Measured VF14 characteristic

[o3misha]

Strange... I did not find any word  about modern FET design in NU47. Did Martin said that NU47 contains fully new part, including FET solution? Fet microphone for more than 4000 $?????

 

[marcus4audio]

Im sure that someone here can kindly ask Martin is his design based on tube or fet. As I can see he is very active on forums. Unfortunatelly I don't know him.

 

[tubestation]

Hello,
I just was reading the nu 47 pdf . Outputconnector via 3 pin XLR from the Powersupply.! I think that says all ? I think he is using a high Voltage in a Phantom Power
configuration to power some high Voltage Videotransistors?
Greetings
Lothar

 

[o3misha]

I see only 7-pin Binder connector on NU47v microphone in PDF and in youtube video. NU47V - tube microphone! 3-pin XLR - its usual output audio connector from PSU.

 

[tubestation]

Have a look here. http://www.nu47.com/NU-47V.pdf
Sorry i just realised that he means the Outputconnector.

 

[tubestation]

Hello,
Thank s for the Links.
When we did a Comparisment with a Vf 14 equipted 47 and the Andreas Replacement , we noticed the same as you can hear in the Videos. At low Levels like Speach or Atmo they really sound very equal ,but if it get s louder the Replacement sounded different ,in the Body and in  the Highs. When screaming into the Mic or in Front of loud Drums the dynamic distortion was more different,was getting a little hard and sharp and smaller in the Picture. It wasn t bad at all ,just different but very useable and more or less in the Ballpark what you would expect from a Vf14 . For me the fet Replacement didn t sound like a 87 at all.
I am very happy and thankfull for all the Energy You all invented into this Analysis and the Research already done and posted here, and wish You all the best for a good Result for your Fet Replacement,Frederic !!.( i accedently hit the Like Button where i didn t want to, i am using a Pad to scroll the Page)
I think the absence of a Vf14 Remake shows the bad Situation of the Recording "Industry" .Have a look at the Hifi High End Scene. They have (well respected) Remakes of almost every Tube you can Imagine. Of course it s a bigger Market but without the Power(and Money) private People put into the Development and the Production ,nothing would have happen. I can understand that a Remake of a 2A3 or 300b Powertriode is a big Market but that doesn t explain why a Px25 ,Px4, 211,845  or other strange exotic Tubes are avaiible again today .It s the Love and Enthusiam from a few People that make this happen. i also can t Imagine why JJ makes a 6386 Remake and not a Vf 14 . Are there so many 670 or Ba6a to service out there that it is worth the Aktion? Or is there another application for this Valve , but as a vari Mu Tube in a Audiocompressor ?
Instead of talking a lot of unfriendly ,unproductiv,destructiv Statements about a Vf 14 Replacement ,People like Klaus or Tele Usa could put there Energy into something productiv. I was reading somewhere that even the original Filamentwire and Blueprints for the Tube is bunkered somewhere. But what do they do ? Just put a 408a in a Steelbody and sell it for big Bugs . Of course it s not very easy to produce a good Remake but it s possible ,if there would be the Will. I am sure that one of the so called Mic Gurus could collect the nesserary  3 or 5 Million Buck s from a Investor ,like a famous and rich Artist ,to make it happen. Maybee not in a Stellhousing ( nobody has the Tools anymore, or is willing to blow 170 k A at 70 Volt for the welding  Process) but in a Glasshousing placed in a Steelcontainer. I think it s possible to reach the high Insulation between the Electrodes ,the low Gridcurrent , low Rp  etc ,if the design Destination would go into this Direction .
Sorry , i don t want to sound arrogant or negative and i am not in the Position to  ask for anything but all this " it s not possible " is annoing and not true. A lot of Experts used to say that the new production Tubes doesn t work and now we have 6072 and other Remakes that are even less noisy than the old ones. I personally prefer also vintage Tubes but if we don t have enough Vf14,Ac701 left for building new Mics there is no other Way than building new One s, i think. Or a good Fet Design like the one Frederic is working on and what would be  avaiable for non 47 Owners.
For my next 47 style Mic I am going to try 2 uf 80 (19Volt at 100 mA Heaters) in Parallel with series Heaters ,or  a 6cw4 Nuvistor with a seperate Heater.
Thank s again for all Your nice Work !
Greetings
Lothar

 

[granger.frederic]

the body shape, the xlr output etc means nothing at all...

and i think that the only way to know is to buy one and then dismantle it.(but i'll pass...)

i've never understood why so much hate against solid state ,nuvistores and op-amp

there are bad tube mics and bad fet mics and vice versa

if it sounds good, then what's the problem...?

