Neumann Vintage U87 Clone : Build Thread.

[burglar]

Hi folks,

I can't seem to figure out the oscilloscope I borrowed of a friend.  What's the most accurate method of biasing without a scope?

B

 

[kante1603]

Personal statement:

I got hundreds of PMs during the last couple of months on how to build this mic.
And I always replied and tried to help as good as I´m able to,guided guys with zero posts(!) through it,even sent them parts,but now it becomes way too much for me.I have had more than 25 mails from one single guy here recently.

People-please ask your questions here in the thread,that´s what it is for!!!

I know sending a PM is sooooooooo easy,and no one must feel bad or ashamed.
But doing this is really unfair:Nobody else can participate or discuss it.
And I´m not your private service-engineer nor will I support some people anymore when I feel they are nothing but lazy.
This forum is about sharing experiences,discussing things,helping each other,developing stuff and so forth,but not a cheap shopping mall with a full service included.

I say it again:Read the thread,if necessary two or three times:Most issues have been covered already,I´d say about more than 90%.
Learn at least some basic electronics or do some easier things like a D.I.-box,a simple mic-preamp etc. first,learn at least ohms law,what a dmm does and how to use it,improve your soldering skills and so on.There´s tons of infos on everything here in the forum and on the web.

Rome wasn´t built in a day,we all had to go through this.

With this in mind,best regards,

Udo.

 

[poctop]

I Agree with Udo,  All questions shall be posted on the Forum has it gets all the visibility it needs and all of us that had or have experience with the project can help and assist folks ,  it is always a good thing to go trough the thread as it contains Gazillions of already answered question on many aspect of the build and such ,  I personnaly always had this principle in mind is that , help yourself and the sky will help you  ,

with this in mind ,
Best, Regards,
and happy building.
Dan,

 

[jasonallenh]

Personal statement:

I got hundreds of PMs during the last couple of months on how to build this mic.
And I always replied and tried to help as good as I´m able to,guided guys with zero posts(!) through it,even sent them parts,but now it becomes way too much for me.I have had more than 25 mails from one single guy here recently.

People-please ask your questions here in the thread,that´s what it is for!!!

I know sending a PM is sooooooooo easy,and no one must feel bad or ashamed.
But doing this is really unfair:Nobody else can participate or discuss it.
And I´m not your private service-engineer nor will I support some people anymore when I feel they are nothing but lazy.
This forum is about sharing experiences,discussing things,helping each other,developing stuff and so forth,but not a cheap shopping mall with a full service included.

I say it again:Read the thread,if necessary two or three times:Most issues have been covered already,I´d say about more than 90%.
Learn at least some basic electronics or do some easier things like a D.I.-box,a simple mic-preamp etc. first,learn at least ohms law,what a dmm does and how to use it,improve your soldering skills and so on.There´s tons of infos on everything here in the forum and on the web.

Rome wasn´t built in a day,we all had to go through this.

With this in mind,best regards,

Udo.

So now I introduce my issues to the board  ;D

I'm building the 87 using what Udo has identified as an older version of the Bhrngr B-2 Pro. The whole capsule/switch assembly is shockingly terrible and convoluted, so I started by just taking apart and gutting every last section as you can see in these pictures-

As you can see, there are tabs and pins inside with wire coming out of this plastic body section-

https://www.dropbox.com/s/00dhuld1ure98t9/IMG_20130614_175054.jpg

The top half of the capsule can be unplugged via a set of six pins, leaving you with this body section-

https://www.dropbox.com/s/9qbbnentub9rln6/IMG_20130615_170556.jpg

Now open up the top half of the capsule, and you can see the "sleek"  wiring for the capsule and switches-

https://www.dropbox.com/s/boymici39dhrjk8/IMG_20130615_171018.jpg

Then, I opened up the bottom half of the capsule assembly (the part that the top half 'plugs in' to) and found more capacitors. Why not?  :

https://www.dropbox.com/s/qongi87ygmhh8pq/IMG_20130615_172512.jpg

So, with all this nonsense addressed, I've planned to cut all the switch PCB traces (except the shielding ones!) and run them through three separate holes that I'm going to drill through several layers of plastic, marked in this picture-

https://www.dropbox.com/s/ma8f7av30wdq6ec/IMG_20130615_175207.jpg

I have a lot of thin ribbon cable that I think will work fine, and will at least be as good quality as the switch->pcb trace->male pin->female pin->wire to body PCB path that it takes now At least for now, I have a way to put the whole thing together. I'll be ordering components for the PCBs soon, I'll keep everyone updated. I intend to make this thing work!

