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

[deveng]

Now have the first 2 tracks of drums using RE-20 inside kick and the U47-FET outside.  Its about 1 foot off the head and off center and it sounds very good.  I have to say, Skylar's (Equinox) Q47D capsule works quite well with this mic.  When I bought his MK47 kit, spare Equinox body and misc parts he tossed in the capsule as part of the deal.  I was blown away by his generosity.  Just want him to know that the capsule has found a good home and will get plenty use.

I'm very pleased with Dan's pcb kit. 

I've had the DIY disease for many years (building mostly discrete preamps) but my affliction has spread to input transducers!

Regards,
Jeff

 

[Biasrocks]

My preferred combination on Kick drums as well.

The FET brings so much to the party.

Mark

Now have the first 2 tracks of drums using RE-20 inside kick and the U47-FET outside.  Its about 1 foot off the head and off center and it sounds very good.
Regards,
Jeff

 

[nielsk]

About to undertake a build, and today the search engine no worky...
Can someone save me searching every page and point me to a regular BOM (NOT a shopping cart) that covers everything and explains what the deal is with the Styro caps as it looks like it is all Wimas?

 

[Zjcc56]

So I've built one of theses with the alctron GT-2B body and its killer!
the only problem is that the shock mount is nice but it makes it hard to get in to some places with the mic, does anyone know of just a screw on mount for this body? (non Shock Mount)

 

[andybaker28]

Finally Received a Short U47 FET Prototype Body From Oliver At AMI ,

i have sent the mic to higher authorities to get it evaluated, So Far So Good,

I should hear back soon,

Best,
DAn,

Hi Dan,

I just assembled the round pcb version of the Fet 47 that got from you last week. I am not getting any output as of yet, so just starting to trouble shoot. I wanted to ask a couple of things. I am using a 9.5/1 transformer that I got from 3U audio, and I have it connected red-1 brown-2 orange-3 and yellow-4.  I am not sure if this is correct. I have attached a schematic I was sent from them. The other question is that I noticed the jumpers are this version in the photo, it is my understanding that without these on the mic is without any pad and or low cut. Is that correct?

I will double check all the connections and voltages next! It was a fun build and I am excited to get this one sorted out.

here is a link to the transformer on ebay..

http://www.ebay.com/itm/3U-Audio-GZT-87-Output-Transformer-for-Condenser-Microphone-/111683319855?hash=item1a00d8382f:g:f6kAAOSwiCRUg89Z

thanks much!


Oliver Archut U47Fet Short Body Prototype

 

[poctop]

Finally Received a Short U47 FET Prototype Body From Oliver At AMI ,

i have sent the mic to higher authorities to get it evaluated, So Far So Good,

I should hear back soon,

Best,
DAn,

Hi Dan,

I just assembled the round pcb version of the Fet 47 that got from you last week. I am not getting any output as of yet, so just starting to trouble shoot. I wanted to ask a couple of things. I am using a 9.5/1 transformer that I got from 3U audio, and I have it connected red-1 brown-2 orange-3 and yellow-4.  I am not sure if this is correct. I have attached a schematic I was sent from them.

this is correct 

connected red-1 brown-2 orange-3 and yellow-4.

The other question is that I noticed the jumpers are this version in the photo, it is my understanding that without these on the mic is without any pad and or low cut. Is that correct?

Correct
Make sure you have the backplate of the capsule connected to the pad where it says bck this is pad is gnd , so your backaplte should be grounded to mic chassis , if this is not the case you will have this issue,


I will double check all the connections and voltages next! It was a fun build and I am excited to get this one sorted out.

here is a link to the transformer on ebay..

http://www.ebay.com/itm/3U-Audio-GZT-87-Output-Transformer-for-Condenser-Microphone-/111683319855?hash=item1a00d8382f:g:f6kAAOSwiCRUg89Z

thanks much!


Oliver Archut U47Fet Short Body Prototype

 

[Haberdasher]

Hello everyone, I'm here to report another success story.  This was my first diy mic, and I think I picked a great one.  I'm very happy to say it fired right up on the first try, and is very quiet.  We put it up against my sister's "good" mic and it blew it out of the water, so she is pretty excited.

I used the GT-2B body and a 47 type capsule from aliexpress, which sounds really good to me.  Cinemag 13101 for the xformer.

I thought it might be helpful if I posted some notes I made while I was building.

- The GT-2B body doesn't come with screws for the pcb's.  These were perfect.  No affiliation.
http://www.ebay.com/itm/111607847719?_trksid=p2057872.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT

- You don't need the screws or L-shape brackets on the Mouser BOM if you are using the square pcb's.

- If you are going to use the 30M resistor for R5, you really only need to order 1x 68M, not 3.

- The hole in the pcb is too small for the binding post on the Mouser BOM.  It would be better to dry fit that & drill it out a tad if necessary before population, because it's more difficult after there are components everywhere.

Thanks for the awesome project, it was a blast.  Now I kinda want to build another mic, haha. Too bad I'm broke! 

 

[micaddict]

Congrats!

Build your next with an edge terminated capsule (CK12 type). That would be a great complement. 
And are you ready for tubes?

But for now, enjoy!

 

[Haberdasher]

Congrats!

Build your next with an edge terminated capsule (CK12 type). That would be a great complement. 
And are you ready for tubes?

But for now, enjoy!

