Tube Mic Preamp

[yalesmith]

I am looking for a layout of a tube mic preamp build. I need it to power an SM57 microphone I want to use for recording. Any links or suggestion will be greatly appreaciated.

Thanks

[ToneMerc]

You should google "tube mics schematics", there's lot's of hits so pick your poison.

http://www.gyraf.dk/gy_pd/g7/gic.htm

TM

[yalesmith]

i am looking for the preamp, i have the the mic, just need something to power the mic for recordings.

Thanks

[Cliff Schecht]

Are you trying to apply 48V phantom power to a dynamic mic? This isn't necessary with a dynamic like the SM57..

If you need to amplify it there are lots of schematics online. Not to sound like a salesman but the PAiA Tube Mic Pre is an inexpensive kit that, with a few mods, will hold its own against much more expensive units. Even if you don't buy one, here is a schematic: http://www.paia.com/prodimages/fantusch.gif (you can find a higher resolution version on the PAiA talk forums).

[Gibsonman63]

You may want to find one that will supply switchable 48vdc phantom power or at least pass through power from your board. If you decide to use a condenser microphone later you will need it to power the mic. I was hoping to get around to building one, one of these days but it hasn't happened yet.

[Kagliostro]

May be you are interested to read this

http://www.el34world.com/Forum/index.php?topic=10116.0

Kagliostro

[Reeltarded]

RCA handbook: how to use a vacuum tube

I can't find it on Google right now. It is the basis for the best 3 tube microphone amplifiers ever made.

[Kagliostro]

And this

http://www.gyraf.dk/gy_pd/g9/g9pd.htm

Kagliostro

[yalesmith]

I have an m-audio fast track pro which has a built in pre-amp but it is not powerful enough to amplify the mic to aceptable levels . It appears to be known issue with these interface/preamps. I believe the pre-amp produces Pre-amp Gain of >40dB

[crbowman]

Just got done building a REDD.47 clone. This is supposedly a clone of the tube mic pre found in the recording desk (REDD.51) in use in EMI/Abbey Road studio 2 from January 1964 up until the late 60's.

http://blog.beatletracksband.com/2009/0 ... desks.aspx

I just got done using mine extensively on a project and absolutely love it.
Google REDD 47. Lots of info out there.

If you want phantom power, perfectly serviceable stand-alone modules can be had for around $20.00.

[yalesmith]

What would be cool is a Bill of Materials, I could not find anything online.

[crbowman]

Here ya go.
It's not entirely complete, but pretty close.
The transformers are of course the most crucial piece of the puzzle.
Cinemag can wind these for you.
Be aware, I had trouble with the Allied power tranny but that may have been my fault. Wound up using an old Schumacher I pulled out of an old Thomas organ amp.

[Kagliostro]

Sorry for the inrush on this tread with a personal question

I retrieved 2 of this transformers

can I use it for a mic preamplifier like that in the posted schematic ?

(I'm a novice about preamp input & output transformers)

Thanks

Kagliostro

[crbowman]

Sorry for the inrush on this tread with a personal question

I retrieved 2 of this transformers

can I use it for a mic preamplifier like that in the posted schematic ?

(I'm a novice about input & preamp output transformers)

Thanks

Kagliostro

The transformers for this circuit are supposed to be 7:1 and 1:7, not sure what the spec is on that one. (I'm not the most knowledgeable on transformers either)
I can say that the reviews I've read from people who tried different transformers were not positive. Doesn't mean that it won't work though.
Maybe someone else knows ???