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

[tskguy]

The exceptions are the holes you actually dont solder to. If you follow Poc's pictures it will be more clear. The leads of thos components are only solderd to one side. Or none at all. Its for the Hi z section.

Eric

 

[Volume11]

Hey tskguy, do you mind helping me with my question a couple posts back? I have my psu almost completely finished, I'm just unsure of the 20v transformer , and led wiring.

 

[tskguy]

mmm its the square one right? If so there are 5 tabs 3 on top and 2 on the bottom. The 2 on the bottom go to your switch and power inlet. Its the same connections as the other transformer. So power switch on sends AC to both TX's
The outer 2 tabs on the top go to the pcb. Again study the pictures in Poctops build docs. With this info it should be more clear.

Eric ;D

 

[Volume11]

Yeah the square one. I have the top connections correct, going to the pcb, but the bottom ones I am confused about. Do they both go to the switch, or does one go to the switch and the other to the neutral on the iec plug? I tried to look at all of Danny's pic and your pics and I can't see this part of the psu on any of them. I looked over the schematic several times but I only understand the secondary side of it, unfortunately. I am also unsure where to connect the positive lead of my LEDs. Thanks for your response 

 

[tskguy]

Ok so first off be carefule!! there is 200volts in this PS and it can kill you! Both transformers are connected the same way.  So both tx's have a pimary wire conected to one of the hot iec connections (not the earth) the other primary wire for both tx's goes to one leg of the power switch. then the power switch open leg goes to the open hot iec conection. PCB and Earth go to start ground.(connected to chassis) I attached a very crude drawing hope it clears it up for you.

 

[Volume11]

Ok, so I have tab 2 on the transformer going to the switch and  tab 3 going to the neutral on the input.  I get a 20v reading between 5 and 8 on the small transformer, but I am getting a reading in the 300s between the yellow and black output wires on the big transformer that are going to the 210v pcb section ???

 

[Volume11]

Ok so first off be carefule!! there is 200volts in this PS and it can kill you! Both transformers are connected the same way.  So both tx's have a pimary wire conected to one of the hot iec connections (not the earth) the other primary wire for both tx's goes to one leg of the power switch. then the power switch open leg goes to the open hot iec conection. PCB and Earth go to start ground.(connected to chassis) I attached a very crude drawing hope it clears it up for you.

Aaah, I almost have it exactly like this. I have 2 and 3 reversed on the small transformer. Should I change them, or does this have the same effect? Thanks for drawing this up, I really appreciate it

 

[tskguy]

I am not sure what you mean by 2 and 3? Are you referring to the primary? That’s the bottom 2 connections on the small square TX. Those don’t matter, the 2 wires connected on the top need to be the outer 2 connections and either can be connected to the pcb.

And I forgot to mention that I wouldn’t use a led...I am using a 120 v lamp right off the IEC and switch.

 

[Volume11]

I am not sure what you mean by 2 and 3? Are you referring to the primary? That’s the bottom 2 connections on the small square TX. Those don’t matter, the 2 wires connected on the top need to be the outer 2 connections and either can be connected to the pcb.

And I forgot to mention that I wouldn’t use a led...I am using a 120 v lamp right off the IEC and switch.

Ok, that's kind of what I figured. Thanks for the tip on the light, and for all of your help  :

 

[tskguy]

Glad to help out
;D
Eric

 

[poctop]

Curious about your  "EXCEPTION 1" pic. What am I missing?                                                       

The Exception picture is actually the component you have to take care in the second step of the build so basically all of those exception will have a link to another component via a flotating connection , so it reminds you not to cut the lead from those until you actually use them in the HZ bridge,
hope this helps,
dan,

 

[JessJackson]

an interesting mod I came across.

http://repforums.prosoundweb.com/index.php/topic,36020.0.html

 

[wave]

Jess,

That looks great. I'm planning on getting a powder coating gun to do mine.

Haven't ordered my body yet, think a Binder 7 pin connector will fit?

Dylan,
Implementing a Binder will require a considerable modification to the bottom of the mic. You will probably not be able to use a screw on type shockmount either. It's for this reason that we are using the Amphenol 7 pin connectors. they drop in the bottom with minor boring and give you the ability to use a screw on Amphenol female cable end as well as a screw on shockmount.

Dave

p.s. AMI version build manual coming soon complete with pics of how to use the Amphenol end. Stay tuned

 

[burglar]

p.s. AMI version build manual coming soon complete with pics of how to use the Amphenol end. Stay tuned

Looking forward to it.  Will it include a step by step build manual for the PSU?

 

[wave]

Yes
We will have instructions for the PSU

Dave

 

[Volume11]

Dylan,
Implementing a Binder will require a considerable modification to the bottom of the mic. You will probably not be able to use a screw on type shockmount either. It's for this reason that we are using the Amphenol 7 pin connectors. they drop in the bottom with minor boring and give you the ability to use a screw on Amphenol female cable end as well as a screw on shockmount.

Dave

p.s. AMI version build manual coming soon complete with pics of how to use the Amphenol end. Stay tuned

Why would you use a screw on shockmount? Are you referring to ChuckD's U67/87 body? Is the amphenol connector a screw on type, or is it more like the neutrik type?

 

[tskguy]

Here is a pic of  what Wave is talking about.

 

[burglar]

Not sure if they're of any value to anyone but I have a NOS Haltron EF86 & a used Philips Miniwat EF86.  No idea what they're worth.  Probably not a lot.  My grandad has a huge collection of old tubes and having shown him Poctops white market thread he managed to dig these out along with 2 old EF86 mullards. 

 

[Volume11]

Here is a pic of  what Wave is talking about.

Aw damn, I jumped the gun on this build. It would be a total pain for me to go back and redo my cable and mic jack. Looking forward to the build instructions though. Will they include the calibration part of the build?  That would be great, since it's my next step.  ;D

 

[poctop]

Here is a pic of  what Wave is talking about.

Aw damn, I jumped the gun on this build. It would be a total pain for me to go back and redo my cable and mic jack. Looking forward to the build instructions though. Will they include the calibration part of the build?  That would be great, since it's my next step.  ;D

Please note that this modifcation is not needed ,  the U67 mic body is supplied with a 7 pin connector,
the modification is needed if you prefer a Tuchel connector version ,
this is just to clear up some confusion ,
cheers,
Dan,