MK-U47 - build thread

Interesting first post.

Anyway, welcome!

As for contents. I'd agree that the digital medium is different than the old tape setup and that microphones could/should be chosen accordingly. I think this is one of the reasons ribbon microphones have been making a come back, as have tubes and trannies.
But trying to make a clone is trying to make a clone. Not to mention the fact that this one does have a tube and tranny. And back in the seventies when tape was at its prime, no one wanted a (tube) U47.

Another way of looking at it would be getting as close as possible to the sound, but with modern parts. This is considered impossible by many, but some do seriously try. Here's an example. No affiliation and no opinion from me, yet:
http://www.youtube.com/watch?v=9m0B1pKZRT4&feature=youtu.be

I wouldn't overstretch the tape vs. digital discussion. A U47 sounds fine on both mediums.

Personally, I don't get the recent obsession with transformer laminations. When we talk about a U47 clone we must consider that the mysterious VF14 tube is unobtanium. As anyone knows, a transformer is only as good as it fits the circuit. So, without the original tube, the original transformer may be optimal anyway. What I really would prefer - this is of course my personal view - is a non-original transformer optimized for a non-original tube that in conjunction come as close as possible to the original combo.

Also, it's been said many times, but I guess it needs repetition: Most of the sound is in the capsule. Anyone not willing to pay top dollars for a genuine Neumann K47 or (working!) Berlin M7 capsule should not worry too much about historically correct laminations. Any capsule substitute is likely to make much more of a difference than the transformer lams. Especially, if we're talking about slight differences as in the above "lamination wars".

I don't agree with your premise. Neumann designed the U47 to sound great using currently available tecnology and materials. I have a bunch of vintage microphones at the studio and never have I chosen a microphone based on whether I was printing to tape or digital.

No one has thrown out their U47's because they don't sound great recorded to digital.

Regards,
Mark

liquidify said:

For example, early mics such as the 47 were designed to sound good on tape machines.  For the most part, tape machines are not used today.  There are a substantial number of differences between a recording done on a tape machine vs. one that is not. 

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micaddict said:

Interesting first post.

Anyway, welcome!

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Thanks for the welcome.  I am a long time lurker.  Figure it was time to talk since I am interested in building this kit.

Any word on developments and release times?

Wow way off topic but.

All that is true and more. The signal chain has changed greatly since the inclusion of these mics into the pantheon of mic lore. No one mic does everything people. The design philosophy behind the inclusion of the VF14 tube was being able to run it on a single supply voltage period (oops I made a verbal punctuation). How else would you explain that when the VF14 tube was no longer available they settled on the Nuvistor?! Wouldn't it have been a lot better, and more responsible to re-tool the mics already in the field and redesign the new ones to accept the EF80 or EF800? The latter being, a lot of people who know a lot more than I do about mic circuitry's, choice for a modern build. The former being a successor tube in the VF, UF and EF14 evolutionary history. Andreas Grosser (a legend in the Neumann community) claims to have a FET solution that plugs directly into a stock VF14 tubed U47 and he dares you to tell the difference. Never ever underestimate a manufacturers (even Neumann) need to meet a market price target!

I agree with Rossi that the capsule is the input and it all begins there just like the lens on a camera.

I have actually heard of people getting rid of there fantastic tube mics for new inclusions into the pantheon for the same reasons that trusted tried and true mics of yore were cast aside due to the "new better ones" coming along. Also in a commercial environment reliability is a must. I have rented vintage gear from reputable sources and had it fail at the worst time. Just because its old.

I myself have fallen back in love with my ribbons and dynamics because of the low noise and expanded dynamic range of digital recording and advancements in preamp architecture.

Transistors vs Tubes, Condenser Mics vs Ribbons and get ready Digital vs Analog. Oye does it sound good do you like what you hear if yes than we all win! 

Another My Two Cents Moment.

Yes Welcome

Yes I want my IOAudio Body Max. But good things come to those who wait. Right?

Pip, all new U47s had a VF14 tube. The nuvistor was merely a retrofit so users could use a commonly available tube. At the time many studios replaced tubes routinely *before* they would fail in order to avoid troubleshooting during a session.

Of course one of the main motivations behind the VF14 was the single voltage power supply. But that technique led to a quite unique circuit, and since that circuit is so simple, every one of its very few components plays some part in its sound. Apart from that, the VF14 is lower noise than most tubes. Also, there is the underheating aspect - few tubes can stand severe underheating for so long.

