Neumann Vintage U87 Clone : Build Thread.

[LesPaul]

Hello

Finally got my hands on a donor body for this build. But it has no housing for the transformer, it's just one big space. Should I build a housing for this, or doesn't it matter?

 

[HellfireStudios]

It doesn't matter. In fact, I was able to fit a larger transformer in mine (Peluso BV8P-S) by removing the cover. The internal pics of the U-87 show no cover on their x-formers. If it's good enough for those mics, it's good enough for my mic. Just glue, epoxy, or strap the new x-former into place.

-James-

 

[LesPaul]

Thanks

Less work ;D

 

[benlindell]

Just wanted to drop by and give a big THANKS to poctop for this project, I just finished my pair off and they worked perfectly right away! I'm taking them with me to the studio tomorrow and will shoot them out with our real 87(ai I think). I left the aurycle capsule in one and the rk-87 capsule in the other, interested to hear what the differences are, what do you guys want to hear? I was thinking vocals and maybe drums (in a room mic kinda position).


Finishing up my custom u87s finally! #diy #studio #microphone by benlindell, on Flickr

 

[poctop]

very Nice Build Ben , I am happy everything went well with your build , I really hope you will enjoy the mic ,
Really nice taken picture also very artistic , i might be using it in my thread ,
Keep us posted,
Best,
Dan, 

 

[Melodeath00]

Hi everyone,

I'm looking into getting into DIY mic building, but as a newbie I don't know much about building or electronics. I know what capsule, body, and transformer I want, but beyond that I'm a little lost. I'm mostly interested in tube mics, but I imagine tube mics may be harder to build than a FET mic like this. My question is, do you think this U87 would be a good first project for a newbie, or is it still too complex for someone new to this stuff?

Thanks so much

 

[Dylan W]

Hi everyone,

I'm looking into getting into DIY mic building, but as a newbie I don't know much about building or electronics. I know what capsule, body, and transformer I want, but beyond that I'm a little lost. I'm mostly interested in tube mics, but I imagine tube mics may be harder to build than a FET mic like this. My question is, do you think this U87 would be a good first project for a newbie, or is it still too complex for someone new to this stuff?

Thanks so much

Can you solder? A guitar pedal is a good start, and is pretty forgiving for learning assembly skills. My first project other than fixing guitars and cables was the Bo Hansen DI, which is another great beginner project. Inexpensive and sounds great to boot.

Once you've got your feet wet with that, a mic PCB like the U 87 is not really more difficult, but capsule leads, etc are a little delicate. A mic is probably less forgiving if you haven't done anything similar before. I would do a few solid state projects, and then a few solid state power supplies, before you think about dealing with tube B+ voltage.

Dylan

 

[kante1603]

Hi,

welcome to the forum.
I absolutely second Dylan's recommendations.
Even if this mic is not hard to solder you can run into serious problems thinking about the high impedance part,the capsule's enormous sensitivity,the biasing and the overall costs of it in general.
When it's coming to tube stuff and you don't know what exactly is going on in the high tension part you will risk your health-I'm not joking here.
So best is doing some of those smaller builds and learn from that.And you should read some books,there are billions out there and try to understand the circuit like where does my signal go and why.At least you have to know basic things like ohms law etc.
A di box like the bo hansen 1975 is a perfect beginner's project,and you'll have an amazing sounding every day tool (believe me,I've built 8 of them now and never touched any other di since then).
Next step could be a mic preamplifier like an SSL 9k or so,then maybe a nice compressor like the well-know 4k mixbus.

Most of us went this way and learned a lot from them,some of us are really experienced builders and designers now.
It just takes some time and a bit of patience, you'll get infected by our beloved "diy-virus" soon!

Best regards,

Udo.

 

[BigDad]

Hi Melodeath00,

Build an u87 will not necessarily more hard than build a guitar pedal but request more rigorous.
I think that the most important is mainly to feel good in what we do ! Use protoboard with wire or old components used that leads you to solder !
Honestly you may totally try the experience I encourage you to do that, but in case of problems it will be hard to find the breakdown if you haven't many experiment's !

 

[kante1603]

Hi Melodeath00,

Build an u87 will not necessarily more hard than build a guitar pedal but request more rigorous.

......hmmmmmmmm..........

.................., but in case of problems it will be hard to find the breakdown if you haven't many experiment's !

Yes..........

Udo

 

[HellfireStudios]

It is beacause of the difficulty of properly biasing the FET that makes this project a bit too advanced for a novice. An oscilliscope is needed to do it the right way. If I didn't have so many projects that required oscilliscope biasing, I don't think I would have been able to justify the added expense.
Tube mics are more dangerous, but w/ some basic electrical knowledge (like waiting for capacitors to discharge before touching anything, properly cleaning the high impedance side of the circuit to reduce noise, etc) they are much easier to build into a donor mic than the U-87 circuit.
I second the idea of building something way easier like an effects pedal or D.I. box. Pedals are where I started, and now I can't stop modding everything in my studio.

