Neumann Vintage U87 Clone : Build Thread.

[andyfromdenver]

Thank you very much Krumlee.
Yeah, I guess having the option in there is nice.
And maybe my little glow-y idea is no good.
Crud...  ha jk.
I just wanted to bling it a little and put some DIY pizazz into it.
My first one has the peluso capsule and transformer combo. 
I am tempted to ab it with the stock capsule in this donor.
Gonna just go in stages.
The funny thing is, I came at this groupdiy site totally backwards from most.
I just added a two tube spring reverb to a Silverface champ (calling it the Michael Phelps)
But give me some little LEDs and transistors and I'm like whaa??

Glad I asked and I appreciate the advice.
Tbc

 

[Krumlee]

Andy,
Nothing wrong with diy pizazz - and each build should be personal. Some big name installation artist has done your idea - at least in the name of conceptual art!
- http://www.moma.org/interactives/exhibitions/2013/soundings/artists/9/works/
Regards...

 

[Krumlee]

I just want to mention another possible donor, especially for people in Europe. Someone asked about this a while back.

The Golden Age Projects FC1 (mk II) has identical metalwork to the MXL 2001 - I've just used one for my latest build. No switches, but it has a metal can for the transformer and the screw holes for the boards line up perfectly (which I don't think is the case for the Behringer bodies). They also do an FC2 model which has pad and low cut switches. It appears to be an FC1 with switches - but I've not inspected one close up.

These come up fairly often on ebay (UK) and they sell for cheap. If you're on a really tight budget and only need cardioid then you could try the stock capsule. I've just tested the one from my latest build (FC1) and it actually sounds OK. Compared with an RK87 capsule I'd say it sounds a bit more vintage (possibly because it's 6 micron) and with less low end. But it's definitely usable.

 

[mrdarwin]

Hi everybody!
I bought my U87 clone 3 months ago and everything was fine, good sound etc...
After two weeks without use, my mic now makes some noise and pop!
Noise and pops disappear after 20min, sometimes come back...
Does U87 need a warm-up? Do I have to swap the FET? Electrolytic caps? Voltages are ok, but voltage at drain of FET isn't stable... due to the capsule? If I swap the FET, do I have to disconnect the capsule to calibrate voltage drain with the trimmer?
Thanks...

 

[poctop]

Hi everybody!
I bought my U87 clone 3 months ago and everything was fine, good sound etc...
After two weeks without use, my mic now makes some noise and pop!
Noise and pops disappear after 20min, sometimes come back...
Does U87 need a warm-up? Do I have to swap the FET? Electrolytic caps? Voltages are ok, but voltage at drain of FET isn't stable... due to the capsule? If I swap the FET, do I have to disconnect the capsule to calibrate voltage drain with the trimmer?
Thanks...

this would be a classic case of moisture build up on the capsule or simply contamination of it ,
if you change the fet you need to re-Bias without the capsule intstalled,
Best,
dan,

 

[mrdarwin]

Hi everybody!
I bought my U87 clone 3 months ago and everything was fine, good sound etc...
After two weeks without use, my mic now makes some noise and pop!
Noise and pops disappear after 20min, sometimes come back...
Does U87 need a warm-up? Do I have to swap the FET? Electrolytic caps? Voltages are ok, but voltage at drain of FET isn't stable... due to the capsule? If I swap the FET, do I have to disconnect the capsule to calibrate voltage drain with the trimmer?
Thanks...

this would be a classic case of moisture build up on the capsule or simply contamination of it ,
if you change the fet you need to re-Bias without the capsule intstalled,
Best,
dan,

Thanks for answer, Dan.
What do you mean: "contamination"? radioactive??? ;D
Seriously, I leave others mics I built in my studio with no problem of moisture... aaargh. Bad capsule? When mic does "pop" voltage on drain follows these pops. Moisture can be visible on a capsule?

 

[OPR]

Great Project Dany!
Ive been making these for lots of people who are not DIY Inclined and they are loving them!!
Keep up The great work! 8)

 

[poctop]

Great Project Dany!
Ive been making these for lots of people who are not DIY Inclined and they are loving them!!
Keep up The great work! 8)

Awesome ,  you are welcome,
Best
Dan,

 

[0dbfs]

Hey Guys, I'm looking to put a several more of these together in the coming months. I used the Aurycle bodies on my last run. Those bodies are nice and tiny which I like but they seem to often be "out of stock". After the mic's had been in service for a while the aurycle headbaskets became "loose" and I needed to re-braze them. No big prob with that and would use the same again.

I am looking for a body candidate which is "as small as possible" and also uses a swivel mount instead of shock mount (for space), and fits the tapered PCB's & capsule. It looks like the B2-Pro fits the bill with switches but I'm wondering whether anyone has used a B1 or other small body (B1 looks to be slightly smaller than the B2). Internal jumpers/switches are fine in this case for pad/hpf/pattern.

Cheers!
-jb

 

[burglar]

Hi folks,

will this inductor be ok as a replacement for the ones on backorder in BOM?  http://uk.mouser.com/ProductDetail/Vishay-Dale/IRF03BH470K/?qs=sGAEpiMZZMsg%252by3WlYCkUzRE4pp5rwGkbqNH%252bHKbdcU%3d

 

[Krumlee]

Hi folks,

will this inductor be ok as a replacement for the ones on backorder in BOM?

Yes, should work fine.

 

[poctop]

Great Project Dany!
Ive been making these for lots of people who are not DIY Inclined and they are loving them!!
Keep up The great work! 8)

WoW
D.

 

[poctop]

Great Project Dany!
Ive been making these for lots of people who are not DIY Inclined and they are loving them!!
Keep up The great work! 8)

WoW
D.

Oh Forgot where is the DIY Bias Machine ,
D

 

[OPR]

I use my good old analog oscilloscope  8)

 

[Krumlee]

I've just experimented with another small mod on my D87. I really use cardioid only, so I thought I'd disconnect the rear diaphragm (unsoldered and taped up RD connection). I know that some U87 modders install a switch to do this when the mic's in cardioid mode, and I think Neumann did something similar in later versions (??).

I can't say I noticed any s/n improvement, but the bottom end seems slightly clearer. BIG caveat: I don't have producer's ears, and my brain is easily fooled!

Has anyone else here done this? Can someone smarter than me explain what the effect should be, in theory.

Thanks.

 

[kante1603]

The rear diaphragm is not working when in cardioid mode.
The switching abilities aren't a mod,they are original.
Sad to see how some builders don't use them,especially when it comes to stereo recording techniques like m/s or even Blumlein etc.

Best,

Udo.

 

[Krumlee]

Thanks Udo - much appreciated.

 

[heeters]

Hey guys, Justradios now offers the 220pf, 470pf, and 560pf polystyrene caps with 1% tolerance or 5% tolerance. Which ones would be better to use?

 

[Deepdark]

just found another source for the polystyrene caps. For those interested:

http://www.partsconnexion.com/capacitor_film_styrene_main.html

 

[geekmacdaddy]

Hey Dani and everyone. Built this couple of years ago, and had intermittent problems with low "motor boating" kind of sound with occasional pops…happens all the time now…thoughts?

Thank you.