wa 47

[gyraf]

We had a pair of real (vf14) u47's equipped with brass ck12's - these still had those very sweet low-mids we usually only got from u47's

(I'm on the edge wether the m7 or the ck12 actually sounds best in there..)

/Jakob E.

 

[Purplenoise]

you guys sure it's the capsules? i put a third party capsule in a real u47 for fun and that 3d quality appeared...

I believe it’s mostly the capsule but of course there are other factors too. The slightly microphonic nature of vf14, transformer, headbasket/body resonance etc. A mic is a synergy of parts and sometimes you get…a perfect storm.

 

[kingkorg]

headbasket/body resonance etc.

I sometimes joke, u47 is just a capsule attached to a helmholz resonator. These effects are very real and prominent.

 

[Whoops]

A mic is a synergy of parts and sometimes you get…a perfect storm.

Or it's just a Storm but after many years of people getting used to it then it becomes a reference

 

[Purplenoise]

Or it's just a Storm but after many years of people getting used to it then it becomes a reference

Haha…maybe. But then again sound is so subjective. I happen to love the 47 sound…first time I heard one, before I even knew what it was, I was starring at the speakers like an idiot. I never ever had this reaction with any other mic. There is something about this “family” of sound that ticks something in me..

 

[xeawr]

We had a pair of real (vf14) u47's equipped with brass ck12's - these still had those very sweet low-mids we usually only got from u47's

(I'm on the edge wether the m7 or the ck12 actually sounds best in there..)

/Jakob E.

This affirms what I've been thinking for years: In my opinion the VF14 tube in the U47 matters much more than many (engineer/mic-cloning-companies) think or want us to believe.

How come we have such a variety of K47-capsules and mic bodies but practically nobody nails the 47 sound?

On a different note: There are some crazy "modders" out there, why would you put a brass CK12 in a U47? (Reminds me of my two UM70S, that came with teflon CK12 capsules before I had them replaced with PVC M7s...)

 

[xeawr]

Haha…maybe. But then again sound is so subjective. I happen to love the 47 sound…first time I heard one, before I even knew what it was, I was starring at the speakers like an idiot. I never ever had this reaction with any other mic. There is something about this “family” of sound that ticks something in me..

exactly the same experience here. I remember hearing a recorded vocal track (U47) - I didn't know which mic was used. I sat back in my chair and was like in total awe for half a minute. I can't help it, I just really really like the sound...

 

[kingkorg]

This affirms what I've been thinking for years: In my opinion the VF14 tube in the U47 matters much more than many (engineer/mic-cloning-companies) think or want us to believe.

How come we have such a variety of K47-capsules and mic bodies but practically nobody nails the 47 sound?

On a different note: There are some crazy "modders" out there, why would you put a brass CK12 in a U47? (Reminds me of my two UM70S, that came with teflon CK12 capsules before I had them replaced with PVC M7s...)

No body nails it because u47 is all over the place. Not a rocket science to clone a particular u47, but then you compare it to another one and it sounds way different. The same goes for a lot of other mics. The other issue might be cloning a microphone with failure of some sorts, and replicating that quirk. The originals have been beaten to death and most are out of spec, so should one try to clone a broken mic?

 

[doqmemory]

why would you put a brass CK12 in a U47?

It is a nice, flat circuit, so it seems a (good sounding) CK12 should work great.

I have a bunch of old B2 and B2 Pro mics with interchangable heads that I am planning on making into "mix and match" microphones, with different circuits and different capsules. I have several AMI T8 transformers (small, T-14 sized, but with Bv.08 ratio) to use for U47-style circuits (EF80/8000/802 tubes) in those bodies. We'll see how different capsules sound in the same U47 circuit then. I have one each Thiersch M7 red line, 3U Audio M7, MHBO CK12, BeezNeez M7, K7, and CK12 reserved for them.

For the preamps, I plan to use U47-style (Oliver Archut's alternate version), U49-style (again, Oliver's version), ELA M251 (based on @Matador's version), KM84 (from Jonathan Burtner's FET847 design), @homero.leal's pimped Alice, and maybe a C12-style, too.

