Neumann U47FET Clone: D-U47 FET Microphone Project PCB Build thread

[poctop]

Interrested in 2 of them...

And as you asked me, european poeple can post their need in D-U47Fet styroflex sets there :
http://www.groupdiy.com/index.php?topic=49926.0
I will certainly organize something for those caps.

Thanks LoLo-M,  this is very appreciated ,
The Bom is ready and should be posted very very soon,
DAn,

 

[Scrappersa]

I'm in for one as well!

 

[berkleystudios]

interested in a pair, lets see if my wallet is though haha

 

[Jim50hertz]

1 for me please Dany 

 

[signalflow]

2 depending on price.

-Casey

 

[Dylan W]

I've heard that the original U 47 FET was cardioid-only because they used capsules that were out-of-spec on the rear. Is there any reason why, with a fully functional dual diaphragm K47, you couldn't add a simple switch for omni?

 

[EvLoutonian]

I'm keen.

 

[tonycamp]

oh...ok, twist my arm, i'm in for 1 also

 

[Govinda Doyle]

I'm keen for 1!

 

[Steph.B]

Interested in a pair please !

 

[tomas1808]

Any news on the transformers?

 

[poctop]

Currenlty in Validation in the Lab,  just making sure everything is perfect before i go ahead and release,
So Far very Good is what i can say ,  i am also in discussion with Brian Sower for the transfo but as initially the Transfo is 9:1 and it has a very nice sized core and the bass response out of the mic is very impressive ,

Keep you posted very very soon ,

cheers,  ;D
Dan,

 

[poctop]

This is how it Happened  ;D
D.

Microphone output 

 

[poctop]

Since the Experiment did all go well , i have some pcb for any D-U47FET enthousiast outhere
see the WM,
Dan, 

 

[tomas1808]

Poctop awesome work!

BTW, are you sure this will fit the red MXL 550?

 

[poctop]

Poctop awesome work!

BTW, are you sure this will fit the red MXL 550?

At this point No confirmation, i did not have one i hand but the pcb is 44mm width and not very long,
I posted all the dimension of the pcbs in the thread as of now this might help, I ended using it in the U67 body to test but the final destination will be in a gt-2B from Chunger ,  The original Version wich is all tantalum in for polarized caps  is  the default BOM and it is also a bit lower profile than the electrolytics Verison.
Hope this helps,

 

[poctop]

http://cinemag.biz/mic_output/CM-20110.pdf

This looks like a very nice Chunk of metal to fit this project Needs,

Just a toughts  ;D

D

 

[Winetree]

Looks like Cinemag offers 2 versions of the output transformer.
100% High Nickel or 50/50 Nickel Steel
Which one?

 

[Steph.B]

Hi folks,

I've re-read the thread and came aware that Sowter will propose a new transformer for this project (type 1303).

I've just mailed them to have some news about it.

Cheers,
Stephane.

 

[poctop]

Here is the asnswer I got from Brian Sowter ,

1303 (U47 FET).  Ratio 9:1  Impedance ratio 16200/200 Ohms.

1304 (U67).  Ratio 7:1 Impedance ratio 9800/200 Ohms.  Feedback winding 22:1

Both cores are 100% Mumetal.  Expected LF cut off frequency less than 10 Hz for both transformers.
Total Harmonic Distortion better than 0.05% at 50Hz.


I am just not sure about the core size ,  he is expecting some spec sheets soon , will keep ya posted ,

Dany,


Other info from B.Sowter,

I have released these transformers to the works and Ruth will be in contact with a quote.
Type 1303 U47FET
Type 1304 U67
Both will be in 34 mm dia x 24 high cans.


I am sure there is a possibility to have them outside the can if you ask for it ,
this is gonna be fun ,
Dan,