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

[kpearsall]

Next thursday is the test. The only time we can get together unfortunately. It was postponed due to the u67 owner being out of town.

 

[poctop]

Next thursday is the test. The only time we can get together unfortunately. It was postponed due to the u67 owner being out of town.

Thanks Ken ,  My popcorn will be ready then 
Best,
DAn,

 

[Volume11]

hey guys, I am just about finished with my build here, but I have ran into a little speed bump. I am assuming that the middle lead of the 3 way switch, goes to the front of the capsule, but I can't verify this for sure on the schematic. It shows the middle lead omni, (which is actually labelled figure 8 on my mic), connects to nothing.  I have the ring of the capsule connected to the post on the left side of the tube pcb, which connects to the pad switch. This looks correct to me on the schematic.I'm also assuming that the back plate of the capsule goes to the right post of the tube pcb, which connects to the omni side of the 3 way switch. I am still learning how to correctly read schematics, so I didnt want to continue without verifying these connections.

Another problem I have is, that when I go to mount my Beesneez capsule to either the mount that it came with, or the mount that came with the body, the holes don't line up. I ended up just using one screw. Is this something that anyone else has had an issue with?

Any help is greatly appreciated.


Edit... Now after looking at the schematic and thinking it over a little more, I am thinking the opposite. The back capsule being connected to the 3 way switch in cardiod, turns it off, right?  :-[

 

[micaddict]

It shows the middle lead omni, (which is actually labelled figure 8 on my mic), connects to nothing.

No solution from me, but a possible reason for confusion.
Do you have the earlier SYT-5 body, from ChuckD? If I'm not mistaken, that one indeed has figure eight in the middle.
The ones from chunger have cardioid in the middle position.

 

[poctop]

It shows the middle lead omni, (which is actually labelled figure 8 on my mic), connects to nothing.

No solution from me, but a possible reason for confusion.
Do you have the earlier SYT-5 body, from ChuckD? If I'm not mistaken, that one indeed has figure eight in the middle.
The ones from chunger have cardioid in the middle position.

If you look at the second part of the m269b build there is a whole pictorial in this section to proper wire the u67 , it is the same except one step wich is clearly noted
Have a look and let me know
Best dan

 

[micaddict]

http://www.groupdiy.com/index.php?topic=51350.0 

But FWIW, aren't there two versions of the SYT-5?

 

[Volume11]

awesome, got it! now with my psu calibration, I am having an issue measuring the B+. I measure it to any ground right? I easily get 6.3v to the heater. When I measure the "AC in", I get 173v instead of 210v. Thats probably not going to cut it right? I'm so close!

 

[Volume11]

awesome, got it! now with my psu calibration, I am having an issue measuring the B+. I measure it to any ground right? I easily get 6.3v to the heater. When I measure the "AC in", I get 173v instead of 210v. Thats probably not going to cut it right? I'm so close!

Turns out that the orange and red wires from the xfmr werent tied together, when i thought that they were. I now get 228v at B+. Can someone please tell me if this will be close enough? I have the trim pot completely cranked.

 

[Volume11]

It shows the middle lead omni, (which is actually labelled figure 8 on my mic), connects to nothing.

No solution from me, but a possible reason for confusion.
Do you have the earlier SYT-5 body, from ChuckD? If I'm not mistaken, that one indeed has figure eight in the middle.
The ones from chunger have cardioid in the middle position.

Yeah, I have the earlier ones from Chuck. So, I guess it wont be perfect, but close enough for me.

 

[poctop]

awesome, got it! now with my psu calibration, I am having an issue measuring the B+. I measure it to any ground right? I easily get 6.3v to the heater. When I measure the "AC in", I get 173v instead of 210v. Thats probably not going to cut it right? I'm so close!

Turns out that the orange and red wires from the xfmr werent tied together, when i thought that they were. I now get 228v at B+. Can someone please tell me if this will be close enough? I have the trim pot completely cranked.

Have you installed the external series resitor of 56K ish to the B+ trim as in the build picture page 1 of this thread
Let. Me know
Dany

 

[Volume11]

Hi Dany, yeah I did. I get 228v unloaded, and about 180v loaded.

 

[poctop]

Hi Dany, yeah I did. I get 228v unloaded, and about 180v loaded.

