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

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

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Sure, I'll try to put something up.

The Store is back online,

Happy New year All, 
Best,
Dan,

There is a public file on soundcloud that has the DU-67 on drum overheads in a M/S arrangement. I don't know if this is helpful, voice is the king for assessment but there ain't a lot of that going on around here. The search is Pete Hillman and the track is titled "undisciplined".
Happy New Year,
Pete

Here's some quick samples. I had both mics set up at the same time next to each other, and was singing about a foot or so back.
This was just a quick test - not meant to be great in anyway. (But for the great song by the late great W.rr.n Z.v.n!)

U67: Beezneez - Telefunken EF86 - ioaudio bv12
u67 -> DIY Jensen990 (i.e. JH M1) - > echo layla24
http://soundcloud.com/dmpro/u67-sample-16bit

C12: T.Campbell C12 - GE 6072 - CM2480
c12 -> DIY Jensen 990 -> echo layla24
http://soundcloud.com/dmpro/c12-sample

Recorded 44/24, normalized, then exported to 16bit for the upload

Thanks!

Same polar pattern on both?

U67> relatively mellow and full. More direct, too.

C12> bright, open, more ambient. But also somewhat harder on the voice.

Here I prefer the U67.

Both were set to Cardiod.

micaddict said:

Thanks!

Same polar pattern on both?

U67> relatively mellow and full. More direct, too.

C12> bright, open, more ambient. But also somewhat harder on the voice.

Here I prefer the U67.

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Nice sample DMP , listen to both sample and i agree 110% with miccadict.  Thanks for taking the time in doing this , i just love my D-U67  8)
Dan, 

Hello builders,

I finally started populated the main pcb and I got to C17. The pcb and the files in the build folder say it's polarized...is it? If so, how do I determine the polarity? There's no "+" anywhere on the cap, just "100J 630V" (purchased from justradios.com). Any help is much appreciated, thanks.

-DUDE GUY

Same question as above for C10, the second styroflex. Thanks.

-DUDE GUY

Those caps do not have a + / - 
They can go in either way

I fired mine up last night!  Sounds great.  I have a small issue I need to sort out but overall very impressed.  I need to spend more time with the mic but I am excited about this build for sure.  Thanks Dan!

EDIT:  I got my small issue fixed and the mic sounds great!

Thanks very much, dmp. I guess the pcb denotes polarity incase someone chooses not to use a styroflex? Anyway, I finished populating the main and socket pcb, building the psu tomorrow. I will post pics.

-DUDE GUY

dandeurloo said:

I fired mine up last night!  Sounds great.  I have a small issue I need to sort out but overall very impressed.  I need to spend more time with the mic but I am excited about this build for sure.  Thanks Dan!

EDIT:  I got my small issue fixed and the mic sounds great!

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Thanks Dan,
Dan, 

I noticed that the PSU BOM lists a quantity of 3 Zener diodes, 15V 5W. What's the reason for this? Do I need to select one with a certain characteristic? Thanks.

-Kevin

Hi Guys,

just tested 3 different tubes in my U67 build.
results as follows:

EF86 Winged C - full open, good clear top end, full bottom end
EF86 Sovtek Electro Harmix - little bit darker than the winged C, cheaper sounding
EF86 - Tung Sol - muffled, didnt like this one at all, IMHO dont buy this one.

have some sound files which i'll put up later, done on fig 8, mesa boogie dual rectifier, channel 2, into GS3000 Allen & Heath then into Protools HD via 96i, little bit of compression from Art Pro VLA, nothing else.

regards

Spence.

Got a working mic! Been super busy, so only cursory testing, but sounds amazing. Will try to test it against my partners vintage 67 next week if time permits.
I am noticing a bit of hum when i touch the body, especially when engaging the pad switch. I have not yet tried jumping 2 and 3 in the power supply, so i will give that a go.
I also couldn't hear a difference in the low-cut switch, so may need to revisit that as well..
My Tele EF86 tube is a bit noisy. I'll give it some time to see if it quiets down. I love this mic, probably my fave mic design ever.

One tip that i didn't see in the thread, and this is in regards to the "Chunger bodies": You need to mount the switch/spacer assembly from the bottom. I initially did it from the top. The pattern switch is right in the way of the screw for the headbasket. You need to tighten the headbasket and then tighten the assembly afterwards. It takes some maneuvering to get the screws to sit right, but can be done
Thanks for putting it all together!
Ian

imo said:

Got a working mic! Been super busy, so only cursory testing, but sounds amazing. Will try to test it against my partners vintage 67 next week if time permits.
I am noticing a bit of hum when i touch the body, especially when engaging the pad switch. I have not yet tried jumping 2 and 3 in the power supply, so i will give that a go.
I also couldn't hear a difference in the low-cut switch, so may need to revisit that as well..
My Tele EF86 tube is a bit noisy. I'll give it some time to see if it quiets down. I love this mic, probably my fave mic design ever.

One tip that i didn't see in the thread, and this is in regards to the "Chunger bodies": You need to mount the switch/spacer assembly from the bottom. I initially did it from the top. The pattern switch is right in the way of the screw for the headbasket. You need to tighten the headbasket and then tighten the assembly afterwards. It takes some maneuvering to get the screws to sit right, but can be done
Thanks for putting it all together!

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Thanks For the nice word,

1)  I have not yet tried jumping 2 and 3 in the power supply, so i will give that a go.
have you installed the SHLF jumper in the psu this will starground the mic cable shield and body.

A)  I am noticing a bit of hum when i touch the body, especially when engaging the pad switch.

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Make sure the 2 leg of the switch are soldred because only one of the pins goes to the ground plane of the switch pcb you need to use metal screw to fit them there so you would have a perfect short betwen the switch and the body  you need to use the 3 screws to make sure the grounding is good tight them up ,
had the same problem as soon as i was touching a switch and tight it up and then gone

B) I also couldn't hear a difference in the low-cut switch, so may need to revisit that as well..

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make sure you have the 2 wire solder on top of the jumper LC on the main board mic .

C)  You need to tighten the headbasket and then tighten the assembly afterwards. It takes some maneuvering to get the screws to sit right, but can be done
Yes the mic design by itslef implies that you cannot install the headbasket after the switch board but if you remove the screw and loose them just a notch you can acces the headbasket screw.

D)My Tele EF86 tube is a bit noisy I'll give it some time to see if it quiets down. I love this mic, probably my fave mic design ever.

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Many thanks for that and thanks for posting , 

Keep us posted 

Wiring Questions I can't see in build guide.
7 pin connector numbers connect to same numbered holes on main P.S.B.
Where do the switch board wires connect?
Where do the wires from the capsule connect?

Wiring Questions I can't see in build guide.

7 pin connector numbers connect to same numbered holes on main P.S.B

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yes Makes it easier.

Where do the switch board wires connect?

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Did you download and look all the file in the build folder. there is a file called overall connection you need to understand this file 100%
before starting wiring. Attached in this post

https://cdn.groupbuilder.com/groupdiy/u/39511/58d0281993a88

Where do the wires from the capsule connect?

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see file.

Hope this helps,
dan,

Capsule:
Front diaphragm center lead goes to right side turret (if holding the mic straight up and the tube facing you)
Rear diaphragm center lead goes to pattern switch pin 2 (actually soldered to the switch)
backplate lead goes to left turret (mic orientation same as above)

Dave

It is important to try to use Dany's overall connection diagram as well!