Re: Neumann U87 Vintage Circuit Build Thread
« Reply #140 on: March 29, 2012, 07:38:53 PM »
ok i got it working but the is a low ground loop type hum that changes as you move the mic around near things, it this a grounding issue?  i dont have the case on yet as i would have to shave the side of the pot to fit it.  Where do i start to trouble shoot. 

Thanks Scott





Re: Neumann U87 Vintage Circuit Build Thread
« Reply #141 on: March 29, 2012, 07:43:37 PM »
ok i got it working but the is a low ground loop type hum that changes as you move the mic around near things, it this a grounding issue?  i dont have the case on yet as i would have to shave the side of the pot to fit it.  Where do i start to trouble shoot. 

Thanks Scott

if you dont have the body of the mic you dont have RF isolator , so  that is normal ,  the body and the basket at ground is your protection,

Dan,

Re: Neumann U87 Vintage Circuit Build Thread
« Reply #142 on: March 29, 2012, 08:54:35 PM »
Ok got the body on and everything fits together and works great however when I tighten to much or too little it seems as if the phantom power turns off or gets shorted.  The mic doesn't work at it optimum level.  I think someone wrote about this a way back or on the original thread I will have to got back and trouble shoot this.  Other than that it sounds great.  I will put some sax through it tomorrow and upload some sound clips. 


This thing is awesome thanks alot DAN, you the MAN!!!!!!!!!

Now I must find a cool color does home depot sell Neuman grey? hahahah but in a hammered looked?

Thanks again Dan for everything!!!!!!


-Scott


Will try to get some pics up tonight.

Re: Neumann U87 Vintage Circuit Build Thread
« Reply #143 on: March 29, 2012, 10:42:14 PM »
B1

Re: Neumann U87 Vintage Circuit Build Thread
« Reply #144 on: March 29, 2012, 10:42:59 PM »
B1

Re: Neumann U87 Vintage Circuit Build Thread
« Reply #145 on: March 29, 2012, 10:44:15 PM »
B2

Re: Neumann U87 Vintage Circuit Build Thread
« Reply #146 on: March 29, 2012, 10:46:39 PM »
B2

No Matter which way I wire the LC the switch on the mic is still backwards any ideas?  I just left it off for now its the one with the black electrical tape on it.


Re: Neumann U87 Vintage Circuit Build Thread
« Reply #147 on: March 29, 2012, 11:08:17 PM »
Some Short Demos

Please don't laugh as I kinda rushed to do these.  But this is a project I am working on.  I am still working on mic placement and mixing but this gives you an idea of what the mic sounds like compared to an AKG c414, the older kind from the 90's.  I am running both Mics through Slenderchap's  Eee-Zee 1073 clone.  With just a touch of waves C1 compressor.  And true verb for the mix demos.  Like I said still have a lot to learn and figure out mixing, reverbs and mic placements.  Since I was doing everything myself in different rooms I was running around like crazy so there are a few pitch issues but you get the idea. Be gentle.

U87 Clone Dry

http://www.ehornstudios.com/media/U87%20Clone%20Dry.aif

U87 Clone Mix

http://www.ehornstudios.com/media/U87%20Clone%20Mix.aif

C414 Dry

http://www.ehornstudios.com/media/C414%20Dry.aif

C414  Mix

http://www.ehornstudios.com/media/C414%20Mix.aif

Let me know what you think of the U87.  I already have some conclusions.



HellfireStudios

Re: Neumann U87 Vintage Circuit Build Thread
« Reply #149 on: March 30, 2012, 10:52:37 AM »
Fair warning: If you are using the aurycle mic bodies (or prob many others) do NOT store the microphone in the box it came in. I opened up one of mine to enact a quick repair and the capsule was already thoroughly covered in foam dust. Luckily most of it came off with some careful and distant use of canned air, but there's still more than I'd like. Stupid foam...

This seems to be a common trait with foam-shocked boxes and flightcases. The capsules's polarization will actually electrically attract the broken-off foam bits to the diaphram. Although the logic behind using a material that both protects and damages a mic at the same time is beyond me, you can take preventative measures against it's detrimental effects. Simplest option would be the plastic bag your mic, hopefully, came in (or another similar-sized bag). Fancier, and more expensive, options are cloth-based bags (velvet looks great) or a whole seperate velvet-lined box that goes inside the flightcase (this seems to be a popular option in the expensive mic world). You could also wrap the foam from the box (the mic came in) in velvet and use the box as you did before.