I have most of the parts, I just need the time....

 

[tomas.borgstrom]

you guys sure it's the capsules? i put a third party capsule in a real u47 for fun and that 3d quality appeared...

I agree, of course all the components and the proper dimensions and quality of them are important but a an original U47 with an inferior capsule (clone or a Neumann K47 with too much high mid) does not sound pleasing. To my ears a great sounding M7 is the most important part. I would love to hear/have one with a vintage CK12.

When using another tube than VF14 the circuit must be adjusted so that it can properly drive the BV08. In most clone schematics I've seen the plate resistor is unchanged from 100K. When using EF12 with 10K plate resistor as in CMV5 the low end is much better and to my ears the sound is extremely close to VF14.

U47 is great on vocals, but there are often other microphones that match a certain voice better. My biggest experience recording vocals is Elam 251, so relaxed in the highs were the Neumanns and a lot of other microphones can be problematic. I wouldn't be surprised if I would enjoy the U47 better with a vintage brass CK12 and perhaps began using it more often on other sources.

 

[tomas.borgstrom]

No body nails it because u47 is all over the place. Not a rocket science to clone a particular u47, but then you compare it to another one and it sounds way different. The same goes for a lot of other mics. The other issue might be cloning a microphone with failure of some sorts, and replicating that quirk. The originals have been beaten to death and most are out of spec, so should one try to clone a broken mic?

I'm convinced the U47s of the same revisions had pretty much the same sound when they left the factory.

 

[tomas.borgstrom]

The biggest problem today is that there's no way to verify the sound of a M7. The original Neumann Berlin is out of spec since many years. I've seen a 15 year old Gefell M7 that was completely cracked. The microphone was otherwise in perfect shape.

 

[kingkorg]

I'm convinced the U47s of the same revisions had pretty much the same sound when they left the factory.

Early ones with glued M7 and 100% manual machining, pvc production and side matching by measuring capacitance?

 

[tomas.borgstrom]

Early ones with glued M7 and 100% manual machining, pvc production and side matching by measuring capacitance?

Haha, perhaps not them, who knows? I came across an M7 from 1932 serial 29. It had less bass and still had after reskinning so it must have been the backplates. To my eyes it looked the same. Either it was a bad sample or they had improved 20 years later when the U47 was released.

I still have a picture that Neumann had an extremely high quality control. I haven't measured the glued M7 from Theirsch but I've heard several and I find them to sound the same. I can accept it in some way if we're talking about the capsule but not the electronics. It's constantly stated that old high quality equipment sound all over the place. That's true 60-70 years later without proper service, but I'm convinced that wasn't the case back then.

What I know for shure is that today the major problem with the U47 I service is the capsule. Some have bad tubes but the main reason they sound different and bad is old cracked M7, dirty and worn K47, reskinned M7 and K47 with a thinner sound and new K47 with a harder sound. If the tube and the capsule are ok you can clean it, restore the electronics if needed and get a microphone with a pretty predictable sound.

 

[xeawr]

I'm convinced the U47s of the same revisions had pretty much the same sound when they left the factory.

Me too. Regardless of how "hand-made" everything was, back in the days. They had good ears to judge each mic, and the company could (no 'had to') financially afford it. If it wasn't so, only few people would know and nobody would care what mics were used 50, 60 or 70 years ago

 

[xeawr]

It is a nice, flat circuit, so it seems a (good sounding) CK12 should work great.

I have a bunch of old B2 and B2 Pro mics with interchangable heads that I am planning on making into "mix and match" microphones, with different circuits and different capsules. I have several AMI T8 transformers (small, T-14 sized, but with Bv.08 ratio) to use for U47-style circuits (EF80/8000/802 tubes) in those bodies. We'll see how different capsules sound in the same U47 circuit then. I have one each Thiersch M7 red line, 3U Audio M7, MHBO CK12, BeezNeez M7, K7, and CK12 reserved for them.