@ lothar,
thanks for your friendly and clever post
i couldn't write better words

ps: uf80 19v 100ma you could use a single tube , the voltage drop should produce an acceptable amount of heat inside the mic body
good luck for you project
Cheers
Fred

 

[salomonander]

hmmm i am no expert but i had the grosser u47 with fet replacement and it didn't even sound like a tube mic at all. it behaved totally different. it sounded much closer to my u87 than to any of my tube neumanns. they all have a signature sound that was completely lacking in the emulation. 
i dont think that its possible to emulate a vf14. if grosser doesnt get it right i doubt that anyone will honestly.

I can tell opposite opinion. I have VF14EF and VF14 for my U47. I can't find "it behaves totally different" . There is a little difference in high end ( VF14EF is a bit more clear and opened), and a little difference in low middle (VF14EF is more leaner and dry). On loud sources VF14EF has less k3 . There is no similarity to U87 at all!! Fet replacement is very good substitute for daily work ( not for purists).

Fred, NU47 is tube project. As far as I know, NU47 contains EF14. I can hear huge difference in sound with U47.

hey omisha
we all have different ears i guess. i wasn't talking about frequency response tough, but the way the mic interacts with the source. the speed, saturation and general feel. all my tube neumanns - or better saying - all tube mics i own react in a similar way. they are -to my ears- very different from transformer based designs and this has nothing to do with their frequency response. the way the grosser handled the source reminded me a lot more of my u87 (modded by him than any other tube mic. to me the saturation sounded very transistor like. it sounded great though!

 

[o3misha]

hey omisha
we all have different ears i guess. i wasn't talking about frequency response tough, but the way the mic interacts with the source. the speed, saturation and general feel. all my tube neumanns - or better saying - all tube mics i own react in a similar way. they are -to my ears- very different from transformer based designs and this has nothing to do with their frequency response. the way the grosser handled the source reminded me a lot more of my u87 (modded by him than any other tube mic. to me the saturation sounded very transistor like. it sounded great though!

There is huge difference in presence , low middle, compression between U87 and Voxorama. All other nuances so much less noticeable, that I can not distinguish them. Scheme by which built the VF14EF Andreas is very difficult - much more complex than U87.  On Gearslutz was a huge test Voxorama with VF14, VF14EF and ER including U87. So many guys listened the files and nobody said that U87 even close to Voxorama fet. You are the first guy , who said this to me. I am surprised.

 

[tubestation]

Hello Solomonander,
Please compare a unmodded 87 to the Subject. I don t know what Mister Grosser did with your Mic. Would be interesting to get some Details. I know that Andreas helped one Guy to mod his U 87ai to sound like 67 . Better said it was a Master Thesis at the End of a Study what examined if it is possible to emulate the Sound of the 67 with solid state Electronics. The conclusion was that at low Levels it sounded similar,very similar but at loud Levels the saturation and Distortion changed . I personal didn t join the listening Sessions but more than 20 pro Audio Ears said all the same. I was told that the cost for the Parts where  only 2 Bucks  and only a few things where changed. Must have something to do with the concept of how the Fet is biased. No additional active Parts are involved, the Tranny wasn t changed. Maybee a Diode was used and a few Resistor where changed,but I really don t know, didn t saw any Schematics. Maybee Andreas did something similar to your U87. Over the Years I used several 87 of all kind and none of them sounded like a 47 fitted with the  Vf14 Fet Replacement that we had in the Studio. I agree with the Statement that at very loud Levels it sounded just a little bit like a solid State Mic, maybee like a Mv 691 (not 692) with a  Um 70 Head ,but not like a unmodded 87. But every Ear is different ........When You say that all other Tubemics you own sound different than a 47, i agree. You can t compare a Um57,Cmv , U 67 , M 49, a Thiele,Rft Octavia ,Sela Altec, or other vintage Tubemics with a 47.
Exactly this is the Problem and the Reason why People get so crazy raving about the 47.
Greetings
Lothar

 

[bockaudio]

I can tell opposite opinion. I have VF14EF and VF14 for my U47. I can't find "it behaves totally different" . There is a little difference in high end ( VF14EF is a bit more clear and opened), and a little difference in low middle (VF14EF is more leaner and dry). On loud sources VF14EF has less k3 . There is no similarity to U87 at all!! Fet replacement is very good substitute for daily work ( not for purists).