Now I just need to find the most current BOM......

 

[poctop]

Now I just need to find the most current BOM......

I always use the same link and update the BOM as it needs to be .

Right Here, Just change the currency to wherever you are located ,
https://fr.mouser.com/ProjectManager/ProjectDetail.aspx?AccessID=c5d4de9f07

Hope this helps,

Dany,

 

[jasonallenh]

Now I just need to find the most current BOM......

I always use the same link and update the BOM as it needs to be .

Right Here, Just change the currency to wherever you are located ,
https://fr.mouser.com/ProjectManager/ProjectDetail.aspx?AccessID=c5d4de9f07

Hope this helps,

Dany,

THanks a lot Dany! Just got my Pair of PCBs from you. I don't miss etching my own... THANKS! ;D ;D

 

[kante1603]

Very cool stuff!
Another B2Pro version covered,now this is a really great contribution!
Thanks a lot for the pics showing the inards of that plastic thing,this is really helpful.
Yes,ribbon style wires will do fine,we don't have to run high current here.
Yes,keeping the switches shielded and grounded is imperative,otherwise they can pick up noise from rf or even your electrostatic body loaded when touching the actuators.Some guys here had exactly this phenomenon.
I'm quite interested on how dense this will be,the full metall versions I've built had some more room inside.

Keep us posted please,

best,

Udo

 

[jasonallenh]

I'm quite interested on how dense this will be,the full metall versions I've built had some more room inside.

I just did some measuring.... lets take it a piece at a time:

1. By folding the solder tabs against the plastic piece, I've immediately gained a couple precious millimeters. I'll probably need to cover them in heat shrink or tape to keep them from bumping into something they shouldn't.

2. The PCB will definitely fit. It's smaller than the original... by a lot. the original board is 70mm x 38mm, so Dany's tapered PCB is shorter by 15mm (without altering it at all) and at it's widest point (the top of the taper), it is only 2mm wider. You could file down more than that if you needed to, but you don't!

3. I'm not sure how tall the completed taper PCB is (maybe someone could measure that for me??) because I don't have the components to populate the board yet. however, The original board has electrolytic caps that are 19mm tall when you count the thickness of the PCB. I put the old board back on the mount and stuffed it into the body tube, and it seems like there's still plenty of space. I really don't think component height will be an issue, especially since I'm cramming the board to the top of the taper.

4. Obviously, the transformer is going to be the big challenge. With Dany's board on, it looks like I'll have about .78" from the edge of the PCB (without altering it!) to the metal ring where the XLR connector is recessed. There is almost enough inside that recess to make it 1 inch even (useable area... there's actually a little more than that but the XLR pins are in the way), which should be the exact 1" length stated on the T13's spec sheet. Even if that is not enough space to mount the transformer vertically, it appears that it would fit horizontally fairly easily.

This picture isn't much help (couldn't get the angle right), but it at least gives you an idea of what I'm working with. Can't say I'm discouraged yet! =)

 

[JessJackson]

Personal statement:

I got hundreds of PMs during the last couple of months on how to build this mic.
And I always replied and tried to help as good as I´m able to,guided guys with zero posts(!) through it,even sent them parts,but now it becomes way too much for me.I have had more than 25 mails from one single guy here recently.

People-please ask your questions here in the thread,that´s what it is for!!!

I know sending a PM is sooooooooo easy,and no one must feel bad or ashamed.
But doing this is really unfair:Nobody else can participate or discuss it.
And I´m not your private service-engineer nor will I support some people anymore when I feel they are nothing but lazy.
This forum is about sharing experiences,discussing things,helping each other,developing stuff and so forth,but not a cheap shopping mall with a full service included.

I say it again:Read the thread,if necessary two or three times:Most issues have been covered already,I´d say about more than 90%.
Learn at least some basic electronics or do some easier things like a D.I.-box,a simple mic-preamp etc. first,learn at least ohms law,what a dmm does and how to use it,improve your soldering skills and so on.There´s tons of infos on everything here in the forum and on the web.

Rome wasn´t built in a day,we all had to go through this.

With this in mind,best regards,

Udo.

With this in mind, it would work well if the forum admins could create "sub threads" a user could establish a support ticket for a problem i.e (capsule connections) and if that problem comes up with another user later down the line, they could reffer to the previous thread rather than sifting through hundreds of posts, reading everything in the hope that their problem is talked about.

car fixing forums have this kind of feature

J

 

[kante1603]

Good idea Jess,

Udo.

