mic preamps

[Kipper4]

Guys i'm a newbie here so go gentle.
I've been messing around building guitar effects since christmas in a bid to learn a little about electronics.
And i really love it.
I hope to move onto bigger things in time.
Anyway I'd like to see what goes into phantom power mic preamps the onboard kind.
So if anyone knows of some schematics i could look at and see whats going on inside i'd be greatful.
I want to further my learning and perhaps build some too.

 

[Rochey]

If your just coming over from fx pedals (we all did I think) try the expat audio Eden Pre. It's designed precisely for folks in your position.

 

[Kipper4]

Thanks for that. I see where your coming from and it looks like a nice unit. great price too.
Unfortunately it looks like a boxed unit where as i was looking for an onboard the microphone type of circuit and preferably not smd as i'm not yet equipped or practiced in the art yet. I'm still at the perfoard through the hole stage.
Maybe i have a ways to go yet.
i appreciate the help.

 

[zebra50]

i was looking for an onboard the microphone type of circuit ...

What exactly are you trying to do with this? It isn't really clear from your post.

Are you building a condenser microphone and looking for a microphone circuit that requires +48V, to work with a capsule that you have? That is what it sounds like you are looking for.

Or are you looking for a mic preamp that supplies +48V and will sit between your existing microphones and a recording device? This is what most people would call the preamp.

Stewart

 

[Kipper4]

Hi Stewart it's Kip4 from HR
I'm looking for a microphone circuit that requires 48v phantom power or more to the point shcematics for them so I can have a look and see what's involved. And maybe make a board from one and buy a capsule later. At this point I want to understand the circuits
Study the different  sorts of circuits involved in the inside of mics.
Learn also about mic transformers but that's a different thread.
Thanks for the help and replies guys I appreciate the help and I'm sorry I didn't make my self clearer before.

 

[pasarski]

http://www.sdiy.org/oid/mics.html

You could start with Oktava circuits or the Neumann KM83/84/85.

 

[HellfireStudios]

From what I gather, you're looking for mics that do not require their own power supplies (like tube mics) to run. In that case, the U-87 clone kit is a phantom powered mic. As is the Schoeps circuit that is in a lot of Chinese mics. The former being transformer-coupled will increase the build cost, but the sound is really nice.

-James-

 

[zebra50]

Hi Kip,

Good to see you over here - you have certainly come to the right place.

Here are a few phantom powered mic circuits to get your brain juices flowing.

http://www.xaudia.com/omnip/Mics/MicSchLib/MXL603S.jpg
http://www.xaudia.com/omnip/Mics/MicSchLib/NeumannKm8345sch.jpg
http://www.xaudia.com/omnip/Mics/MicSchLib/NeumannU87asch.jpg
http://www.xaudia.com/omnip/Mics/MicSchLib/OktavaMK219.jpg
http://www.xaudia.com/omnip/Mics/MicSchLib/Schoeps.pdf
http://www.xaudia.com/omnip/Mics/MicSchLib/SonyC38Bschem.jpg
http://www.xaudia.com/omnip/Mics/MicSchLib/mxl2001.gif

I'm not explicitly recommending any or all for DIY, but they should keep you out of trouble for a while. For DIY, Hellfire's suggestions are not bad. Or start with the KM84, which is a good general purpose circuit and  not too hard to follow.

Stewart

 

[Kipper4]

Great stuff guys.
The transistors are a little differant to my stock items so far.
Intresting circuits i must investigate them more
Thanks

 

[Kipper4]

Anybody got a schematic for something simple that i could make a shotgun cartridge mic out of.
I have the cartridges i was thinking one of those Panasonic capsules that are all over ebay.
bear in mind i havent yet got round to smd. I'm getting a rework and new solder station this month hopefully.
If the kids give me some money for fathers day. They better had I'm THAT good to them.
anyway thanks

 

[HellfireStudios]

This should fit the bill.

http://recordinghacks.com/articles/how-to-build-a-microphone/

-James-

 

[gyraf]

shotgun mics are hard - the directionality is most often built into the capsule mechanics

Jakob E.

 

[strangeandbouncy]

Hi Jakob,


    I think he means something like this


http://www.12gaugemicrophones.com/red12.html


  . . . an omni electret built into a real shotgun cartridge!



      ANdyP

 

[gyraf]

;D aah - makes much more sense now....

 

[Kipper4]

Thanks again guys. just what i was looking for.

 

[Blue Jinn]

Hey,

Sorry late to the thread.  I'm a novice here,  so take what I say with a grain of salt. But the Schoeps circuit is pretty common, and if you look at the schematic, the power part of it distinguishable from the mic amplifier part of it. It's not electret though. Also, RuuDNL has boards for this. They aren't labeled so you need to find internal pictures of one to mark out the components, but they are fairly inexpensive an dshipping from Holland to England might be cheaper.

Also, Naiant aka Mshilarious; has an electret circuit using a 6418 tube. It's phantom powered and has a pretty low part count if you want something different.

 

[Kipper4]

Thanks Jinn both of those sound intresting. Do you have some links please.