In the fine tuned world of U47's comparison to a U87 is silly.
The fet imitation VF14 you have, where you find little difference in sound with a real VF14, this is in an old mic, with an original Neumann psu?
If so, you and I would agree we hear, or listen for,  different things.

 

[bockaudio]

@ gus,
because Mr Bock from Bock Audio sells microphones,i wouldn't tell my opinion...

Selling microphones has nothing to do with being familiar with the sound of a U47. I know people who sell microphones who lack this familiarity, and I know engineers & studio owners who do not sell microphones who are familiar with the sound. NONE of the engineers I know, who KNOW what a U47 sounds like, would be fooled by the fet imitation VF14. Grammy winners, long noted careers etc  and the like.
Still no example of a tube effectively replacing a fet (in audio) has been provided.
But if I lived in pretendville, with Mr. Granger........

 

[granger.frederic]

No Mr Bock,
i don't think we live in the same world...
in your world there are things that are impossible, in mine we're working and try to make them possible...

ps:there's an elux251 on ebay since a couple of month...it's not the bustle ...!

http://www.ebay.com/itm/SOUNDELUX-ELUX-251-Muti-Pattern-Valve-Microphone-Telefunken-ELAM-251-USED-/371086583648?pt=UK_Sound_Vision_Other&hash=item56667be760

 

[o3misha]

@ gus,
because Mr Bock from Bock Audio sells microphones,i wouldn't tell my opinion...

Selling microphones has nothing to do with being familiar with the sound of a U47. I know people who sell microphones who lack this familiarity, and I know engineers & studio owners who do not sell microphones who are familiar with the sound. NONE of the engineers I know, who KNOW what a U47 sounds like, would be fooled by the fet imitation VF14. Grammy winners, long noted careers etc  and the like.
Still no example of a tube effectively replacing a fet (in audio) has been provided.
But if I lived in pretendville, with Mr. Granger........

I have 3 PSUs, and the original as well. My favorite - my own. With a tube rectifier (kenotron) instead of the original selenium rectifier. I hear a slight difference, believe me, between the transistor and a lamp. Another thing is that I'm not a purist. Important to me that with VF14EF I can work with loud sound sources with greater efficiency. Sound more transparent in the upper part of the spectrum. Sometimes it's better than VF14, which is more than 50 years old, it is not the best issue and quite small headroom, even when it was in his best form. There many engeneers in Europe ( two of them are my friends) who admitted that Fet design is fantastic replacement for U47. Nobody said that Fet is equal to tube. There many other  tasks that transistor replacement performs at least no worse than VF14s (which, by the way, all the sound differently, and not all good). For many engeneers, old, withered and lost elasticity PVC membrane sound better than new caps of Thiersch. So what? Whose opinion is assumed to be correct? What is the original sound if the microphones is 50 years old? I have met 10 U47s . Not one I would  want to buy. Only 11th and 12th I bought. And then, only after a serious overhaul. And again: it is almost impossible to find good VF14s today. There are many VF14s traveling between different owners. But most of them were used and are not in good condition or they are not even tested for microphone usage. And price is so big, that I don't want to use mic for every day.

 

[salomonander]

as far as i know andreas changed the fet to one that takes more beating and fine tuned the capsules voltage - or something like that he certainly did not try to make it sound like a tube mic.

off course its silly to compare a u47 to a u87. not really what i said though. i wrote that the grosser u47 reacted more like my u87 (or say my um70s or whatever fet mic i have around) than my tube mics. it was an all new clone with no original parts. a thiersch capsule, grosser fet  and haufe tranny.

but it just did not react like a tube mic at all. please notice that im talking about general response and not frequency response. frequency response is irrelevant to me as long as it is somewhat flat. i can eq any mics response to that of another mic. its about speed, saturation, compression and texture. its about getting close to the thing and interacting with it as a singer. and in this regard everybody who listened, felt that the grosser sounded like a fet mic. which is no big suprise since it is a fet mic it sounded like a very, very good fet mic though.