@jasonallenh:Can not see the pics (just a questionmark).

 

[jasonallenh]

Good idea Jess,

Udo.

@jasonallenh:Can not see the pics (just a questionmark).

Whoops!

Here-
http://db.tt/X4zubQlE

 

[kante1603]

O.k.,could work,remember not to touch the XLR pins with the transformer.

Have fun,

Udo.

 

[Garionwells]

I feel like a complete moron on here but I'm extremely new to circuitry and building. Can anyone give me a very specific and basic parts list as well as the instructions on how to build them right? I know there are specific ways to color code and find out which resistor goes where but if there is an easier way I would be eternally grateful!!

 

[kante1603]

With no basic background this is not a good project to start with,sorry.

 

[poctop]

I feel like a complete moron on here but I'm extremely new to circuitry and building. Can anyone give me a very specific and basic parts list as well as the instructions on how to build them right? I know there are specific ways to color code and find out which resistor goes where but if there is an easier way I would be eternally grateful!!

Follow the thread and refer to the pcb silk screen and basic schematic will help your journey,
BEst,
Dan,

 

[0dbfs]

RE; Instructions (my method):

Print BOM, both original and Dan's schematics plus any other docs in the docs section.

Sort your parts in baggies or dishes or something and write R1, R2, R3, C1, C2, C3, etc on the baggie....

Use a DMM to measure and confirm the part values before soldering them into the PCB. You'll need a DMM with capacitor test to test the C's and inductor-test to test the inductors. Some DMM's have an HFE test for the fet but you may want to use the methods here to further test and select the fet for better SN/R (ie; more gain) or better headroom. You may end up with more than one DMM but that's ok

Get a cheap scope on craigslist or ebay for the cal portion. It'll be useful for other projects too.

Read the whole thread before you start soldering and reference the DOCs Dan has assembled throughout the thread-review (read through a couple times). Make yourself some notes about important issues and solutions others have experienced.

Keep a checklist on a printout of the BOM and schematic of which parts have been tested, and installed. Such that if you walk-away from it for a bit you can dive back in by reviewing your notes.

If you get to the end and it's not working use the binary-subdivision method of troubleshooting. ie; test/confirm in the middle of the path where the issue has been identified to determine where the fault is then re-test in the next "middle". Repeat until fault is identified. 256 points can be tested in 8 steps this way.

No matter what don't ever give up and share your questions/answers/solutions with the group.

Take pictures of all of your steps. Sometimes you refer back to those photo's for troubleshooting.

Good luck!

Cheers,
jonathan

 

[Dvaughn]

Hey, quick question.  I've looked at all of the pictures of capsule connections and still feel slightly confused.  I think it's all of the front/back backplate wording.  Can someone just confirm.

The diaphragm connections go to FD and RD (FD being the one closest to the front of the mic ), and then here is where i'm confused.  Is the "front backplate" the body surrounding FD and the "back backplate" the body surrounding RD? If so this is how I connected them.

I got eric's capsule and chunger's mic body, and had to drill an extra hole in the mount to get two screws in there.  One screw on the mount is going into the front backplate with a crossing ring and is connected to FBK on the board, the other screw on the mount is just going into the back backplate with no ring just to hold it.  Then I have another screw with a crossing ring connecting to the back backplate (not through the mount) and this wire is connecting to RBK on the board.  This screw is higher on the capsule then I see in others pictures, but based on all the diagrams this seemed like the only way to satisfy everything. 

sorry for the confusing post hope someone can just quickly point me in the right direction.  Thanks

Dylan

 

[wave]

Dylan,
It sounds like you connected the capsule correctly. Maybe post a couple pics and we can tell you for sure.

Dave

 

[burglar]

Hi Folks,

Ok so I'm a step closer to biasing my mic and my BeesNeez k8 has arrived (very nice).

The problem I'm having now is that my cheap signal generator doesn't appear to have enough output to begin clipping so I am unable to move forward.  Can anyone recommend a cheap generator that will work.  Has anyone had any luck using a computer to generate the tone?

 

[HellfireStudios]

I used an iPad, an Alesis I/O Dock, and a special cable (1/4" to gator clips unbalanced) I made to get the sine wave. The app wasn't cheap (Faberacoustical Signal Scope Pro), but because this works, the computer idea should work, as well. I would think that special cable would still be needed.

-James-