Neumann Vintage U87 Clone : Build Thread.

Finally got around to putting this together! Just waiting on a capsule and transformer from Peluso which should be here in the next few days! If all goes well I'l build another one very soon. Fingers crossed!

Well, got the capsule and transformer in. I don't have any output and I can't seem to get any voltage to r6 to get too 11.4! When I change the pattern the meters in Pro Tools jump a little, but no output on any pattern. Tried turning pad on and off and low cut off and on. Typical!

Any ideas? I can post pictures of my board if that helps, just don't judge my handiwork!

EDIT: I should state that I seem to get voltage to both backplates, but none at r6. So both boards seem to be getting juice. I will double check everything this weekend when I have some time to sit down with it again.

EDIT2: I think the diode on my AA board is installed backwards. Perhaps this is the reason for my troubles!

I'm trying to wrap my head around hooking up a genuine Neumann U87Ai headbasket to Dany's D-87 PCB's.  There are 7 connection points on the headbasket (which includes the capsule),  but Dany's boards have 11 connection points with the switches and capsule. 

Dany's PCBs:
PAD (2 wires)
PAT (3 wires)  pattern
- OMN PAT 1
- CRD PAT 2
- 8 - PAT 3
LC (2 wires) low cut
RBK - Rear Backplate
RD  - Rear Diaphragm
FBK - Front Backplate
FD - Front Diaphragm

Can someone help me make sense out of how to hook them up? 

This is the portion of the U87Ai schematic that shows the headbasket connections (1-7).

Here are the pins on the Neumann headbasket:

HI. Just finished U87 clone and one question. I think, that my pattern polar doesn't work as it should. Can OMNI- position be about 8 dB weaker, than other positions? I mean, that when I make for example weak noise to front capsule, this is also weaker, and back side much weaker, when I turn around it and make same kind of noise... any suggestions?

CARDIOID and 8 working as they should, but OMNI has weaker output.

EDIT: I didn't get 60M (R4 and R5), they are 70M thick film resistor... can this effect something weard?

i'm so confused by this.  I think there really needs to be some comprehensive info laid out there regarding which bodies fit which boards!!  I just acquired  the Dany's tapered version pcb and so far have only been able to google search confirm that it fits bm600. How bout b2 pro, sty5, mxl 2010, others????  thanks for your clarification!!

Hi!

I ordered the Dany U87 pcb and components from an available mouser cart on the forum. But the two 470pF and the 10pF capacitors I received was not polystyrene capacitor as the build guides (and pcb) says it should be. The ones I received was ceramic. Does it matter? Should I try to get hold of the polystyrene instead? Btw, can't even find 10pF polystyrene on mouser..

The polystyrene are available on Dany's page.

aclac said:

HI. Just finished U87 clone and one question. I think, that my pattern polar doesn't work as it should. Can OMNI- position be about 8 dB weaker, than other positions? I mean, that when I make for example weak noise to front capsule, this is also weaker, and back side much weaker, when I turn around it and make same kind of noise... any suggestions?

CARDIOID and 8 working as they should, but OMNI has weaker output.

EDIT: I didn't get 60M (R4 and R5), they are 70M thick film resistor... can this effect something weard?

Click to expand...

Omni can be weaker. Did you tested it on your voice? If so, main difference is in proximity effect - which isn't present at omni.
70M resitors wouldn't affect anything, not with that small difference in resistance .  If you would use at least 100M, you could only increase time of switching between patterns. Neumann use 68M.

if not using switch, do I just leave the OMN-CRD-8 and LC and PAD as they are on the PCB?

all the best,
J

vinylwall said:

I'm trying to wrap my head around hooking up a genuine Neumann U87Ai headbasket to Dany's D-87 PCB's.  There are 7 connection points on the headbasket (which includes the capsule),  but Dany's boards have 11 connection points with the switches and capsule. 

Dany's PCBs:
PAD (2 wires)
PAT (3 wires)  pattern
- OMN PAT 1
- CRD PAT 2
- 8 - PAT 3
LC (2 wires) low cut
RBK - Rear Backplate
RD  - Rear Diaphragm
FBK - Front Backplate
FD - Front Diaphragm

Can someone help me make sense out of how to hook them up? 

