Measured VF14 characteristic

[granger.frederic]

i'll try that but my focus is on a solid state VF14 emulation

If only someone with a big Spice experience ,could create a good model....

I've already tried but i've given up, as i'm not familiar enough with this software, and i miss some usefull datas like the triode mode.

Someone with a true VF14 and a good lab, could achieve that...

 

[marcus4audio]

There is another tube  - russian nuvistor 6S51N-V compared to VF14.
They look pretty similar.
6S51N has lower amplification (mu=26).

Hey, did you make some progress with your measurement? Some new "victims"? btw, I'm bit confused with your info about 6C51H-B gain. According to this (and few more data sheets)
http://tubes.ru/techinfo/NuvistorTubes/6c51n.html
6C51H has Gain coefficient 32±12 and 6C51H-B has 30±12. So, did you mixed them up? Which one of this two nuvistors are closer to the VF14 with gain?

 

[bockaudio]

i'll try that but my focus is on a solid state VF14 emulation

If only someone with a big Spice experience ,could create a good model....

I've already tried but i've given up, as i'm not familiar enough with this software, and i miss some usefull datas like the triode mode.

Someone with a true VF14 and a good lab, could achieve that...

Do you have a single example of a sand based emulation of any vacuum tube for audio, let alone the VF14?

 

[o3misha]

i'll try that but my focus is on a solid state VF14 emulation

If only someone with a big Spice experience ,could create a good model....

I've already tried but i've given up, as i'm not familiar enough with this software, and i miss some usefull datas like the triode mode.

Someone with a true VF14 and a good lab, could achieve that...

Do you have a single example of a sand based emulation of any vacuum tube for audio, let alone the VF14?

And who is interested in making the substitution for what exists? VF14 - extinct thing that is available to a very limited number of people, and even then in a very precarious condition, given the age of more than 55 years - hence the interest in the possibility to replace VF14 in U47.

 

[granger.frederic]

dear bockaudio,

for example a vf14Fet from A Grosser is a decent emulation if you read the tech forums...

A friend from another studio has given me a true VF14 for a week thus i can make some more accurate measurements (K2,K3...)

i'm actually working on a J305 in the first stage with promising results...

i'll post back asap

 

[o3misha]

Fred, For purists  substitutes doesn't work in U47. All what does not produce 100% VF14 sound is bullsh*t. I heard this opinion many times on Klaus's forum or on PRW. Very interesting to get  k2 and k3  distortions same with VF14 ...

 

[marcus4audio]

@Fred. Can you describe how you measure k2 and k3?

 

[granger.frederic]

very simple: you inject some test signals in the vf14 grid, then you analyse the output signal (after the bv8) with a spectrum analyser, after that if you want, you can remove the fundamental signal with a very narrow filter.Then you can measure the rms value of the remaining harmonics (plus noise...)
it's very interesting to test with various amplitudes and with some intermodulation

if you don't have an analyser : http://www.sillanumsoft.org/Download/SetupVA2014.02.exe

don't forget to test with a load of 1,5kOhms at the mic output

cheers
Fred

 

[marcus4audio]

very simple: you inject some test signals in the vf14 grid, then you analyse the output signal (after the bv8) with a spectrum analyser, after that if you want, you can remove the fundamental signal with a very narrow filter.Then you can measure the rms value of the remaining harmonics (plus noise...)
it's very interesting to test with various amplitudes and with some intermodulation

if you don't have an analyser : http://www.sillanumsoft.org/Download/SetupVA2014.02.exe

don't forget to test with a load of 1,5kOhms at the mic output

cheers
Fred

Thanks.

 

[bockaudio]

dear bockaudio,
for example a vf14Fet from A Grosser is a decent emulation if you read the tech forums...
i'll post back asap

I suppose that's the key. You think my reading about other's opinions and third hand experiences would mean something. 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.
IF one could realistically accomplish this, it would be implemented by mig mfg's like Fender et al.
Not saying it can never happen, it just hasn't yet, in realville.

 

[granger.frederic]

Dear Bock audio,

i think that your not aware of all the innovations in the microphone world...

another example:

https://www.youtube.com/watch?v=GPFcWUr_1m8

and especially : https://www.youtube.com/watch?v=9m0B1pKZRT4

i'm sorry that you haven't achieved a good emulation of the u47 circuit, but today "not even close" seems excessive to me...

 

[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.

 

[bockaudio]

Dear Bock audio,
i think that your not aware of all the innovations in the microphone world...
another example:
https://www.youtube.com/watch?v=GPFcWUr_1m8
and especially : https://www.youtube.com/watch?v=9m0B1pKZRT4
i'm sorry that you haven't achieved a good emulation of the u47 circuit, but today "not even close" seems excessive to me...

You are correct. I know very little about other brands. Please ignore anything I said on this subject.
Enjoy pretendville.