For the preamps, I plan to use U47-style (Oliver Archut's alternate version), U49-style (again, Oliver's version), ELA M251 (based on @Matador's version), KM84 (from Jonathan Burtner's FET847 design), @homero.leal's pimped Alice, and maybe a C12-style, too.

I have most of the parts, I just need the time....

This sounds interesting. Please report your finding (and keep some recordings)

 

[tomas.borgstrom]

Me too. Regardless of how "hand-made" everything was, back in the days. They had good ears to judge each mic, and the company could (no 'had to') financially afford it. If it wasn't so, only few people would know and nobody would care what mics were used 50, 60 or 70 years ago

The big national TV and radio broadcasters in Europe together with the major record labels were very important customers back then. They had a lot of influence and they all had their own very skillful engineers. If they received anything picking up RFI, being noisy or out of spec they would send it back immediately. I've heard several stories about Neumann and other companies having to revise a product in very specific ways to satisfy the National radio broadcasters.

 

[kingkorg]

Guys, with all due respect i don't think you realize what goes into this kind of manufacturing, and what kind of tolerances we are talking about. I don't think you realize how frequency response and other measurements were conducted back in the day. Just look at component variances from the period. Of course those could be selected carefully.

M7 design was pretty much something they had just figured out, and no matter how big emotional response these mics bring today, by modern standards technoques used back then are stone age. The very proof of this is the fact Neumann moved on to k47 and gave up on pvc. You are aware how PVC film was manufactured back then?

Backplates are also all over the place. So many poeple who recreate these have measured the dimensions, and variations are present from hole to hole, not to mention capsule to capsule. Today drill bit wear is compensated by the machine, there was no such thing back then, and it's obvious.

The magical vf14 was used due to convenient operating voltage, not because it was special. It was readily available tube used in radios.

U47 is a masterpiece, historical piece of art. But i prefer keeping things real. What i'm talking about is reported my many knowledgeable people during the years.

Mentioning those large broadcasters, you are aware of the fidelity and quality of the signal that was broadcasted, and how it was reproduced at home? Large hi fi 30-20000hz devices? Audio band pretty much ended at 10.000hz, take a look at Neumann's pattents and see what they regard as audible range.

 

[Purplenoise]

Guys, with all due respect i don't think you realize what goes into this kind of manufacturing, and what kind of tolerances we are talking about. I don't think you realize how frequency response and other measurements were conducted back in the day. Just look at component variances from the period. Of course those could be selected carefully.

M7 design was pretty much something they had just figured out, and no matter how big emotional response these mics bring today, by modern standards technoques used back then are stone age. The very proof of this is the fact Neumann moved on to k47 and gave up on pvc. You are aware how PVC film was manufactured back then?

Backplates are also all over the place. So many poeple who recreate these have measured the dimensions, and variations are present from hole to hole, not to mention capsule to capsule. Today drill bit wear is compensated by the machine, there was no such thing back then, and it's obvious.

The magical vf14 was used due to convenient operating voltage, not because it was special. It was readily available tube used in radios.

U47 is a masterpiece, historical piece of art. But i prefer keeping things real. What i'm talking about is reported my many knowledgeable people during the years.

Mentioning those large broadcasters, you are aware of the fidelity and quality of the signal that was broadcasted, and how it was reproduced at home? Large hi fi 30-20000hz devices? Audio band pretty much ended at 10.000hz, take a look at Neumann's pattents and see what they regard as audible range.

Yes true. Even today Neumann capsules aren’t 100% matched..some far from it. Tubes?…rarely 100% either. Still thought, besides the variations, u47s sound like u47s…even the straight conversion with the nuvistor without changing bias. For me the “47” sound is not the fuzzy, warm, whatever low end. It’s about that smooth 3D forward midrange and that’s the area most clones fail to caption accurately. Technically you are right though, I have heard at least five originals and the all sounded a little different

 

[kingkorg]

Agree 100% on that part.