Neumann U67 Clone : D-U67 Tube Microphone Build Thread.

[sage]

Thank you - sounds like the 87 could be a good start for a pair of Room mics for Drums -
I think it might be a bit easier too as a first mic projects  -

Thank you for the suggestion -

sage

 

[dmp]

Wave,
The sample you posted sounds GREAT!
You channel the Beatles very well.

I think the sound of my mic is off. It sounds muffled and isn't crisp like I expect.

The majority of the mic's sound is capsule related.

I have a beezneez capsule in it so that sound be good?

Any test ideas?

- Dan

 

[wave]

Dan
Thanks for the kind words. The mic should def not sound muffled. The beezneez capsule should sound great (esp if it's the brass K67 remake). Can you post some pics of the internals so we can take a look?

Dave

 

[dmp]

I'll try to post some pictures.
It is the brass beezneez

 

[dmp]

Here are some quick pics - without disassembling it is pretty hard to get all the detail.

 

[dmp]

another shot

 

[dmp]

last one

 

[wave]

Thanks for the pics.
Could you take one of the HiZ area (under the switchboard from both sides)
Also, what kind of tube are you using? Have you swapped a different one in there or do you just have the one?

Thanks,
Dave

 

[dmp]

I have other tubes. I can swap it with the one in my G7 to be sure it is good.

I'll have to take it apart to get a better pic of the HiZ area. Probably not until this weekend...

Thanks!

 

[wave]

Try the tube swap as it's easy. Report back

Dave

 

[Winetree]

Got my bodies (today), Beesnez Brass capsules, BV-12 Transformers,
Mouser BOM parts, and a bag of polys all together.
Getting back to the build so I went through the 12 page post.
What poly goes in C1?
Thanks

 

[wave]

It looks like a .01µF goes in C1 and I don't think it's a styrene.

Dave

 

[Winetree]

In the intro post it reads•1X FeedBack Cap (80-160pf) styroflex/630V

--------------------------------------------------------------------------------
What value is used?
In the pictures it looks like it's in C1 a poly (to the right of the 3 red Wimas)

 

[dmp]

In the intro post it reads•1X FeedBack Cap (80-160pf) styroflex/630V

--------------------------------------------------------------------------------
What value is used?

I think that one is C17. 

 

[poctop]

In the intro post it reads•1X FeedBack Cap (80-160pf) styroflex/630V

--------------------------------------------------------------------------------
What value is used?
In the pictures it looks like it's in C1 a poly (to the right of the 3 red Wimas)

The original BOM implies a 100pf or stick in the middle and you will be fine ,

indeed Feedback cap is C17
D.

 

[wave]

Dany is correct (as usual). Eric and I used 100pF for our mics and they seem to be right to me. You can play with this value to kind of "tune" the mic to your tastes.

Dave

 

[dmp]

So I went over the mic again - comparing to the schematic and everything looks good (except on the original schematic the HPF filter cap is 500pf?)
With a friend tested the mic some more last night. It sounded fantastic! I think I was out of it when I tried it earlier this week.
Whoo hoo!
Very different than my C12, but both are great.

 

[Jim50hertz]

Ah excellent! Glad it worked out.  I had a similar experience with my MK47, built it up and tested it (worked right off the bat, no trouble shooting) and thought it sounded congested and woofy.  Fresh ears and using it on a few different sources turned me around.  Great mic.  Looking forward to finishing these DU67s up when I release some funds for a mouser order.

Enjoy yours 

 

[wave]

So I went over the mic again - comparing to the schematic and everything looks good (except on the original schematic the HPF filter cap is 500pf?)
With a friend tested the mic some more last night. It sounded fantastic! I think I was out of it when I tried it earlier this week.
Whoo hoo!
Very different than my C12, but both are great.

Hi Dan,
Any chance you could post up some sound samples and tell us the signal chain you use to record them?

Thanks,
Dave

 

[poctop]

Important Notice For D-U67 polarity

I have been checking polarity of each 87-47F-67,  and i have found that the initial statement from ktfstudio was right, i did confused Tuchel pin 1 and Switchcraft pin2 ,  as the schematic underlay would point to.  So Since old Tuchel Pin 1 is +  and old Tuchel pin 2 is -  then only the D-U67 mic would have reversed polarity.  this would not be noticeable with the use on the single mic but when used in pair with other microphone this will matter enourmously.

please Let me know if i got this Stament Wrong.

So Since old Tuchel Pin 1 is +  and old Tuchel pin 2 is -

The Easy FiX :  swap pin 2 and pin 3 on xlr output connector in the power supply. 

Thanks For catching this ktfstudio. 

Best,
Dan,