran into elsewhere on the web but did not see it here and thought it would be a good fit. It is easy and cheap to build and provides a chance to get really creative by choosing a cool enclosure. If you don't play harmonica don't or play it as badly as I do it still has other uses. It is a dynamic mic and can be used as any dynamic mic would be used. The design really lends it self to being plug into to guitar type amplifier that is why harp players dig it. If you are a guitarist you can plug it into your amp and effects and get some nice dirty vocal or use it as a feedback instrument if you dig noise.

Step 1: Materials & Tools

Bill of Materials:

Electronics Grade Solder

Wire (i used 22 gauge braided but anything will do only need acouple of feet and 2 colors are nice to keep track of which wire is which)

10k potentiometer (use can use other values if you wish but this works good here is a link to the i used from mouser. small is good cause of little room 16mm pots work great.)

Knob for pot

1/4" phono mono jack (i used switchcraft #11there a quality but any jack will do and you can 1/8" if you wish)

Dynamic Mic Element ( I used a Kobetone 25LM032 but other can be used. The are lots of nice element available on ebay and surplus and antique electronic suppliers on the web. Or you can canabilize something you have around)

Enclosure (This is the fun part. A lot of people building these have chosen plastic bottles but any thing the right size, a little bit durable and able to be tooled will work. I use an empty lotion container from my wife because it was what I had around. TO get the idea going here is a link to someHere! Here!)


Soldering Iron (15W to 35W you have to be carefully with higher wattage irons on the element)

"Drill & Bits"

Wire Cutters

Wire Strippers

Maybes?depending on enclosure choice




Bubble wrap


Step 2: Wiring

1. Forgive my art skills.

2. Before anything else line everything up to make sure things fit and find out where everything goes.

3. Cut wires to right lengths and strip ends.

4. Solder together according to diagram. Use caution soldering the element to much heat can ruin them. The "-" connection is usaully on the left when face away from you. It sometimes is the only one marked and might only be marker with a black line or dot if there are no positive or negative markings.

5. Double check wiring.

Step 3: Construction

1. Drill holes to mount components.

2. Prepare space for element if necessary.

3. If the enclosure is solid holes will have to be drilled to allow air to hit the diaphram of the mic. Or a large hole can be cut and covered with a protective mesh or screen or screens. The mesh from a kitchen or tea strainer would work. If the enclosure is open on the element end it will need to be capped off to protect the mic.

3. Mount jack & pot.

4. Mount Element. It needs to be secure so if the cavity is larger than element it will need to be held in place. It can be encase in a styrofoam piece the fits tight in the enclosure or use bubble wrap etc. ALso it can be glued, epoxied, taped, etc.

5. Close everything up and make sure all is well.

Step 4: Finish

Plug in and blow that harp!

You can see some of my other creations http://kubton.com/diy.html



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    17 Discussions


    11 years ago on Introduction

    Great instructable, but I have a question: would the original microphone element from an old phone work? Thanks.

    2 replies

    Reply 11 years ago on Introduction

    I am not sure if the carbon mics in old phone s would work or sound good but they might some old mics had similar elements. You might want to check this out also:

    telephone mic


    Reply 4 years ago on Introduction

    The carbon element is NOT a good match for a harp mic. A: they require the equivalent of phantom power (about 48V) to get active signal through it. This power was provided by way of the telephone lines back in the day, and no guitar amp will provide that unless you use some kind of preamp in front of it that is phantom equipped. B: They'll feedback like crazy with all that voltage gain!

    The earpiece element is the thing to use. It basically winds up being like a dynamic element.


    7 years ago on Introduction

    Check out mine i just made with a fence post cap (not the round one) a pvc end cap and some bits and pieces i had laying around. i think i just might paint the pvc white part but leave the steel.

    Great sound i used a mic element from an old cheap $50 mic that didnt work anymore.


    Bullet mic.jpg
    denanderenClayton H.

    Reply 9 years ago on Introduction

    though i haven't tried it myself, i believe you could use this diagram for about any element you want.


    10 years ago on Introduction

    hay thank's a lot man that realy helped thanks agen grillslinger!!!!!!!!!! p.s you rock man!!!!!!!!!!!


    10 years ago on Introduction

    hay grillslinger how did you make a mic out of an led flashlighjt????

    1 reply

    Reply 10 years ago on Introduction

    Not quite as exciting as it seems. Make sure you find the right flashlight. A search in Amazon.com fro "titan led flashlight" brought up a lot of good candidates. Find out that turns on with a rubber button on the end opposite the light. Then all I did was transfer the guts from a small microphone from a little kareoke machine, chord and all. I will say this though...the quality of sound is probably not as good as the microphone on this instructable. I-mics have a pretty good rating.


    10 years ago on Step 3

    what typ of lotion bottle did you use?????


    nice man, real nice, i find it helps cut feedback if you shield teh inside with tinfoil, just a tip, nice work man.


    11 years ago on Introduction

    That is great looking. Using the old phone headset just perfect.