Neumann Vintage U87 Clone : Build Thread.

[poctop]

Hi guys!
  Had a chance to AB the mic at a friends studio.
did a few scenarios.  For vocal work we set it up as close as physically possible to a Pelusso 2247.
The mics were very very close in sound.  Eerily close and could have been a useable overdub substitutes in a pinch.  I felt like a proud father with my self made mic; we were both stunned with the nice results.
  One observation was that the polarities were opposite.
Do I need to go in and flip either the primary or secondary sides?  Or leave it?
  Also, a purely cosmetic concern, I wired in switches, but am tempted to take em out and put the molex headers back in.  It's no biggie to open the mic to make connections, and I was unable to show the guts off to friends!  If I do this, I'll have to make some fancy badge to cover the holes.

the polarity can be chaned by inverting pin 2 and 3 on the xlr connector in the mic but just make sure you wired it right ,
Hope this helps ,
DIY Rules 
Best,

 

[andyfromdenver]

Thank you Dan.  I'll open it up and check. 
DIY rules with a mighty sword

 

[kevinkace]

Polarity can get swapped at the transformer as well.

 

[andyfromdenver]

Thanks Kevin.  Looking back at my pics (in phone).  Pin 2 is definitely hot, so I'll swap the transformer secondaries I guess (they'll be easier to get to anyway).
Polarity is a google rabbit hole.  One thing I read is if the polarity is non inverted you can tell when you talk into mic with headphones and it sounds good vs flipping polarity.  Or Ethan Winer has a schematic for a tester, which would just be a fun lil build...

 

[wave]

andyfromdenver,
What kind of transformer are you using in your build?

Dave

 

[andyfromdenver]

The Peluso t87

 

[wave]

So do you have a data sheet for it that shows the primary and secondary wire color code?

I know you had that drawing of it a couple pages back but are you sure that is the correct color code for the trafo pinout?

Dave

 

[andyfromdenver]

@ Dave
Post #1420 page 72 has a schem. attached.
(Was unable to copy paste)
Plus here's how I did mine: (see pic)
Thanks!!
Andy

 

[wave]

SO I'm pretty sure you're wiring the T87 and the XLR correctly but here's a hookup diagram just for kicks



Report back if this is not how you had it wired

Dave

 

[andyfromdenver]

Yeah.  Weird.  My friend had homebrewed pres and stuff maybe the problem wasn't on my mic end.  I'll investigate more, thanks guys!
  That was really awesome to whip up the wiring diagram, thank you very much!
Andy

 

[HellfireStudios]

Yeah.  Weird.  My friend had homebrewed pres and stuff maybe the problem wasn't on my mic end.  I'll investigate more, thanks guys!
  That was really awesome to whip up the wiring diagram, thank you very much!
Andy

Were you using a modified Golden Age Pre-73? I had to change polarity on both of Pre-73's to be in phase with a JoeMeek OneQ I already had. You could always test the DIY pres with some known "pin 2 hot" pres, and get your answer.

-James-

 

[poctop]

I have been RE-Double-checking the polarity on the U87 design and the label on the pcb is Correct hot,cold,gnd  not the number that i removed from the silk screen in the version 2 .

Best,
Dan.

 

[andyfromdenver]

Yeah.  Weird.  My friend had homebrewed pres and stuff maybe the problem wasn't on my mic end.  I'll investigate more, thanks guys!
  That was really awesome to whip up the wiring diagram, thank you very much!
Andy

Were you using a modified Golden Age Pre-73? I had to change polarity on both of Pre-73's to be in phase with a JoeMeek OneQ I already had. You could always test the DIY pres with some known "pin 2 hot" pres, and get your answer.

-James-

Hi James.  No it was some API ish DIY thing I believe.
When I get home I'll borrow a friends mic and check.  On tour for ~4 wks!
The Music Tapes.  Fun times

 

[poctop]

The Store is back online,

Happy New year All, 
Best,
Dan,

 

[sr1200]

Had a session tonight.  Hooked up the U87 clone along with a few other really good mics.  87 clone beat em all out.  Client was amazed that this was an in-house built mic and VERY happy with the tonality of it.  Thanks so much for this awesome project! 

 

[atticmike]

Guys, I'm simply stunned. The mic's performed beyond my expectations! Thanks so much to everyone that has helped me procure the parts and made this project possible, Dan for the board and Eric for those amazing capsules in particular! Though I haven't had much time to record a few samples, here's a quick recording in German: http://dl.dropbox.com/u/70609905/testvox_customu87_1073.wav

No EQ, no compression, straight into the Neve pre.

Enjoy.

 

[tskguy]

Mike,

Sounds really really great!! Glad to see it finished. Looking forward to some more samples.

Eric

 

[Che_Guitarra]

I've not yet looked at every page of this thread (to see if it's been done before), but i'm wondering if my Rode NT-2A would make a good candidate for this U87 overhaul?

Since I got my Pearlman TM-1 my Rode sees no action at all - if I could rebuild/refurb it to be a little darker in tone I think it'd find a lot more use.

 

[HellfireStudios]

I've not yet looked at every page of this thread (to see if it's been done before), but i'm wondering if my Rode NT-2A would make a good candidate for this U87 overhaul?

Since I got my Pearlman TM-1 my Rode sees no action at all - if I could rebuild/refurb it to be a little darker in tone I think it'd find a lot more use.

You can find the PCB measurements/mounting screw locations in this thread, and find out if it will work in your mic. The RODE might have unique construction that could deter your progress, though. Only one way to find out...

The capsule will still need to be changed to get the most from the mic as a U-87 clone. The RODE capsule is a smaller size.

You may be better off finding out what circuit changes might help your RODE sound its best before the expense/time of a total overhaul.

-James-

 

[DUDE GUY]

Hello,

I'm trying to source the pattern and pad/filter switches for poctop or chunger's switch pcbs and I found these switches on mouser. Can anyone tell me:

Will this work as the pattern switch?

http://www.mouser.com/ProductDetail/CK-Components/ET03SD1ABE/?qs=sGAEpiMZZMtn8lxF5bBjIQWcN3oQfoXv

Will this work as the pad/filter switch?

http://www.mouser.com/ProductDetail/CK-Components/ET01MD1ABE/?qs=sGAEpiMZZMuIC3ROaEqRYe45DaHRdpBu

Thanks,

-Kevin