 

[ricardo]

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.
IF one could realistically accomplish this, it would be implemented by mig mfg's like Fender et al.
Not saying it can never happen, it just hasn't yet, in realville.

David, leaving aside guitars ...

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?

It would be good to have your views as a mike designer.

 

[Gus]

Dear Bock audio,

i think that your not aware of all the innovations in the microphone world...

another example:

https://www.youtube.com/watch?v=GPFcWUr_1m8

and especially : https://www.youtube.com/watch?v=9m0B1pKZRT4

i'm sorry that you haven't achieved a good emulation of the u47 circuit, but today "not even close" seems excessive to me...

Do you have any idea who you are responding to?

 

[o3misha]

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.

 

[granger.frederic]

@ gus,

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

this forum was not "a la KH" but if we are there, then it's a sad, sad world...

dear misha,

if we admit that when Mr Kantola says : "only actual parts" , he doesn't include the actual poor tube production, then Nu47 is solid state.
but i admit that i haven't seen the schematic.
however he says in the video that he doesn't use a german steel tube

Emulation is not, and probably never will, a perfect cloning. example : UAD2 stuff, daily usable but not perfect...

However, when you listen carefully to https://www.youtube.com/watch?v=9m0B1pKZRT4 and all the other shootouts, and if you admit that the recordings were done "all equal" , then you can honestly say that it's a VERY CLOSE re-creation of the U47 sound.
For me, better then all of the other tube clones that i have tested (Flea Ef12 M7,Wunder CM7gt M7, TFK U47 with vf14k and others...)

PS:for all who think that it's impossible to emulate the vf14, you're not forced to read this topic, or please add something useful ...

 

[o3misha]

@ gus,

if we admit that when Mr Kantola says : "only actual parts" , he doesn't include the actual poor tube production, then Nu47 is solid state.
but i admit that i haven't seen the schematic.
however he says in the video that he doesn't use a german steel tube

Emulation is not, and probably never will, a perfect cloning. example : UAD2 stuff, daily usable but not perfect...

However, when you listen carefully to https://www.youtube.com/watch?v=9m0B1pKZRT4 and all the other shootouts, and if you admit that the recordings were done "all equal" , then you can honestly say that it's a VERY CLOSE re-creation of the U47 sound.
For me, better then all of the other tube clones that i have tested (Flea Ef12 M7,Wunder CM7gt M7, TFK U47 with vf14k and others...)

PS:for all who think that it's impossible to emulate the vf14, you're not forced to read this topic, or please add something useful ...

Martin said: But I was using these old German steel tubes by Telefunken..

I think it is EF14. Sound is very close to EF14 for me. Agressive, with dried low middle area. Nu47,-good clone. But I prefer Flea or Wagner. Also Voxorama.

 

[Gus]

@ gus,

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

this forum was not "a la KH" but if we are there, then it's a sad, sad world...

Look at what links you posted, look at the body of the microphone.  I don't think it is solid state
 
I have working on solid state,  tube, solid state and tube, transformer and transformerless microphone designs.  I am taking a break because I was at the next stage, buying and building audio measurement devices. This will cost a good deal of money and unless I sell microphones I don't think I will do this.  I have worked with simple solid state designs one design was perceived as a tube microphone in a microphone comparison in a studio. 
It had a 6072a microphone like sound
Anyway why not design a solid state microphone for the best use of the solid state device(s)

To do any microphone design you need to think about every thing in the microphone and its interaction with the devices after it.

 

[Melodeath00]

@ gus,

if we admit that when Mr Kantola says : "only actual parts" , he doesn't include the actual poor tube production, then Nu47 is solid state.
but i admit that i haven't seen the schematic.
however he says in the video that he doesn't use a german steel tube

Emulation is not, and probably never will, a perfect cloning. example : UAD2 stuff, daily usable but not perfect...

However, when you listen carefully to https://www.youtube.com/watch?v=9m0B1pKZRT4 and all the other shootouts, and if you admit that the recordings were done "all equal" , then you can honestly say that it's a VERY CLOSE re-creation of the U47 sound.
For me, better then all of the other tube clones that i have tested (Flea Ef12 M7,Wunder CM7gt M7, TFK U47 with vf14k and others...)

PS:for all who think that it's impossible to emulate the vf14, you're not forced to read this topic, or please add something useful ...

Martin said: But I was using these old German steel tubes by Telefunken..

I think it is EF14. Sound is very close to EF14 for me. Agressive, with dried low middle area. Nu47,-good clone. But I prefer Flea or Wagner. Also Voxorama.

Actually, when Martin says "but I was using these old German steel tubes," he is implying that he used them in his old designs, but not in this new design. In fact, he is using "all new parts" for this one, which is why it is so exciting for him. No more "rejecting 8 out of 10" steel tubes.