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

Really wish to see some of those mic coming alive before the end of the world  ;D,

Best,
Dan,

that's in 3 days dany...no time until the next year for my DU-67 build , so i'll just have to ignore the mayan calendar. ;D
edit: yes, still waiting for my capsule to be shipped too, but doesn't change the fact that I would not be able to finish the project by doomsday.

THANK YOU DANY for being a major contributor in making 2012 " The Year of the Mic"!  Can't wait until 2013!  Happy Holidays!

yes, I'll be ignoring the mayan calendar too, until my capsules arrive and Max makes new transformers.

I've got the pcb in the mic, and it looks kind of lonely in there without friends.

Hi,
I need advice on the 220v transformer for the PSU.
I found this in a local shop:
Any chance this will work? There's allways the triad from mouser but if possible id like to avoid the shipping cost.

Features
red leads: 230VAC / 50Hz input
Specifications
voltage: 2 x 12V
current: 1 x 1000mA
rated power: 24VA
weight: 135g
dimensions:
height: 42mm
width: 50mm
depth: 47mm

I got a cheap one off ebay.

http://www.ebay.co.uk/itm/Chassis-Transformer-6VA-20V-20V-/290813757829?pt=UK_BOI_Electrical_Test_Measurement_Equipment_ET&hash=item43b5d9c985

£7.63

works fine in mine.

regards

Spence.

kpearsall said:

yes, I'll be ignoring the mayan calendar too, until my capsules arrive and Max makes new transformers.

I've got the pcb in the mic, and it looks kind of lonely in there without friends.

Click to expand...

thanks Guys,  i will see you in the new world then .. hopefully this will be a renewal for human conscience  ;D
Best,
Dan,

poctop said:

Really wish to see some of those mic coming alive before the end of the world  ;D,

Best,
Dan,

Click to expand...

I'll bring mine with me if I have to. Just need to get a couple more parts together for this road trip. Here's for hoping to find some "real nice" capsules and trafo's on the other side.

Cheers,
jb

I figured out my problems with hum. I had the cable wired with the shield connecting to the jacks, not pin3, which must have created a ground loop. Also, the switch pcb that came with ChuckD's bodies does not ground the switches to the chassis. I added some short wires and it's all good now. 

dmp said:

I figured out my problems with hum. I had the cable wired with the shield connecting to the jacks, not pin3, which must have created a ground loop. Also, the switch pcb that came with ChuckD's bodies does not ground the switches to the chassis. I added some short wires and it's all good now.

Click to expand...

The switch PCB and the switch on the pcb come acrros a gnd plane wich require the 2 hloding pin to be soldered and would make contact with the screw up to the basket portion of the mic , not sure how it can happen but you figured it out  ,  So......... How do you find the mic ,
you have a beezneez ca[psule in there ,  I would appreciate any comments you may have and most off all, congratualtions for your new toy , I really hope you ewill like it ,  any pics ;D,

Best, and Happy End of  the world to evryone , ;D ;D

Let me know ,
Dan,

I don't have my mic body yet but I want to get my tubes burned in. I was thinking about wiring a connector on the the board temporarily and firing it up but I don't want to hook up the capsule without the body. I don't have the any of the switches either (they will arrive with the body).

Do you think it should be alright to fire up as is or should I be temporarily shorting the capsule connections?

Delta Sigma said:

I don't have my mic body yet but I want to get my tubes burned in. I was thinking about wiring a connector on the the board temporarily and firing it up but I don't want to hook up the capsule without the body. I don't have the any of the switches either (they will arrive with the body).

Do you think it should be alright to fire up as is or should I be temporarily shorting the capsule connections?

Click to expand...

I would rather wait till you have a proper enclosure to safley handle ( b+) this new born , just my 0.02.
Best,
Dan,

I'm not too worried about the B+ since it's fairly low voltage. I planned on using my circuit board Pana Vise with a little Plysil 69kV tape to make things safe.

I wouldn't be worried about burning tubes in.
I'm with poctop, build it right and safely.
You can sub the capsule with a 50-100pf capacitor if you don't have it yet.

Well change of plans anyways. Holiday season is brining some unexpected guests so I have been reassigned to cleaning detail. My microphone body should be here before I get back to to working on the mic. Plus the IIHF World Junior tournament is starting. All of a sudden watching TV is more important than building mics!

Yep got the same Cleaning Duty Here,  ;D

So I swept the frequency response of mine using the calibration port and RMAA. The gain staging was setup as described in the manual; this result is normalized.
I wonder if the spec to be -10 dB at 1500 cps should actually be -10 dB at 15 000 cps?

Where do you see a spec of 10db down @ 1.5kHz? That wouldn't be very functional. It looks to me like some of the specs have a 3dB down point of 16kHz but you are 10dB down at that point.

Although that could be your interface or RMAA exaggerating the curves with high frequency attenuation.

I don't see the "gain staging" setup in the manual though. Maybe I'm not on the same wavelength as you. I did find some interesting information of mic stands including a boom attachment!

From the manual: (The page was posted back in this thread)

"For purposes of checking the frequency response of the amplifier, a test signal may be fed to the instrument jack marked "calibrating input" at one end of the power supply. Proceed as follows: From the 600 ohm output of a signal generator, feed a 1000 cps tone at a level of -18 dbm to the calibrating input. You may use the model z-58 dummy head or can proceed with the regular head assembly plugged in. The three switches are set for "omni", full sensitivity, and linear frequency response. The following output levels are to be observed at the output of the 150/250 ohm impedance, using a vacuum tube voltmeter:

1000 cps:    -38dB    1dB
40 cps:        -43dB    1dB
1500 cps:  -48dB      1dB

Click to expand...

I didn't use a 600 ohm output, just the regular output from my soundcard. The soundcard is flat - the green line is out and in for reference.

Hi fellow DIYers

I want to finally approach building a great quality mic, actually a couple to use for my drum rooms and to have an alternative to the Sony c800g for vocals that i have in the studio.

So far I have built successfully a few LA2A - LA3A - LA4 - 1176 - SSL G Buss, racapped and modified my MCI board but I would not call myself a tech quite yet...

Which projects do you guys suggest ? 87s ? 67s ?

Which one has the most comprehensive info and parts availability and would be a good one to start with considering for microphone I have only built the Royer Ribbons replicas that are very easy...

Eventually I wanna build the 47 and 87 and the 67 but I am sort of intimidated by the pictures of the 67... though i have recorded with those and I love the sound...

I would appreciate opinions...

sage

Hi Sage,

I am very interested in doing a good valve compressor build (Tube Tech C1 would be nice!), i have a Art Pro Vla which i am gonna mod but thats gonna be down the line a bit.
I would suggest a U67 build and U87, build a pair of them.
I have had awsum results with the U67 on acoustic/electric guitar and vocals, doesnt sound that great in with a drum kit, better mics out there which seem to sound much better.
U47 FET is the one you'll want for kick drum and bass guitar( I have a pair but not built bodies yet for them).
I use the U87s over the kit and they sound fantastic( plenty of donor bodies available for these).
Havnt tried the U87's on the toms yet but some people say this is good.
good luck with it all.

regards

Spence.