OPEN SOURCE DIY Mic Project - ORS 87 - Stripped Down u87

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Thanks all! Yup, first one is real 87. Both recorded at the same time. Just done super quick as a test, not in gig mode. I just hand held the ORS87, so not scientific at all. Definitely more sibilant, but workable. Would like to hear a better capsule in here.
2n3819 Bias set at about 8.4v
Haven't really compared noise vs the LSK-189 yet.
What I hear is the ORS87 has the foundational sound of a real 87, even with what is about $125 in parts, which is crazy when you think about it. Because it shows, at the same time, how simple the 87 is and yet also how much it takes to go from 90 percent there to all the way. And yet, I think there's still plenty of ground to gain here.
My consideration comes down to the question of how good a spare it is: Could I dub one in for the other, if need be? And I think, for example, if a client told me they changed the interest rate on an auto loan and I need to recut a sentence or two, I could cut that new donut on this ORS87 if I had to and get a close enough match to the original that the end listener wouldn’t be able to tell. Could I gig with this mic? I think so.
I’m just surprised this old CAD body sounds this decent. I had written these things off years ago.
I think the big takeaway from this build is that I can now definitively say that I like the Neutrik NTE 10/3 better for the 87 sound than the Ali T-13.


UPDATE: After spending a little more time comparing it to the 87, with a rested voice, I don't think it's as close as I first thought. I blame my exuberance. I think there's still midrange-damping happening with this headbasket, and the capsule is still average at best. But I'm still very enthusiastic about what it does sound like. I'd be willing to take this mic on a trip in case it was needed and not worry if anything happened to it.
 
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Hi there,

Just chippin'in. I have worked on a version of a U87/U87Ai, I made my own PCB's.
I used the Neutrik 10/3 in most of them. They sound really good compared to a genuine Neumann U87Ai. Hard to beat the real Neumann Capsule sound though. So +1 vote for Neutrik.

What baffles me a bit in this open source U87, is the need to add so much capacitance at C3-C4-C5-C6 (C110-1uF/50V on original Neumann). But hey! Tweak along and have fun guys.

PS: sadly I can already see the "Stripped Down U87 PCB's" adds for sale on the net (vultures).😂

M
Check this on the chat best
 
where did you find that (updated) Khron's BOM !?
Could you point me to it or having a BOM file to share...

thanks
0-0
Khron discusses what he'd change from the original BOM here:
https://groupdiy.com/threads/open-source-diy-mic-project-ors-87-stripped-down-u87.86814/post-1144058

And Homero's BOM, which followed this discussion can be derived from his schematic. This is what I used on my two Homero PCB builds.
https://groupdiy.com/threads/open-source-diy-mic-project-ors-87-stripped-down-u87.86814/post-1144815
 
Screenshot 2024-05-01 at 6.58.43 PM.png
My buddy Duffy Weber over at Hula Cow Studios decided to spontaneously create an ORS 87 board, too.
This is really what I was hoping for... that people would get excited by this project and want to jump in, take part and make something. Duffy's never done a mic before but he's designed stuff like T-power to Phantom adapters and I can tell that now's he's gotten bitten by the mic DIY bug, he's hooked. He also adapted a 10db pad board from another project of his for this circuit as a daughterboard. So, fun stuff happening.
 
Can't wait do hear more about it! Thank you


As an amateur, I feel like I'm progressing more and more in my overall understanding of microphone construction. I find this OSR87 chat very educational and I would really like to thank all of you for sharing your knowledge. Your recipes are little treasures. DIY power to the people becomes = DIYPTTP. Big up and respect!!!

This body is great because the grill is very thin and open and it seems to me that the resonance doesn't affect the sound to much...
https://french.alibaba.com/p-detail...0.wholesale.popular_products.8.733a27b7XrzI1U

This mic seems to be good too
https://www.alibaba.com/product-detail/MY-MIC-Nouveau-modèle-M3-Professional_1600280813310.html?spm=a2700.9114905.0.0.1Mip7G

Peace out!!!