Thanks!

Yes, I'd love to do something with a tube and a edge termed capsule but that's more of a long term project, I'm afraid.

A D87 is up next, because I have everything but the tapered circuit boards and the capsule.  ;D

 

[micaddict]

Nice one, too.
Come to think of it, it doesn't really matter which one is next.
In the end you'll want them all anyway. 
Just take your time and work your way through all the D-models.  8)

Oh, and don't forget to use them!  ;D

 

[nielsk]

Finished some builds using Vintage Microphones D7 capsules, sounding great!
No problems at all, everything works perfect upon first fire up.
I did a few things that worked out well for me, first the transformer mount for the Cenimag:
I took a bit of plastic drywall J-bead, cut it to fit and bent in some sides, put some neoprene in to cushion and used tiny self tapping screws to secure it using the existing holes in the rails

 

[nielsk]

pic #2

 

[nielsk]

I also used micro-mini toggle switches right on the PCB for the PAD and FILTER, as I rarely use these on this mic it is no problem to remove the cover to switch them, works great:

 

[crackerjack555]

Vinylwall,

I see you used an Advanced Audio Ak47 capsule with your one of your mics.  Did you like it?  I'm shopping for a 47 capsule right now and preparing to start the D-47 project from http://www.vintagemicrophonepcbkit.com/D-47.html .  Seems like the AK47 price is very reasonable. 

 

[vinylwall]

Vinylwall,

I see you used an Advanced Audio Ak47 capsule with your one of your mics.  Did you like it?  I'm shopping for a 47 capsule right now and preparing to start the D-47 project from http://www.vintagemicrophonepcbkit.com/D-47.html .  Seems like the AK47 price is very reasonable.

I haven't been able to hear a noticeable difference between the Advanced Audio and Microphone Parts 47 capsules.  Both work equally good.  I have been using my U47fet builds almost exclusively on guitar cabinets.

FYI: here is something I posted a while back regarding some of the microphone builds I've done: http://groupdiy.com/index.php?topic=60417.msg766068#msg766068

 

[crackerjack555]

Vinylwall,

I see you used an Advanced Audio Ak47 capsule with your one of your mics.  Did you like it?  I'm shopping for a 47 capsule right now and preparing to start the D-47 project from http://www.vintagemicrophonepcbkit.com/D-47.html .  Seems like the AK47 price is very reasonable.

I haven't been able to hear a noticeable difference between the Advanced Audio and Microphone Parts 47 capsules.  Both work equally good.  I have been using my U47fet builds almost exclusively on guitar cabinets.

FYI: here is something I posted a while back regarding some of the microphone builds I've done: http://groupdiy.com/index.php?topic=60417.msg766068#msg766068

That's great news because I just finished my first mic kit from microphone-parts.  It's the T-12 kit with Rk12 capsule and I LOVE it. Sounds better on vocals than our TLM103! I figure if a fet mic sounds THAT good, I have to try a tube mic (U47 clone of course!).

I read your post and I am very impressed with your collection and building experience.  I see one of your builds was the D-47 that I want to build.  How do you like your D-47?  I saw it in your list, but you didn't mention it after that.

Thanks,

Troy
Auburn Hills, Michigan

 

[vinylwall]

Vinylwall,

I see you used an Advanced Audio Ak47 capsule with your one of your mics.  Did you like it?  I'm shopping for a 47 capsule right now and preparing to start the D-47 project from http://www.vintagemicrophonepcbkit.com/D-47.html .  Seems like the AK47 price is very reasonable.

I haven't been able to hear a noticeable difference between the Advanced Audio and Microphone Parts 47 capsules.  Both work equally good.  I have been using my U47fet builds almost exclusively on guitar cabinets.

FYI: here is something I posted a while back regarding some of the microphone builds I've done: http://groupdiy.com/index.php?topic=60417.msg766068#msg766068

That's great news because I just finished my first mic kit from microphone-parts.  It's the T-12 kit with Rk12 capsule and I LOVE it. Sounds better on vocals than our TLM103! I figure if a fet mic sounds THAT good, I have to try a tube mic (U47 clone of course!).

I read your post and I am very impressed with your collection and building experience.  I see one of your builds was the D-47 that I want to build.  How do you like your D-47?  I saw it in your list, but you didn't mention it after that.

Thanks,

Troy
Auburn Hills, Michigan

I have a couple of the D-47 builds now.  I have been trying out one of them and like how it sounds on acoustic guitar.  Haven't recorded much else with it yet.

Here are some photos of one of the builds:  http://groupdiy.com/index.php?topic=58609.msg769203#msg769203

 

[crackerjack555]

Very cool! Can't wait

 

[skidmorebay]

Dan, or anybody,
Any ideas what I might be dealing with here? My D-U47FET has worked fine for a few years. But now it has low output and is noisy.
Checking voltages, I get good readings at T7 and T5, and phantom power is 47V at XLR pins 2 and 3.
But, at T3 I get 43V at the collector, but only 29.5V at the Base (and positive side of C6), and I get 38V at the emitter.
I only get 21V at the positive side of C5. Other values in that area of the circuit are also incorrect.

I replaced T3 with a new one, but it didn't help.

Any ideas on where to look next?
Thanks,
JS

 

[skidmorebay]

Solved my problem - broken wire between the two PCB's (A to AA) . Back in business.
JS