Neumann Vintage U87 Clone : Build Thread.

[micaddict]

I have read a few comments that this build has low output/sensitivity.

More headroom than the U87Ai, though.

 

[bnwitt]

Ok that makes sense.  I guess I'll just have to increase the preamp gain over more modern mics in my collection.  Do those of you who have been recording with this mike like It a little or a lot?

 

[bnwitt]

Is there a schematic on the D87 which can be compared to the U87i?

 

[micaddict]

Is there a schematic on the D87 which can be compared to the U87i?

Dany's website states his is the "U87a", but I think that's a typo.
Or maybe he means the very first version?
In any case it's not the Ai.

http://www.vintagemicrophonepcbkit.com/DU87.html

 

[bnwitt]

Micaddict,
Thanks for the reply.  I know it's not the "ai" version but rather some version of the "i" hence the lower output.  I'm just curious as to how accurate the D87 circuit is compared to the original version from which it was taken.  I'm looking at the BOM and seeing things like a 24V zener rather than the 33V shown on the "i" schematic so I was hoping I could get a schematic for the D87 which would make id-ing the differences easier.

 

[bnwitt]

So no schematic I guess

 

[poctop]

So no schematic I guess

yes the Vintage Version is 10db lower output than the modern AI version ,
this project has nothing to do with the U87Ai,

Yes there is on the very first page ,
B1 Reference Voltage and Schematic https://cdn.groupbuilder.com/groupdiy/u/39511/58d1402a08c0a.pdf

B2 Reference Voltage and Schematic https://cdn.groupbuilder.com/groupdiy/u/39511/58d1402a08c1c.pdf

Also to answer your question the D87 is an authentic reproduction of the original vintage U87
I actually removed the labeling U87a from my website as it confuses people ( thanks Henk)
it was based on the oldest Neumann accurate schematic available which is revision 16 ,
which has a 24V zener,the only thing that was done is to include the better phantom power filtering from revision 21 and put it in the older revision  and then bypass the battery meter wich was not needed here,
the schematic is also available in the first page, 
Best,
Dan,


here are the 2 composite shcemo for your reference ,

Reference Version 16 Schematic:  https://cdn.groupbuilder.com/groupdiy/u/39511/58d1402a02163.jpg

Manual and Version 21 Schemo : https://cdn.groupbuilder.com/groupdiy/u/39511/58d028199494a.pdf

 

[bnwitt]

Dan,
Thank you very much sir.  And also thank you for the very fast shipping of the PCBs for this project.
Barry

 

[micaddict]

Hey,

I will order a package of SYT-5 clean Body's from ShuaiYin Electronics.
SORRY CHUNGER, they have lower Shipping costs for a German delivery.

Is someone out of Germany interested in dividing shipping costs?

Prices for each Body 3rd Generation like in Chungers Store would be priced as shown below:

Body 60,50 USD
Schockmount: 16,80 USD
Shipping (for 5 body's): 95,00 USD

Greatings....

Um ... hello there. I'm in the Netherlands and I have ordered from Chunger. Yes, shipping costs were steep indeed.
But does your direct order concern third generation, too?
Also, is there any consensus about why and how they arrived at a third generation in the first place?

 

[micaddict]

In any case, I'd start a new thread.

 

[fgan81]

Group Order SYT-5 Body.
I just started a new topic:
http://groupdiy.com/index.php?topic=63542.0

 

[aclac]

HI. Just finished U87 clone and one question. I think, that my pattern polar doesn't work as it should. Can OMNI- position be about 8 dB weaker, than other positions? I mean, that when I make for example weak noise to front capsule, this is also weaker, and back side much weaker, when I turn around it and make same kind of noise... any suggestions?

CARDIOID and 8 working as they should, but OMNI has weaker output.

EDIT: I didn't get 60M (R4 and R5), they are 70M thick film resistor... can this effect something weard?

Omni can be weaker. Did you tested it on your voice? If so, main difference is in proximity effect - which isn't present at omni.
70M resitors wouldn't affect anything, not with that small difference in resistance .  If you would use at least 100M, you could only increase time of switching between patterns. Neumann use 68M.

Thanks. I found problem and solved it. The RK-87 capsules backplates has same potential all the time. I found extremely small metal particle between plates and removed it... now it's okay  Happy man, I have pair of those goodies now!

 

[Pip]

I have read a few comments that this build has low output/sensitivity.  Have any of you builder found that to be the case?

Compared to what? A U87Ai yes it does a U87i not really! Read through the early part of the thread and look for posts regarding capsule bias voltage.

 

[hugo]

Hi all,
I have now all components, but i have a big hesitation to start, before checking this with you...
I took an CEK-89 capsule, and just after this i saw the microphone-parts rk87 capsule, which is cheaper and is made for this project..
Should i start with my CEK-89, or should i replace it with RK87 or K87i capsule ?..DOes anybody have informations on it ?
Thank you
Hugo

 

[Murdock]

I don't know for sure, but I think you need a capsule with two electrically isolated backplates if you want an "original" U87.

 

[micaddict]

Yup.

 

[hugo]

Hi,
Because it was already ordered and delivered, i started the build with my CEK-89 from Peluso.. I do not understand how to wire it, because i have only 3 wires instead of the 4 needed..  I tried to connect the capsule with the front and rear diaphragms, and i connected the side wire to the FBK.
After calibration, i have a shhhhhhhhshhhhhhshhhhh + little bit of my voice when i speak in the front of it. The mic becomes silent during 1 second when i change the mode. Can this be induced by the capsule, or may i try to find the issue inside the mic ?..

 

[micaddict]

As stated earlier, for a vintage style U87 you need a capsule with isolated backplates.
Those have four wires.

 

[ln76d]

There are two solutions, make it cardioid/omni with current capsule or buy different capsule.
I can give you adress on PM, where you can buy capsule like mparts RK87 for 50$, but i don't know does it have isolated backplates, you will have to ask seller.

 

[hugo]

thank you very much, but i already ordered the mic parts RK87 to solve this issue.
Thank you