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Why "160+V" for the DC blocking capacitor going to the transformer, though? This not being a tube mic...
I think he saw that big honking 400v cap on One Room Studio's original build and he had a certain other 1u cap in mind, maybe the ERO 1839 160v, which I really like for this purpose. I told him it didn't need to be that big, but I get it, the big cap looks cool. I'm thinking of building one with this massive 1u PIO cap I have sitting around, just for fun.
 
Can't wait do here more about it! Thank you


As an amateur, I feel like I'm progressing more and more in my overall understanding of microphone construction. I find this OSR87 chat very educational and I would really like to thank all of you for sharing your knowledge. Your recipes are little treasures. DIY power to the people becomes = DIYPTTP. Big up and respect!!!

This body is great because the grill is very thin and open and it seems to me that the resonance doesn't affect the sound to much...
https://french.alibaba.com/p-detail...0.wholesale.popular_products.8.733a27b7XrzI1U

This mic seems to be good too
https://www.alibaba.com/product-detail/MY-MIC-Nouveau-modèle-M3-Professional_1600280813310.html?spm=a2700.9114905.0.0.1Mip7G

Peace out!!!

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These are great. I have a few of these bodies in silver, and I like them quite a bit for this kind of thing. They're about 3/4 the size of a u87, more the size of a u89 and the headbasket seems to have the right geometry, and they're quite affordable, too. But I do really like it better in black.
 
Why "160+V" for the DC blocking capacitor going to the transformer, though? This not being a tube mic...
In the original scheme, Neumann used a polarized, electrolytic capacitor with tantalum or aluminum, for the transformer coupling. With a appropriate operating voltage for this circuit.
This capacitor (which also interacts with the transformer) also contributes with something to the characteristic sound of U87.
Between the different types of capacitors, there are differences in parameters, which produce differences in sound, more obvious or more subtle, have been discussed countless times, everywhere. We now leave Magic Mojo aside.
If you want to get the U87 sound, a simple logic would involve using the same components as the original or as similar as possible.
But everyone has other beliefs, preferences, hears differently. So everyone does what they want, how they like, with what components they have at hand.
✨
We like to experiment, modify even expensive newly bought gear.
It's in our nature as DIY maniacs.😁
 

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These are great. I have a few of these bodies in silver, and I like them quite a bit for this kind of thing. They're about 3/4 the size of a u87, more the size of a u89 and the headbasket seems to have the right geometry, and they're quite affordable, too. But I do really like it better in black.
@Wordsushi what’s your favorite cardioid only u87 body so far?
You seem to have tested a lot!
 
@Wordsushi what’s your favorite cardioid only u87 body so far?
You seem to have tested a lot!

I try to guess 😁
HL-95
Yup!
My favorite, so far, is indeed the HL-95. It made my 87 clones sound more accurate and it’s the closest in appearance to the real thing. A steal at $60.

My 2nd fave are the 3/4 size 87-style bodies that have the right headbasket shape. These are plentiful, easy to work with and sound good. Mics in these don’t sound quite as “big” as they do in the larger HL-95, but these can be snagged for around $30 as a full mic you have to gut and are everywhere.

One thing I’ve noticed across many, many mics is that headbasket size and shape makes a lot of difference. The CAD GXL2200 body I built an ORS-87 into has a smooth angled, not chiseled, headbasket and it feels lacking in that midrange bite you expect from an 87. It’s not a bad sound, but not exactly an 87 even if the tone is on point.

I really like the TLM-103 style bodies out there. The counterfeit 103’s have a very accurate headbasket, down to the correct meshing. And the slightly smaller 103-style bodies that are all over Ali also sound good. I mention this one because my buddy Duffy is laying out an ORS87 board that will fit in one of these 103 bodies.
 
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