DIY microphone project

I had some microphone capsules laying around, so I thought it was a good idea to use them.
After some sawing and filing, this is the result:



The microphone is based on a K47 style capsule:



The electronics are based on a Schoeps style circuit, with a DC/DC converter to produce a polarisation voltage of 60 volts.



By the way: the body of the microphone was made of a piece of aluminium tube from a laundry drying mill. Well, it was too high anyway!...

Nice work! Can you tell more about the DC-DC converter part, a schematic maybe? Did you try the mic without it?

Nice to see some "from scratch" DIY in the mic section. Looks great.

pasarski said:

Can you tell more about the DC-DC converter part, a schematic maybe?

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The schematic is basically this circuit:



I raised the value of the zener diode to 7.5 V.
Also I used a trimmer instead of the 8.2 pF capacitor, to 'fine tune' the output voltage.
Of course the microphone works without this converter, but a higher polarisation voltage means more output and a better signal to noise ratio. (Lower self noise.)

Nice looking mic! To me the capsule looks like 32mm K87 style.

Best, M

nice looking project.
have you done any tests vs some projects offered here?

I love the final result body.

Great job - nice to see something that isn't a kit. Did you etch the PCB?

LOL Wait then till you see my home brewed c12... Home everything.

zebra50 said:

Great job - nice to see something that isn't a kit. Did you etch the PCB?

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dito. I like when people try something new. As convenient as the various kit projects are for beginners, I'd like to see more "real" DIY-stuff.

I like your DIY mic body - looks really handsome! 

I have to agree with Marik, the capsule doesn't look K47-style to me. The hole pattern is K67-style.

zebra50 said:

Did you etch the PCB?

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Yes, it was DIY from the beginning until the end!

3nity said:

LOL Wait then till you see my home brewed c12... Home everything.

Click to expand...

I can't wait to see it!

Rossi said:

... the capsule doesn't look K47-style to me. The hole pattern is K67-style.

Click to expand...

To be honest: the capsule on the picture is a different one than the one that is in the microphone now. I thought it was a waste to use a double sided capsule when I only wanted a cardioid pattern. It is a K47 now.
(This prooves again that you never can fool real professionals!)