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

[mrerdat]

Did you attach the shield of the multi-wire cable between XLR7 and XLR3 to ground? Hard to see from your pic.

Yes.  I'm following the wiring chart so the short run of cable inside the PSU has the black wire connected to pin 3 of the XLR7 (which after the connector now carries the shield signal from the long cable) and is soldered directly to pin 1 of the XLR3 connector.

Also just in case, double-check the XLR7 and XLR3 connectors themselves to see if they're properly grounded (worth re-checking all metal to metal contacts are good). Then see if you get a constant ground from the XL3 casing to the GND pin on the IEC, and same to the headbasket of the mic etc.

All continuity checks out fine.

 

[Banzai]

This part is unrelated to the wiring scheme: the short run of cable you have inside your PSU has its own shield. You want to connect this somewhere on the chassis (on one side only), otherwise it's just a loose antenna and the wires inside aren't shielded. Won't solve your problem, but good practice to tie up all loose ends.

Yes.  I'm following the wiring chart so the short run of cable inside the PSU has the black wire connected to pin 3 of the XLR7 (which after the connector now carries the shield signal from the long cable) and is soldered directly to pin 1 of the XLR3 connector.

 

[poctop]

Hi All, I have been working With Dave at Cinemag For about a year now and Dave Came up with this awesome little new Toy ,

I Proudly Present the CM-15701 in other word the Cinemag (BV-12), I have just tested compatibility with my kits and it can be easily mounted on the bottom bell  8) and leave enough room for the Tube  8) this transformer is compatible with the External Transformer Version of the D-67 Kit available here
www.vintagemicrophonepcbit.com

you can contact Dave here http://www.cinemag.biz/

Here is a little Mounting Demo Proposition .

Best,
Dan,
www.vintagemicrophonepcbkit.com

 

[Jim50hertz]

Price?

 

[poctop]

Hi All, I have been working With Dave at Cinemag For about a year now and Dave Came up with this awesome little new Toy ,

I Proudly Present the CM-15701 in other word the Cinemag (BV-12), I have just tested compatibility with my kits and it can be easily mounted on the bottom bell  8) and leave enough room for the Tube  8) this transformer is compatible with the External Transformer Version of the D-67 Kit available here
www.vintagemicrophonepcbit.com

you can contact Dave here http://www.cinemag.biz/

Here is a little Mounting Demo Proposition .

Best,
Dan,
www.vintagemicrophonepcbkit.com

Not sure yet about the price of the Cinemag BV12 , I will try and ask Dave ,
and report back ,
Best,
Dan,

 

[jandoste]

Hi Dan,
I already bought this tranx http://www.mouser.fr/ProductDetail/Hammond-Manufacturing/186B20/?qs=CoAU%2fpHVZXz4H1LQS1Hn0w%3d%3d and I'm in Europe so do you think it'll work or I have to get new one?

Thanks

Jandoste

 

[poctop]

Hi Dan,
I already bought this tranx http://www.mouser.fr/ProductDetail/Hammond-Manufacturing/186B20/?qs=CoAU%2fpHVZXz4H1LQS1Hn0w%3d%3d and I'm in Europe so do you think it'll work or I have to get new one?

Thanks

Jandoste

yes it will work as this one is a dual primary  so you need to wire the primary in series for 230VAC country ,
Best,
Dan,

 

[jandoste]

Thanks Dan,
This tranx makes me scared... can you tell me please which pins have to wire for 230VAC? I'm asking that because I had a bad story with a tranx

Thank you

Jandoste

Hi Dan,
I already bought this tranx http://www.mouser.fr/ProductDetail/Hammond-Manufacturing/186B20/?qs=CoAU%2fpHVZXz4H1LQS1Hn0w%3d%3d and I'm in Europe so do you think it'll work or I have to get new one?

Thanks

Jandoste

yes it will work as this one is a dual primary  so you need to wire the primary in series for 230VAC country ,
Best,
Dan,

 

[poctop]

For 120V country

For 230V Country

PSU Schematic
https://cdn.groupbuilder.com/groupdiy/u/39511/58d0281994779.pdf

Hop this helps,
Dan,

 

[poctop]

Hi all, I am posting link to Build Tutorial ,

it is also found on vintagemicrophonepcbkit.com on the D67 Page

Microphone assembly

https://cdn.groupbuilder.com/groupdiy/u/39511/58d1402a0351f.pdf

PSU tips and Assembly
https://cdn.groupbuilder.com/groupdiy/u/39511/58d028199482b.pdf

Best,
Dan,

 

[Arkenberg]

Ok guys I am new to this building of a tube circuit. I have been researching as much as possible on what tubes to buy and what to look for in tubes. I know I want telefunken ef86/ef806s tubes but I am not sure what qualifies them as low noise so they can be used in a microphone circuit. Can anyone help me with this please and thank you.

 

[Bowie]

Ok guys I am new to this building of a tube circuit. I have been researching as much as possible on what tubes to buy and what to look for in tubes. I know I want telefunken ef86/ef806s tubes but I am not sure what qualifies them as low noise so they can be used in a microphone circuit. Can anyone help me with this please and thank you.

