MK-U47 - build thread

ok, the mic build is completed for now, moving on to the psu:

I am using the collective cases psu with Binder connector, the recommended part number is # 09 0044 00 07 which is available from Conrad as catalog number 739030 (€20,99)

As this is a 7 pin connector it got me thinking if I would be possible to find an equivalent 6-pin Binder connector, like the supplied connector from Max, but it seems they are only available as 5 or 7 pin versions. Too bad, because the 6 pin versions are a lot cheaper...

anyways, the 7 pin cable plug is also available from Conrad as catalog number 739006 (€28,99). Not meaning to promote this company  but maybe this info helps other builders...

Excuse my lack of knowledge, gdiy crowd - i understand about the buildup of lowend in cardioid, but why does my beloved MK-U47 even have more lowend if i slightly tap the mic body while in cardioid compared to omni?

frans said:

Excuse my lack of knowledge, gdiy crowd - i understand about the buildup of lowend in cardioid, but why does my beloved MK-U47 even have more lowend if i slightly tap the mic body while in cardioid compared to omni?

Click to expand...

Because the body is in close proximity of the capsule?

Wouldn't it then not be the same "ooooomph!" if i tap while in cardioid AND omni? But in omni it sounds leaner.

frans said:

Wouldn't it then not be the same "ooooomph!" if i tap while in cardioid AND omni? But in omni it sounds leaner.

Click to expand...

The bass build up in cardioid is caused by the proximity effect.  It doesn't matter if the sound source is a voice, a guitar or a microphone body used as a drum. As long as that source is close to the capsule (the mic's body very much is, obviously), there'll be a noticeable bass build up in cardioid.

Then there's the direct coupling (not the case with other sound sources). "Handling noise" is not the same thing as proximity effect, but I'd say they're connected. Omni's, especially true pressure mics, are known to have low handling noise.
On the other hand, true omni condensers go deeper into the subsonic range.

And then there are dynamic moving coil mics that have their own physical idiosyncrasies.

Comparing my MK-U47 to an original U-47 and my Chunger/Matador C12 to an AKG C12 VR at Pama Records Studio 3 in Sweden.
The MK-U47 and the U47 sounded so similar that Pama want me to build a MK-U47 for them.
The Chunger/Matador C12 sounded so much better than the (familiar) AKG C12 VR that the studio owner was a bit stunned. Lots more openness and details in the middle range.
I’m not sure that he has ever heard a “real” C-12. To my ears, the AKG C12 VR sounded flat and a bit dull.
Sorry, no clips at this time.

In the C12 what capsule and transformer?
In the 47 what tubes, transformer and capsule?

Chunger/Matador C12: CT12 capsule, AMI transformer (from Chungers C-12 kit) and Mullard 12AT7 tube.

MK-U47: Thiersch Red Line capsule,  Max's Bv.08 transformer and two WE 408A tubes.

stelin said:

The Chunger/Matador C12 sounded so much better than the (familiar) AKG C12 VR that the studio owner was a bit stunned. Lots more openness and details in the middle range.

Click to expand...

Never underestimate the improved sonics one gets with a yellow PCB.

Hi Everyone,

just wanted to let you know that I'm working on the next batch, which should become available in approx 3 to 4 weeks.

-Max

I finally have had the pleasure of using my mike, long story short I damaged my cap and had to send it back blah blah blah.

But i was recording with my mike yesterday with We 408a's, although they are still burning in and the cap is brand spanking new, I am so pleased with the presence and tone of the mike;its voice ! Everything I had hoped for and more. Great work Max !

Thx Max, Cat5 and TonyC: you all know why

my 47 starting off right burning in listening to the beatles on repeat !

Thanks Matt!

For those who haven't followed the RGO boards, lots of activity over here for the MK-U47, including a tube choice worth looking into:

http://realgearonline.com/thread/2473/jks-mku47-build-thread

http://realgearonline.com/thread/2859/winecamp-mic-pre-shootout

Thanks for the link - been away from the net for a couple of days !

-Max

Max,

The MK-U47 uses two tubes. I want to check the noise level of individual tubes. I have a bunch of 408a tubes and I want to find the least noisy ones.
Is there any practical way to test a single tube for noise in the MK-U47 circuitry?  I understand that the heaters are connected in series, so I would have to replace the second tube with a resistor to compensate for the missing heater, but beyond that I don't know what I can and can not do.
Any advice or thoughts about that?

- Stefan

Yes that's possible - just connect a 400 Ohm resistor (2watt or larger) to the heater pins of the second, unused tube socket.
-Max

My MK-U47 is complete. Did a comparison between the MK-U47 (which has a Thiersch Red Line), a Neumann U47 with a K47, and also my C12 clone (Tim Campbell capsule) and a Neumann M269 thrown in the mix for fun.

Here's a sample of each microphone:
Mic 1: https://www.dropbox.com/s/ca6uywhw7f355g6/Mic%201.wav?dl=0
Mic 2: https://www.dropbox.com/s/adytkn2rw3lvdm8/Mic%202.wav?dl=0
Mic 3: https://www.dropbox.com/s/hnp82zqm8db11tr/Mic%203.wav?dl=0
Mic 4: https://www.dropbox.com/s/6nja0uu3uugep1l/Mic%204.wav?dl=0

See if you can guess which is which  .

Inglev said:

My MK-U47 is complete. Did a comparison between the MK-U47 (which has a Thiersch Red Line), a Neumann U47 with a K47, and also my C12 clone (Tim Campbell capsule) and a Neumann M269 thrown in the mix for fun.
----
See if you can guess which is which  .

Click to expand...

#1 = MK-U47
#2 = C12
#3 = Neumann U47
#4 = M269

Inglev said:

My MK-U47 is complete. Did a comparison between the MK-U47 (which has a Thiersch Red Line), a Neumann U47 with a K47, and also my C12 clone (Tim Campbell capsule) and a Neumann M269 thrown in the mix for fun.
See if you can guess which is which  .

Click to expand...

...no vocals?...

kidvybes said:

Inglev said:

My MK-U47 is complete. Did a comparison between the MK-U47 (which has a Thiersch Red Line), a Neumann U47 with a K47, and also my C12 clone (Tim Campbell capsule) and a Neumann M269 thrown in the mix for fun.
See if you can guess which is which  .

Click to expand...

...no vocals?...

Click to expand...

Only had time for a quick guitar test when I had the setup.... plus, I'm not the best singer  .