Andreas Grosser's FET retrofit seems like cool solution. To my knowledge, he doesn't sell it separately, though.

Rossi said:

Pip, all new U47s had a VF14 tube. The nuvistor was merely a retrofit so users could use a commonly available tube. At the time many studios replaced tubes routinely *before* they would fail in order to avoid troubleshooting during a session.

Of course one of the main motivations behind the VF14 was the single voltage power supply. But that technique led to a quite unique circuit, and since that circuit is so simple, every one of its very few components plays some part in its sound. Apart from that, the VF14 is lower noise than most tubes. Also, there is the underheating aspect - few tubes can stand severe underheating for so long.

Andreas Grosser's FET retrofit seems like cool solution. To my knowledge, he doesn't sell it separately, though.

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Yes sorry did not mean to imply that a U47 was manufactured new with Nuvistor. Yes the points you make are true about the tubes underheating longevity, it did have a 60v filament! Quiescent electrically yes, but not when comes to microphonics, actually rather lackluster in this respect thus all the internal shockmounting and padding.

Look lets face it good things stand the test of time! No?

I believe Mr. Grosser does sell his VF14ef seperately. But my German stinks so check it out.

http://www.voxorama.com/service/detail/andreas-grosser-vf14ef.html

Pip said:

I believe Mr. Grosser does sell his VF14ef seperately. But my German stinks so check it out.

http://www.voxorama.com/service/detail/andreas-grosser-vf14ef.html

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The text states that the VF14ef is not sold separately but can only be ordered as an option when you have your mic repaired or checked by Andreas Grosser.

Rossi is correct. I have spoken with Andreas many times; in fact he's done work on a microphone of mine. I wanted to build a U47 clone and buy the FET version of the VF14 from him, but he said this is something only he installs personally.

Apparently he used to sell them separately, but he no longer offers this as an option.

HTH,

Mike

Would he install it into your clone?  I'd try that if so.

Rossi said:

Pip said:

I believe Mr. Grosser does sell his VF14ef seperately. But my German stinks so check it out.

http://www.voxorama.com/service/detail/andreas-grosser-vf14ef.html

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The text states that the VF14ef is not sold separately but can only be ordered as an option when you have your mic repaired or checked by Andreas Grosser.

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Thank You for the translation and forwarding of information. It's a shame as it would be interesting to experiment with this. If anyone contacts him ask about his installing it into a clone. My feeling is that he has his reasons for wanting to implement the install but that doesnt mean he won't sell it for other mics. Maybe?

Pip said:

Rossi said:

Pip said:

I believe Mr. Grosser does sell his VF14ef seperately. But my German stinks so check it out.

http://www.voxorama.com/service/detail/andreas-grosser-vf14ef.html

Click to expand...

The text states that the VF14ef is not sold separately but can only be ordered as an option when you have your mic repaired or checked by Andreas Grosser.

Click to expand...

Thank You for the translation and forwarding of information. It's a shame as it would be interesting to experiment with this. If anyone contacts him ask about his installing it into a clone. My feeling is that he has his reasons for wanting to implement the install but that doesnt mean he won't sell it for other mics. Maybe?

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I asked Andreas about this.  I am currently buying one of his Voxorama u47's so I have been in frequent contact with him.  He said that if he sees the microphone and all is up to his standards, he would put his vf14ef in it.  He was particularly concerned with the quality of the power supply.  I did not ask him if this offer was something that he would extend to everyone, but I assume it would be.  Andreas seems to be a very nice guy and a person who cares about quality microphones.  He is extremely busy though, and duties to and from Germany are not something to be taken lightly.  I would suggest contacting him personally.

just a quick pic of the finished end bells.

Any updates about the release schedule?

Not as fast as i would like to - but i'm constantly adding new stuff.
Here's the transformer-resistor-cap Pcb assembly:

Not as fast as i would like to

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The problem now of course is
To simply hold your horses
To rush would be a crime
'Cause nice and easy does it every time

The trafo assembly put in the mic:

Looks splendid! I'll try to hold my horses, but it's really difficult.

It really is looking quite nice. I have one thought. Would it be possible to leave some more room between the bottom of the Transformer deck and the base of the mic? I would really like to use a PIO can cap here so a bit more room would be nice. Just a thought.

EDIT: I thought a little more. Maybe two mounting choices on the rails one a bit more towards the top of mic.