-James-

 

[Melodeath00]

Hello, thanks for all the replies! To answer the question, yes I can solder, but I have no idea if I have "good technique" or not. I built one Reamp box before (the opposite of a DI), and while it worked, it didn't sound good at all (there was no bass, very harsh treble, noise). I had several people look over it, and no one knew what was wrong, which sort of turned me off from DIY. Perhaps it was a defective transformer. Either way I was left with a no-good Reamp box. Since I can't read schematics, I think I wired it up based on pictures. Much like I would do for the U87 or any tube mics.

I didn't know exactly what biasing the FET was, and I do not have access to an oscilloscope, so perhaps this is not the beginning project for me...

 

[HellfireStudios]

You should learn to read a schematic before attempting mic electronics. It may look daunting at first, but in reality schematics tend to be multiple electronic circuit "blocks" put together. A google search should give you plenty of info to start with. Don't get impatient, the more you do it the more it will sink in, and realize that you may have to debug the circuit after you have built it (a pain, but it happens more often than we like to admit).
The Ibanez tubescreamer has LOADS of info on the web about its design. It might help to build one and learn how the circuit works at the same time. That way you get your feet wet before moving on to the dangerous/difficult.
BTW, never get your feet wet before playing with electricity

-James-

 

[benlindell]

Hey guys, I made a quick post shooting out my 87s. I apologize in advance for having to use my voice, I'll do more shootouts as I use these guys in sessions.

http://www.benlindell.com/2012/11/custom-87s/

 

[Dylan W]

Great clips, Ben. The RK-87 is really pretty good. I was able to guess the Neumann in all the clips but one, but the RK-87 version is extremely close, especially with a much cheaper capsule.

I suspect we might see more of a difference in diffuse field sources with extreme dynamic range, which IME is where high end mics tend to excel. Noticed a bigger difference between capsules in Marc's test, where the Neumann was pretty clearly better. I'm amazed though at the cost/quality ratio. Certainly close enough to get usable vocals.

Dylan

 

[poctop]

Hey guys, I made a quick post shooting out my 87s. I apologize in advance for having to use my voice, I'll do more shootouts as I use these guys in sessions.

http://www.benlindell.com/2012/11/custom-87s/

Ben you page is amazing ,  great Job , and great link,  I hope you will enjoy the mic ,
Big Thanks for all your effort on this , this is very appreciated,
Kudos,
Best,
Dan,

 

[poctop]

Hey guys, I made a quick post shooting out my 87s. I apologize in advance for having to use my voice, I'll do more shootouts as I use these guys in sessions.

http://www.benlindell.com/2012/11/custom-87s/

Ben these are very amazing results you have there ,  The RK-87 seems to have a more air control than the Chinese one for sure , but WoW very impressive , Actually My Vintage (45V+ Polarisation) sounds more like the clone  ,  very warm in the mid range but not as airy, a bit darker than the sample i have heard from the AI ,  I am posting here a tweak that could even make it better to match the AI you have is in reducing the negative feedback cap just a notch,  this would bring back a bit of sheen and you could be really surprised,
note that the Original capsule K87 at 800$ need this compensation a that level but you could give it a shot ,
but for a 100$ capsule this is Fantastic,  I have to say that i still have an affair with the good old nude brass mic body  8)

I am attaching a post from Matador ( Thanks Matador)  about negative feedback cap and adjustment tweak you could do would make you even happier.  thanks for this great rewards to me 

3) Reduce negative feedback:  as I hinted at earlier in the thread, you can decrease the value of C6 (or remove it entirely) and it will give you back 3dB to 6dB, however the sound also changes as well.  If you like the "EQ-ed" sound, lowering C6 will take that away, however the mike will be hotter.  If you like/want the "air" it's a very simple mod to do and doesn't require any expensive or complicated circuit changes.  The sound change is FAR more drastic than #2 above (removing C6 can make it sound like a completely different mike).

 

[Matador]

I had the opportunity to repair a real U87.  Serial number puts this particular one as being manufactured in 1971.  I took a few pics of the inside in case anyone wants to know what an original looks like inside.  This one needed a capsule replacement, as the original was cutting out due to severe contamination between the gold sputtering and the edge of the capsule.

A few shots of the capsule assembly from the head basket:

One of the interior:

A shot of the new capsule:

The new capsule sounds pretty damn good.  I also ordered a pair of tskguy's capsules that I'd like to try in this mike as well.

 

[wave]

Pretty sweet Matador.
Is that a Peluso capsule? I'm really interested to hear one of Eric's capsules in this mic too!

Dave

 

[Matador]

Pretty sweet Matador.
Is that a Peluso capsule? I'm really interested to hear one of Eric's capsules in this mic too!

Dave

Yes it's Peluso's P-K87i.