 

[ricardo]

Selling microphones has nothing to do with being familiar with the sound of a U47. I know people who sell microphones who lack this familiarity, and I know engineers & studio owners who do not sell microphones who are familiar with the sound. NONE of the engineers I know, who KNOW what a U47 sounds like, would be fooled by the fet imitation VF14. Grammy winners, long noted careers etc  and the like.
Still no example of a tube effectively replacing a fet (in audio) has been provided.

In 37 years of pro studio/tech life I can tell you I can only rely on my experiences, not group think.
I have had it in my hands, and my question remains, as there is no way you can call that fet imitation  EVEN  CLOSE to the real thing. Not even close. They look similar, that's it.
They are similar only in pretendville.

What do YOU think prevents a solid state mike from sounding like a good tube mike?

What are the technical issues?  What are the sonic issues?

Mr. Bock, how about giving us your views on why this is difficult .. as an experienced mike designer?

 

[tubestation]

Hello solomonander, i didn t want to continiue the "Transistor Sound" Discussion but
I can read german and was just studying the Voxorama Webside, so i couldn t hesitate.
1) Mister Grosser defenetly praise his Mic to sound exactly like a real 47.just with less Noise and without  the "Klirr"from the Tube.  Every Part of the Mic including the Powersupply is 100% exchangeable with the real Thing.
2) he sells his Vf 14ef as-  citation:  " soundwise there no notiable Difference to a Vf14 "
It s just what I was reading ,not my Opinion. I already said what I think about the Emulation.
Is it all fraud and Marketing only ,or is this 47 Clone worth the 4900 € excluding Taxes? A lot of People think so ,obviously.      and not only "Village People ". Again, not my Opinion but what i was reading on his Webside .
Greetings
Lothar.

 

[granger.frederic]

as i said before, in a u47 , the headamp is 20% of the sound.

if we admit that there is a 10% variation between for example a true vf14 and another replacement, then we can make clones and record some music in peace.

As far as i'm concern, i spend most of my time to find some good capsules because it's 80% of the sound.

this is what i've found:

for u47, Neumann still produce the k49, and it's worth the price....
M7 Thiersch and K47 Flea skinned by Thiersch are not my cup of tea ...too colored in the mids for me
Nor the M7 beesneez (too dark) : K7 much better

keep in mind that quite big differences exist between identical capsules

i've tested recently a true VF14 during one week, and i can tell you that the differences are not that huge with ef14/13 and 13cw4
there are differences, YES it's true, but i keep in mind that if the singer moves of 10cm the difference is much bigger...
In a full mix it's almost undistinguishable...
that's why i'm still experimenting (for the fun) for a usable solid state replacement, but i must admit that i already have some very usable solution with EF13/14 and 13cw4
i'll post here my schematic as soon as possible...

cheers

 

[Melodeath00]

granger, have you directly compared the Neumann K49 with the BeesNeez K7? I've been quite happy with my K7, but never used a genuine K47/49

 

[granger.frederic]

Yes i have,

my K7 has a softer, mellower sound, a lot of low end/low mids, a bit shy in the highs (but no sibilance at all), it sounds more like an m7 but it's a bit colored (simplifies a bit the signal), however it's a very good and musical capsule for the price.

my Neumann K49 is one of the most neutral capsule that i have , very well balanced, more accurate on complex signal, it can sometimes become a bit hard with some sources (a bit sibilant) if you don't perfectly adjust the polarizing voltage for it or if you mismatch the electronic parts.
i have a vintage brass KK47 also, and the sound is really in the same ballpark, almost the same.

i've tested some various cheap chinese reproductions but even if it can sometimes sounds ok, the K47 identity is lost.

the choice will depend of what clone you're building
for a M49, a FET headamp, or a mic with a more open headbasket, i choose the k7
for a U47 i choose the K49
but keep in mind that if you want the real Neumann sound , go with the K49, the K7 has its own character.

cheers
Fred