I think I've spent enough time off topic. On with building...
"Tommorrow is just yesterday in reverse. Just like friends are enemies in reverse." -Gary Busey


Marcocet

Re: Neumann U87 Vintage Circuit Build Thread
« Reply #150 on: March 30, 2012, 03:28:31 PM »
Ok got the body on and everything fits together and works great however when I tighten to much or too little it seems as if the phantom power turns off or gets shorted.  The mic doesn't work at it optimum level.  I think someone wrote about this a way back or on the original thread I will have to got back and trouble shoot this. 

I had the same problem and it turned out to be something intermittent in the low cut switch assembly. When the switch was pushed up towards the capsule it would somehow turn off the mic. Must have been a short, but before I could locate it any more specifically it fixed itself. It's been working fine since then.


Re: Neumann U87 Vintage Circuit Build Thread
« Reply #151 on: March 30, 2012, 04:29:55 PM »
sax-
 personally i think the 414 sits better in that mix, the u87 makes it stick out a little odd. but stand alone i prefer the u87.
Adam
only got here by owning a soldering iron and bad life decisions.

Re: Neumann U87 Vintage Circuit Build Thread
« Reply #152 on: March 30, 2012, 06:36:30 PM »
Hey Saxmonster i am not sure about the mix since i am not a mix guru but when i hear the sounds of the U1621 i really have the impression that i am in the room with you  8)

cheers ,

dan,
 

kante1603

Re: Neumann U87 Vintage Circuit Build Thread
« Reply #153 on: March 30, 2012, 07:11:13 PM »
B2

No Matter which way I wire the LC the switch on the mic is still backwards any ideas?  I just left it off for now its the one with the black electrical tape on it.
@saxmonster:

Hi,

do you mean the lc function is set to "off" when switched to "in" and vice versa?
Please do a continuity check:Switch to "in" and look if your (now or still) loose wires do have continuity or not.
I can not see exactly the wiring directly on the switch in your photo,but I guess it´s just open condition then.
If so you can swap the outer (white?) wire on the switch(!) to the opposite side to get a "closed" condition.
The running order of the wires connected on the pcb doesn´t matter;It´s just a matter of the switch being closed or open.
Don´t know this specific switch,but I bet it´s just that simple.

Hope to have helped,

Udo.

Re: Neumann U87 Vintage Circuit Build Thread
« Reply #154 on: March 30, 2012, 07:47:57 PM »
Kante
That's what it was I pulled the white wire off of the switch and put it on the other side of the red one and now it works.  Fine.

kante1603

Re: Neumann U87 Vintage Circuit Build Thread
« Reply #155 on: March 30, 2012, 08:01:54 PM »
Cool,nice to hear,have fun,

Udo. ;)

Hank Dussen

Re: Neumann U87 Vintage Circuit Build Thread
« Reply #156 on: March 31, 2012, 06:53:47 AM »
Anybody here has been able to contact AMI Tab Funkenwerk here?
From my regular mail account all my mails were returned as spam.
And they didn't respond to my Gmail account...


wthrelfall

Re: Neumann U87 Vintage Circuit Build Thread
« Reply #158 on: March 31, 2012, 08:51:17 AM »
I've got the use of a 'scope so decided to calibrate the FET according to Matador's post.  Problem is, when I measure the signal on the drain of the FET, the waveform doesn't really resemble a sine wave anymore, and doesn't respond to R11 calibration the way it should (ie. with the waveform flattening out as amplitude is increased).  I checked my sine wave source on the scope and it's perfectly symmetrical and normal.  Attached is a photo of the waveform I get at the FET drain.

wtmnmf

Re: Neumann U87 Vintage Circuit Build Thread
« Reply #159 on: March 31, 2012, 08:53:08 AM »
Anybody here has been able to contact AMI Tab Funkenwerk here?
From my regular mail account all my mails were returned as spam.
And they didn't respond to my Gmail account...

They had a problem with their host.   Should be fixed now.


 

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