Neumann Vintage U87 Clone : Build Thread.

[kante1603]

Hello Pip,

I think I've covered all(!) issues and workarounds concerning the B2Pro-Body in this thread precisely,last time even on this page.
It is easily doable and works out great.I have a perfectly running mic here and I'm doing another three at the moment (have to wait for some parts but will be done soon).
Maybe you've got one of those B2 versions that have that big white plastic piece at the switch position?
Remember there are several versions on the market,I personally know there are at least 4 or 5 existing!
I have posted a lot of pics here so you can compare them with your build.

Udo.

 

[ramshackles]

Optimum body would be the SYT-5 which Chunger is selling. This is for the large PCB though..

I've built two in that body with the RK-87 which is a very nice capsule indeed.

 

[Pip]

So I have achieved success!

Thanks to all in the forum who made this happen. Thanks to Dan and Thanks to Chunger for his alternate build thread. Also thanks for allowing me a little rant :-[.

I remembered that I had a Nady 900 mic in the closet. So I dug it out to see if it would work for this as I really had enough of trying to make the Behringer work. It was meant to be because when I opened the box there they were a pair of Dan's tapered PCB's I had bought and totally forgotten about. I also feel that the Nady is a more robust donor than the Behringer. But it does not have any switches so you are resigned to the jumper blocks for these functions. But I think I'm OK with that.

Long story short I made this my donor and know have a U87 clone that is working great. It still needs some tweeking (output seems a bit low so I need to do some of the cross checks)(transformer is wired correctly) and I may opt to change caps at some point to the alternate versions from the BOM. But it works! And there was great rejoicing!

I am fortunate to be able to say I own a Neumann U87i and will do some A B testing in the near future if time allows. I will try to maybe post some listening material as well.

I also want to share how good I think the microphone-parts capsules are. In my opinion they are of great build quality and definitely affordable. Plus there is a lot of helpful support on the website.

Thanks to all again.

 

[kante1603]

Hello Pip,

could you please answer my question which version of the B2pro you tried to use (big white plastic part or not inside)?
This would help builders to avoid making mistakes,especially over here in europe.

Thank you,

Udo.

 

[Pip]

Hello Pip,

could you please answer my question which version of the B2pro you tried to use (big white plastic part or not inside)?
This would help builders to avoid making mistakes,especially over here in europe.

Thank you,

Udo.

It is the one with the black plastic part which may have been white in some models. It has a pin array that hooks the head basket assembly to the mic body, much like a real U87. It has a series of grommets that are in the base of the top assembly that holds the pin receivers. The wires from the PCBs are soldered to these grommets then above that moving towards the head assembly there is a cavity were the components of the stock circuit are soldered to them and they in turn are soldered to the pin receivers. The switch array is in the head basket assembly. Again if you are having trouble visualizing this it is much like a true U87 in concept only made out of very cheesy easily melted plastic.

This would be OK if there were 11 pins but there are only 6. You need four for the capsule and seven for the switches. Unless I am really missing something. 

 

[Pip]

Here I have some pics that should help.

 

[Pip]

One more.

 

[kante1603]

Hi Pip,
great info,thanks a lot!So we have another (!) version of the B2Pro!!!
Meaning five or even six of them.....sh.....!
Mine are completely of metall with no thick plastic parts which gave me a lot of additional workspace.
I have two versions already but have seen way more (look at the "early" days here in the thread if you like,there are a lot of pics to find).
Also my version has thicker walls than the real ones,I have them all here,plus they're on sale for less than 100 Euros incl. case,popfilter (foam) and a shockmount.So it's the best donor mic over here in europe concerning price.
Again thanks for letting us know!
I wonder what a seller would say of one of us starts to unscrew the body in his store,...... ;D ;D ;D

Cheers,

Udo

 

[kante1603]

It is easily doable and works out great.I have a perfectly running mic here and I'm doing another three at the moment (have to wait for some parts but will be done soon).

....and so I did it...the pics:










Cheers,

Udo

 

[JessJackson]

couple very simple questions.

its fet biasing time for me...

1. do the switch wires need to be connected to the boards, at the moment mine are not yet.
2. does phantom power need to be connected when injecting 1k tone? this doesn't seem to be documented.
3. xformer should not be connected yet?
4. capsule should not be connected

 

[kante1603]

Hello,

couple very simple questions.

its fet biasing time for me...

1. do the switch wires need to be connected to the boards, at the moment mine are not yet.

No,not needed.

2. does phantom power need to be connected when injecting 1k tone? this doesn't seem to be documented.

Yes.otherwise the circuit doesn't work.

3. xformer should not be connected yet?

You can leave it unconnected for now.

4. capsule should not be connected

Exactly,the signal generator replaces the later capsule signal.

Cheers,happy biasing,

Udo.

 

[Pip]

couple very simple questions.

its fet biasing time for me...

3. xformer should not be connected yet?

Well unless you are doing it aurally. This assumes you are using scope. I prefer doing both. I also think that I would want the circuit properly loaded for biasing. So in my opinion on this issue I would hook up transformer.

All the best.

Udo mics look great! ;D

 

[kante1603]

Well unless you are doing it aurally. This assumes you are using scope. I prefer doing both. I also think that I would want the circuit properly loaded for biasing. So in my opinion on this issue I would hook up transformer.

All the best.

Udo mics look great! ;D

Hi Pip,

you're right,needed when doing bias by ear of course,sorry,didn't think of that.
I did mine with a scope and they worked out exellent without the transformer attached,no issues.

Thanks for the nice words!(Yes,they're from B2Pros,hahaha...... ;D).

Have fun,

Udo.

 

[JessJackson]

Thanks, I used a scope and I got it perfectly to where the peaks and troughs clip at identical times when increasing the tone amplitude.

 

[kante1603]

Thanks, I used a scope and I got it perfectly to where the peaks and troughs clip at identical times when increasing the tone amplitude.

Excellent!

Udo

 

[North]

Has anyone swapped out this board in a SP C1 using original C1 trans and capsule? Can it be done?

 

[HellfireStudios]

Has anyone swapped out this board in a SP C1 using original C1 trans and capsule? Can it be done?

As long as the transformer is a 10:1 ratio you'll be fine. The capsule will most likely not work. You need isolated backplates to acheive correct polar pattern switching. Stock chinese capsules don't tend to utilize this construction.

FWIW, skimping on the capsule and transformer is probably not the way to go. Those two components have the most impact on the sound of a mic, and the money spent on great parts will be worth it in the end when you have a recording instrument instead of just a microphone. Your results may vary...

-James-

 

[North]

10:1..got it. I was curious about this as the stock C1 capsule is not entirely bad and Just having the cardioid polar pattern would not be a big deal to me. I thought it would be nice if I could replace parts as I go along, and sample clips with each stage and document the differences. Thanks

 

[poctop]

10:1..got it. I was curious about this as the stock C1 capsule is not entirely bad and Just having the cardioid polar pattern would not be a big deal to me. I thought it would be nice if I could replace parts as I go along, and sample clips with each stage and document the differences. Thanks

You can sure use the mic in cardiod only if you have the stock capsule ,
good idea,
+1
Dan,.

 

[North]

Dan are saying I can use with stock "C1" capsule? .... I was thinking I would just not route what would normally connect to the rear grid. Ive got a c1 and/or an Avlex avs80 as doner bodies and capsules. Is there an easy way to determine the transformer ratio's in these mics?