Neumann Vintage U87 Clone : Build Thread.

[JessJackson]

Ok, testing my 3 FET's with 9v battery

IDSS Results are

1 - 4.4
2 - 10.4
3 - 16.2

Which one should I use?

 

[HellfireStudios]

10.4 seems to be closest to ideal. You'll get a bit more gain, but less headroom from the 4.4, and the opposite is true for the 16.2 IDss FET.

-James-

 

[Volume11]

I just finished my build and I have a slight problem, as usual. The front of the capsule works, but the back is very quiet, almost non existent, in all modes. I broke a screw off inside the outer shell of the back of the capsule, and I have a bad feeling that this might be the reason. I didnt cut the screw short enough and it hit something on the inside of the capsule. The head of the screw broke off so easily, believe it or not. I'm hoping that the problem lies elsewhere. Did anyone else have this issue?

 

[poctop]

I just finished my build and I have a slight problem, as usual. The front of the capsule works, but the back is very quiet, almost non existent, in all modes. I broke a screw off inside the outer shell of the back of the capsule, and I have a bad feeling that this might be the reason. I didnt cut the screw short enough and it hit something on the inside of the capsule. The head of the screw broke off so easily, believe it or not. I'm hoping that the problem lies elsewhere. Did anyone else have this issue?

Have a look on page 1 of the thread there is picture on how to correctly connect the capsule ,

Let me know if this helps,
Best,
Dan,

 

[Volume11]

I just finished my build and I have a slight problem, as usual. The front of the capsule works, but the back is very quiet, almost non existent, in all modes. I broke a screw off inside the outer shell of the back of the capsule, and I have a bad feeling that this might be the reason. I didnt cut the screw short enough and it hit something on the inside of the capsule. The head of the screw broke off so easily, believe it or not. I'm hoping that the problem lies elsewhere. Did anyone else have this issue?

Have a look on page 1 of the thread there is picture on how to correctly connect the capsule ,

Let me know if this helps,
Best,
Dan,

I mounted  the capsule exactly like the drawing, using the sides of the capsule. I noticed in one picture, that one of the body connections is mounts to the front side of the capsule, along the outer ring. Is this necessary, or will it have the same effect as mounting the lead to the side of the capsule?

 

[HellfireStudios]

I just finished my build and I have a slight problem, as usual. The front of the capsule works, but the back is very quiet, almost non existent, in all modes. I broke a screw off inside the outer shell of the back of the capsule, and I have a bad feeling that this might be the reason. I didnt cut the screw short enough and it hit something on the inside of the capsule. The head of the screw broke off so easily, believe it or not. I'm hoping that the problem lies elsewhere. Did anyone else have this issue?

Have a look on page 1 of the thread there is picture on how to correctly connect the capsule ,

Let me know if this helps,
Best,
Dan,

I mounted  the capsule exactly like the drawing, using the sides of the capsule. I noticed in one picture, that one of the body connections is mounts to the front side of the capsule, along the outer ring. Is this necessary, or will it have the same effect as mounting the lead to the side of the capsule?

Which capsule are you using?

 

[Volume11]

Beesneez k8

 

[fsalter]

I just tested mu U87 clone, and i must say Dan, that it sounds stellar. In fact better than a vintage U87 i used a while ago. Thanks a lot for your hard work, and especially for taking the time to help me out allowing me to go to your place and fix my little but persistent problem. I will probably tackle the D47 next. Rock on!

 

[poctop]

Beesneez k8

can you send a picture of your section ,  are the backplate on this capsule short togheter or open as it would be supposed to be ,
just checkin,

where did you connect the capsule pad and all that,
D

 

[Volume11]

Beesneez k8

can you send a picture of your section ,  are the backplate on this capsule short togheter or open as it would be supposed to be ,
just checkin,

where did you connect the capsule pad and all that,
D

Hey Dany, I really appreciate all of your help. I'll snag the mic from the studio tonight, and I should have some pics up by tomorrow. I can't say for sure that they are shorted together or not, but I will check for continuity.

Thanks again,
Chad

 

[TheGuitarist]

Bit late but here are some snaps... i found that i had one of my tantalum caps (c8) reversed!!! Which i felt VERY foolish about (forgot that they marked the positive not the negative....) and replaced it with a lytic cap... but still the same problem.

http://imageshack.us/a/img35/7746/dsc00666jq.jpg
http://imageshack.us/a/img594/4024/dsc00665s.jpg
http://imageshack.us/a/img841/9079/dsc00664ut.jpg
http://imageshack.us/a/img17/8774/dsc00663td.jpg

lemme know if you need anything else!

Excuse the messyness, i didn't want to heatshrink everything until i know it was working.

 

[poctop]

the first thing i see is that you should have used the square pcb  , but that wont prevent it to work,

i notice your transformer is not connected properly 1-2 should be a pair of the same color,  3-4 also,

at this moment if you dont have the voltage right ,  i would step backward remove capsule connection, wiring LC, PAD , the fet ,  and finally the transformer ,

and check for basic voltage again , replace the zener , and check for cold solder and shorts trough cap and resistor,

something is leaking current from your setup ,  you cannot get this one working unless you have 24 V up the zener,

hope this helps,

 

[TheGuitarist]

I had a similar issue to chunger in his blog with my wires being reversed, unless his conclusions were wrong? Removing cap was first thing i tried but i'll try the pad xformer etc.

 

[poctop]

Measure the resistance in ohm between black pair , and then the yellow pair , 

the higer reading will go to pin RT, SW  or 1-2
the lower reading goes BL, WS, or 3-4

I attached a picture of the suspicious connection.

this is a different issue here,
hope this helps,
Dan,

 

[Toure14]

Hey Dany is it possible to install these type of switches on chungers SYT-5 mic body instead of the 3 metal flip switches? if so where would you recommend finding them?


http://microphone-parts.com/wp-content/uploads/2012/09/body_front.jpg

 

[TheGuitarist]

Dan,

I feel like an idiot with the xformer now... that was the voltage issue the whole time. One mic working beautifully!!

The other mic... mostly, it works in cardioid perfectly... omni, t takes a few seconds to... for lack of a better word... charge up... it takes a bit to get to a proper level...

Figure 8 works at very low level.

Thanks so much for all the help so far!!

 

[poctop]

you might be able to trace down the problem with the other mic with the working mic comparing them togheter as how the capsule is wired and all that.

Probalby a capsule wiring issue there ,

it is normal for the mic when you change pattern that it will take a second or 2 to charge the capsule and polarize the different pattern ,

BEst,
Dan,

 

[Volume11]

Beesneez k8

can you send a picture of your section ,  are the backplate on this capsule short together or open as it would be supposed to be ,
just checkin,

where did you connect the capsule pad and all that,
D

If you look at this first image, which is the front of the capsule, you can see the hole with the broken screw in it, just left of the black lead.

Backside of the capsule..

I measured the resistance between the two outer screws (black leads on the sides of the capsule) and its only 1.7 ohms, which also means that there continuity between the two. I tested this while the capsule was in circuit, in cardiod. Could this be a problem?

thanks,
Chad

 

[poctop]

Yes,  remove capsule to make sure,  and measure resistance between the 2 backplate if it is short the pattern will not work,

not sure if your capsule is the proper one or might have been an error with the fabrication  ?

the capsule needs to isolated backplate ask your vendor

LEt us know,
Dan,

 

[Volume11]

same result with the leads disconnected, i still get continuity. I may have messed it up after all. I'll report back once I hear from Beesneez.
Thanks