This is the portion of the U87Ai schematic that shows the headbasket connections (1-7).

Click to expand...

Vinyalwall I was going to ask for the same kind of help I too am trying to hook up a U87Ai headbasket to this circuit I know that our 87Ai capsules have 3 connections vs 4 on vintage capsules so we wont be able to get all patterns.... I myself only want cardiod anyway.....

So can anyone help us  as I was saying I myself only needs cardiod for my mic I got original schematic & rubbed out connections & components I dont think I need for my cardiod only version can you take a look please big thanks

S-O said:

The polystyrene are available on Dany's page.

Click to expand...

If you think you might get serious about DIY I highly recommend you break down and buy a whole bunch of various values of polystyrenes from JustRadios.com.

I did that, and it's got a minimum $20 buy and a high shipping, but you'll be set and not have to keep ordering onesy-twosey from Dany or others. It's saved my ass a few times because if I damaged one of these little buggers I've got backups - and they are fairly easy to muck up.

Just a thought,

Mike

I was finishing up my mic, and realized my HK87 doesn't fit in the saddle on my capsule mound.  Does anyone have a source of mount or saddle that would work? 

Thanks,
Craig

Did this for Steve O'Boyle of Ugly Amps. Happy to report, it came out perfect, first time! Dany's boards, Chunger's beautiful SYT-5, Eric Heiserman's beautiful capsule, cinemag transformer. How bout' that Altoid Transformer mount, huh, huh? Hard to ship it out, came out so nice. Thanks Dany and Chunger.

Here's a quick audio clip;

https://www.dropbox.com/s/4u23ann438kz0ie/StevesU87iTest%201.wav?dl=0

Looks good.

Sounds good, too.

Sort of like um ...  a U87. 

Help, I finished a U87 build, and the mic has a problem.

Voltage at Drain, is always 23.2v. Adjustments to potentiometer have no effect on drain voltage. It just sits to 23.2v.

Most voltage readings  look normal, with the exception of voltage at 10K resistor (after Zener). It reads 23.32. Voltage at zener is 23.45.

Also, if I check continuity between orange and yellow wires of transformer, DMM rings indicating 35ohm resistance on these two wires. Is this normal?

Thank you very much for you help, and best regards!

HL

What brand of FET are you guys using do they vary.... did I read somewhere only certain brands were good, Texas intruments

Thanks happy builds 

Hey guys. I'm hoping someone can help me trouble shoot my mic. Cardioid works perfect, but Omni and Figure 8 have a bunch of overwhelming white noise. I'm assuming it might be a problem with the switch board or maybe part of the circuit that would be isolated to Omni and Figure 8. But obviously I'm a noob so I'm looking for advice on some troubleshooting I could do with my multimeter to help isolate my issue.

OrganizedKonfusion said:

Hey guys. I'm hoping someone can help me trouble shoot my mic. Cardioid works perfect, but Omni and Figure 8 have a bunch of overwhelming white noise. I'm assuming it might be a problem with the switch board or maybe part of the circuit that would be isolated to Omni and Figure 8. But obviously I'm a noob so I'm looking for advice on some troubleshooting I could do with my multimeter to help isolate my issue.

Click to expand...

If you flip the capsule leads around does the noise follow to the cardioid position or continue to just be in omni/figure 8? Basically try to rule out any potential capsule issue then work downward

-Dave

wave said:

OrganizedKonfusion said:

Hey guys. I'm hoping someone can help me trouble shoot my mic. Cardioid works perfect, but Omni and Figure 8 have a bunch of overwhelming white noise. I'm assuming it might be a problem with the switch board or maybe part of the circuit that would be isolated to Omni and Figure 8. But obviously I'm a noob so I'm looking for advice on some troubleshooting I could do with my multimeter to help isolate my issue.

Click to expand...

If you flip the capsule leads around does the noise follow to the cardioid position or continue to just be in omni/figure 8? Basically try to rule out any potential capsule issue then work downward

-Dave

Click to expand...

Thanks for the response Dave! I'll give that a shot first and then report back. I should have mentioned that all patterns seem to be functional, its just that omni and figure 8 both have really bad noise. Omni is much worse than figure 8. Hopefully its just a bad joint or maybe a bad poly! I'll try switching the capsule leads around soon.