Nothing really qualifies them as low noise other than listening to them in the circuit.  Tubes like the EF806s, 6072s, etc are designed for low noise but that really means little because the noise levels vary wildly from tube to tube no matter how they test in other areas.  What might be quiet in a mic may not be quiet in a Vox AC15, and vice versa.  A word of caution; these days it seems that most of the "NOS" Telefunken EF86/EF806s you'll see out there have been pulled form old equipment and re-boxed as "NOS".  It's entirely possible to find NOS tubes in unused, surplus equipment but most testers rate EF86s too high.  So, a heavily used and noisy one may actually test "like new".  The market has gotten ugly because there's such high demand for these tubes.

 

[Arkenberg]

Ok guys I am new to this building of a tube circuit. I have been researching as much as possible on what tubes to buy and what to look for in tubes. I know I want telefunken ef86/ef806s tubes but I am not sure what qualifies them as low noise so they can be used in a microphone circuit. Can anyone help me with this please and thank you.

Nothing really qualifies them as low noise other than listening to them in the circuit.  Tubes like the EF806s, 6072s, etc are designed for low noise but that really means little because the noise levels vary wildly from tube to tube no matter how they test in other areas.  What might be quiet in a mic may not be quiet in a Vox AC15, and vice versa.  A word of caution; these days it seems that most of the "NOS" Telefunken EF86/EF806s you'll see out there have been pulled form old equipment and re-boxed as "NOS".  It's entirely possible to find NOS tubes in unused, surplus equipment but most testers rate EF86s too high.  So, a heavily used and noisy one may actually test "like new".  The market has gotten ugly because there's such high demand for these tubes.

Well that sucks! Guess I have just buy and see what I get.
Thanks for the info, if have any other ways to possibly get these tunes please let me know. This would be greatly appreciated.

Jon

 

[gyraf]

May I recommend possibly going the route with PF86 in stead? Same tube. But.

Difference is lower heater voltage and slightly higher heater current (look this up yourself). Easy to account for in DIY.

The beauty is that the PF86 is incompatible with most hifi, so not only are they cheap and plentiful (still) - but they're also not worth faking. And on top of that, they often seem to behave even better in mics than the EF86..

On average I have had many more PF86's than EF86's of a given batch sounding really good as microphone front-ends. This might be due to the slightly different cathode used for series heating. Or maybe simply because the best EF86's are already gone.

Jakob E.

 

[Arkenberg]

May I recommend possibly going the route with PF86 in stead? Same tube. But.

Difference is lower heater voltage and slightly higher heater current (look this up yourself). Easy to account for in DIY.

The beauty is that the PF86 is incompatible with most hifi, so not only are they cheap and plentiful (still) - but they're also not worth faking. And on top of that, they often seem to behave even better in mics than the EF86..

On average I have had many more PF86's than EF86's of a given batch sounding really good as microphone front-ends. This might be due to the slightly different cathode used for series heating. Or maybe simply because the best EF86's are already gone.

Jakob E.

I see that they are way cheaper but as of right now not many available. So these drop right in? How do you adjust them since the lower heater voltage? What should I be looking for?

Jon

 

[0dbfs]

I used pf86's in Max's original MK7's and they sound great. Very economical too and I have spares!

Cheers!
-jb

 

[Arkenberg]

Ok guys still another question about tubes. I have found many telefunken tubes 86 type but I am in for sure what the difference between, if any, is the ef, pf and ec type tubes. I have searched every where for an explanation but have not seen a description. Is there any one that might know or might know a post about if they are similar.

Thanks
Jon

 

[Rlucas41]

Hello folks,
thought I would contribute to the thread and say how awesome this D-U67 is!!!
I built mine with Tskguy's HK-67, Max Kurcher's BV.12 transformer, and a Tung-Sol EF806 SG tube, in a body from Chunger
.
I have lots of experience with the U67's as the studio I engineer at has 5 of them... The D-U67 I built sounds as lush and creamy with the "air" of the Vintage U67's! I am adding a dropbox link to a ProTools session comparing my D-U67 to a Vintage U67... acoustic guitar and scratch vocal 

Please be kind on the vocal lol!

https://www.dropbox.com/l/sh/0bd6KOEJTznh1H0rcvchfs

 

[Arkenberg]

Ok guys finished my first mic and it sounds great but not sure about one thing. I tryed to adjust my voltages out and I was able to get the -6.3vdc for -h  but I could only get 197vdc for b at the mic with tube installed. Is this an ok voltage or do I need to get it to 210vdc? If so what would you guys recommend for the fix.

Thanks
Jon

 

[Zjcc56]

So I  have finished my D-U67 and its quite the microphone!
something that is bothering me is that it is out of phase with my other mics
i've built it with the AMI T67 trafo and i have checked the wiring from the transformers to make sure that it was all correct by checking continuity between points 1 and 2 from the mic pcb and pins 2 and 3 on the xlr and it seemed fine. (1->3 2->2) also checked pin 3 xlr out to 7 from xformer pcb and pin 2 xlr out to pin 10 from the xformer pcb (3->7, 2->10)
all seems well or am i missing something? is the trafo backwards? or is this just how it is?

sorry if its hard to interpret , it is quite early for me