[Canakas]

I'm looking for a good preamp for a Röde large diaphragm condenser mic.

I hear good things about the AD 797 and the LT 1028 opamps for this application. Anyone like to shed a little light on this matter?

I'll pay decent money. Send me a PM if interested.

 

[rickcr42]

If you are adventurous and want to take a crack at this yourself i can provide links to some serios mic preamp plans.Where the cost ramps up will be in the very critical input transformer choice but the rest is easy.you could even do a two box design with box-A the dedicated Mic pre and Box-B the bias supply.This would make the design more of a universal mic stage and with a proper input pad stage and even a variable high end rolloff filter a good basic studio mic stage useful for both dynamic and electret elements.

The "large diaphragm" part.Is this to be a kick drum mic stage ?
If so the design also needs to be a high input overload one or have a compression section added as a safety valve.

 

[Canakas]

Thanks for the reply. Its very nice of you to offer links.

yeah, I might be interested in doing it myself. Though it may well be far over my head as im quite green to electronics. I think im going to hold out a little longer, to see if someone is seriously interested. Maybe I should put in one of them builder needed threads...?

I use the mics (Röde, Neuman & the likes) for vocal recording =)
so luckily no compression needed I think.

-canakas

 

[camaronkazi]

I would be interested in those links if you wouldn't mind posting them.
Thanks in advance.

 

[ble0t]

Some of the guys over at diyaudio already put something together...here's a link...

http://www.vikash.info/audio/pim/micpre.asp

 

[Canakas]

Thanks for the link ble0t !

I guess i'm looking at doing the work myself =)
It'll be what they call a learning experience.... oooo

-snaaack

 

[rickcr42]

posted in wrong window

 

[rickcr42]

OK.vocal mics.

You realise that are a mic stage for voacl use is rarely of the "flat" or nuetral type but are more chosen for the very colorations they instill in vocacls ?

Basically are a "special effect" that are chosen for the very tone they impart ot the vocalists "sound" and this is more often than not the input transformer tone that determines the end sound.
A "clean" mic stage would use a Jensen and slightly "romantic" (though still clean,just harmonically different) would use maybe a Lundahl.

then there are the choices between an IC gain stage,s discrete gain stage and a tube gain stage so choices are many.
Not trying to discourage just let you know there are options.

for a good selection of schematics check out the Jensen Transformer library.These are all sound designs :

http://www.jensen-transformers.com/apps_sc.html

another more complete IC based design is here with a pcb layout :

http://www7.taosnet.com/f10/ssmicpre.html

notice it is described as a "transformerless SS Design" and links to this

http://www.iso-max.com/as/as016.pdf

to "finish" the design by adding the front end.
The Phantom powering,the input padding,the polarity inversion and the hi/lo Z selection which makes it a complete design useable in the studio.This could also be added to another chosen design as the front end.

a very tidy and CHEAP kit is here :

http://www.paia.com/phantom.htm

though would need to have upgraded parts (opamps) for pro use in the studio though it really is a nice preamp as is and when price considered,no contest.
This mic stage could also be run from a lead acid battery supply for location recording.

one I like a lot is this guy here in either the tube or SS versions.Fully engineered and realised,this is no toy but a true top quality mic stage :

http://www.hamptone.com/

http://www.mojopie.com/hjfp2.html


and this :

http://www7.taosnet.com/f10/micpre.html

again not a full kit but a finished design with boards designed.The gerbers can be made into a pcb by any borad hose though Point-to-Point wiring is fine also.


and finally right off the AD797 and the LT1028 data sheets (download from the corporate sites) you will find usuable designs.

an "article of interest" :

http://www.uneeda-audio.com/phantom/index.htm

hope this helps a bit

rickmonster

 

[Canakas]

Great links rickcr42, and thanks for lending competence,
this will all be interesting reading.
Ill post back soon as I read all, so we can talk a niveau.

até

-canakas