You need 210 loaded can you reach that
Dan

 

[janps]

YES IT'S DONE. my 2 U67 clones are  now finished and tested, they are sounding amazing and I want to thanks a lot Mr procop for this excellent project as Eric (TSKGUY) that made very nice american capsules, I build mine with AMI transformers ; congratulations to all of you for making this project possible.
All the best.
PS I will try to join something to ear and see (I have the nice PSU cases from Dan , very nice too)
Jean-pierre

 

[micaddict]

they are sounding amazing

Hearing is believing. 

 

[Volume11]

Hi Dany, yeah I did. I get 228v unloaded, and about 180v loaded.

You need 210 loaded can you reach that
Dan

228v was as low as i could get once it was loaded. Should I add a larger resistor, or do you think that there may be an error in my build?

thanks for the responses

 

[poctop]

Hi Dany, yeah I did. I get 228v unloaded, and about 180v loaded.

You need 210 loaded can you reach that
Dan

228v was as low as i could get once it was loaded. Should I add a larger resistor, or do you think that there may be an error in my build?

thanks for the responses

could you show us a picture of your psu build,  did you check that you wired your the external resistance in series with the pot or in parralle ,  tis may be some high tolerance on the pot doing that along with the resistance ,    if you measure the voltage and then connect the mic is the voltage dropping ? in a sense is your tube drawing B+ plate current if so it shoud drop on power on ,  if everything is wired and installed properly you may fix the problem using a larger resistor ,

if you figures that it is consumming 0.8ma you can then calculate the extra resistive path to put it dow by arround 20V
= around and extra 20K .

Hope this helps,
dan,

 

[Volume11]

Hi Dany, yeah I did. I get 228v unloaded, and about 180v loaded.

You need 210 loaded can you reach that
Dan

228v was as low as i could get once it was loaded. Should I add a larger resistor, or do you think that there may be an error in my build?

thanks for the responses

could you show us a picture of your psu build,  did you check that you wired your the external resistance in series with the pot or in parralle ,  tis may be some high tolerance on the pot doing that along with the resistance ,    if you measure the voltage and then connect the mic is the voltage dropping ? in a sense is your tube drawing B+ plate current if so it shoud drop on power on ,  if everything is wired and installed properly you may fix the problem using a larger resistor ,

if you figures that it is consumming 0.8ma you can then calculate the extra resistive path to put it dow by arround 20V
= around and extra 20K .

Hope this helps,
dan,

I'm sorry I didn't get back to you on this sooner. I read your last post wrong and was thinking of unloaded instead of loaded, so I was able to get the voltage up to 210v loaded. The mic sounds excellent! I used the beesneez capsule with an ami xfmr. I only had time to test it on speech and a little bit of electric guitar. I'll report back when I get some more time with it.

Thanks for this project!

 

[0dbfs]

Hey Guys, I am building four of these.... Well, I'll be doing two m269's and two 67's. I've got 2x each of Max's and AMI's trafo's and four bodies plus a bunch of parts ready...

I do have 2x of Eric's K67 capsules which I'll build into each a 67 and 269 using the different trafo's.

I'm wondering whether anyone has done either of these with Eric's capsules and/or the BeezKneez K6. Not looking for one to be "better" than the other but am looking for a range of sonic options in the same flavour. I'm sure Ben's K6 will be wonderful but was looking for any observations and any other options for high quality k67 style capsules.

In any case thanks in advance for the input and I'm happy to share my thoughts and results as I put these together.

Ciao,
jb

 

[micaddict]

I do have 2x of Eric's K67 capsules which I'll build into each a 67 and 269 using the different trafo's.

For comparison sake, best would be to have four of Eric's capsules, one D-67 with AMI tranny, one with ioaudio tranny, one D-269 with AMI tranny and one with ioaudio tranny. That's four different combos, but with "the same" capsule. Interesting for your fellow GroupDIY members. 

But I have a feeling you prefer to have two pairs that can do stereo.
In that case, get two BeesNeez K6s.

 

[saint gillis]

Hi everybody, thanx for this wonderful thread, I ve just finished my mic with tskguy's capsule & AMI T67 transformer, sounds great!
Just to say that 11mm 0.01µ caps weren't available on Mouser http://fr.mouser.com/Search/ProductDetail.aspx?R=MKT1813310404virtualkey61310000virtualkey75-MKT1813310404 but I did it with thoose 16.5mm http://fr.mouser.com/Search/ProductDetail.aspx?R=150103J400BBvirtualkey53900000virtualkey539-150103J400BB
It fits Chunger's body without any problem!