Advice for building a U47 clone

[ElSmurf]

My DIY U67 is (to me) my most versatile vocal mic and a great instrument mic. My DIY C12 (to me) is my most versatile instrument mic and a great vocal mic. My favourite vocal mic is my DIY M49b with a Beesneez M7. My DIY EF-U47 (Arienne Flat K47, previously Beesneez K7) is great, and has a certain front of mix pop sound, but it doesn't excel as often as the M49 and isn't as versatile as the U67/C12.

Thanks for this! Makes me want to start building a D49 with Arienne's K49 even more!

 

[Eike]

+1 on most of what's been said here. Dany's EF-47, Arienne flat K47, Moby BV-08. That way you'll probably have more work with the PSU than the mic itself, which is a good thing IMHO. And end up with a killer tube mic.

EF-47 with one tube and a more complicated PSU or or D-47 with two tubes and a simpler PSU?

 

[tonycamp]

Anyone compare the Arienne's K47 to the Thiersch red or blueline in their 47?

 

[Accelerator]

Well…

If I remember well there is the Danny’s poctop

D-47 Tube Mic Kit DIY Solution

https://groupdiy.com/threads/d-47-tube-mic-kit-diy-solution.68023/

In which D-47 Tube Mic Kit you will have 5 deferent option (VF14, EF12, Tween 408-A, EF800, EF14) choices about the tubes, for the valve that you like to choose…

Also, if money is not an object, the Slovakian Flea Pro Audio others their Flea47 mechanical kit that you will have 3 deferent option (VF14, EF12, EF14) choices about the tubes for the valve that you like to choose…

Flea47 Kit & Parts

https://www.flea-microphones.com/parts/flea47-kit-parts/

Now, in every tube - capsule – transformer choice that you will make, you will have several pros and cons, so it is clearly up to you, your preferences and your needs the decisions and the directions that you set up about your “U-47” building…

For instants:

If you are looking for the most “old, vintage & authentic” Neumann U-47 “male voice only” timbre of voicing for your sound, then the EF12, EF14 and also the pear of Tween 408-A valves at 105 Volts with a Thiersch Elektroakustik M-7 PVC film (Polyvynylchlorid) STW7 blue line and a Haufe BV8 Microphone audio transformer, or a Moby Transformers for Neumann ~ BV.08 (U47, U48) Ratio 6.5-1 will be the better choices, but for the pear of Tween 408-A valves you will have to deal with a lot of heat, the EF14 tube is very expensive and also the EF12 tube doesn’t “match” perfectly for the BV.08 at 200Ω Output, so you may have to connect the Output Transformer at 50Ω Output…

But...

If you are looking for the most “modern & versatility All around” U-47 timbre of voicing for your sound, with a microphone that will allows you to use it for male & female voices and also for instruments, then the Oliver Archut U47 Alternative Microphone with EF-800 Tube at 120 Volts with Remote Polarity Switch on Power Supply Unit, with Thiersch elektroakustik M-7 PET-film (Polyester) STW7.1 red line or even the Arienne Audio Flat K47 capsule and a CineMag CM-2461NiCo Tube Microphone Output Transformer 6.5-1 will be the better choices…

From there on the “sky is the limit” about the designing of your power supply unit and just for “food for thoughts” I post these very useful articles about this DIY U-47 type of microphone, of the Croatian Moxtone Labs…

A JOURNEY INTO THE LEGEND: THE U47

http://www.moxtone.com/mU47_U47.html

A JOURNEY INTO THE LEGEND: THE U47 POWER SUPPLY

http://www.moxtone.com/mU47_U47_part2.html

A JOURNEY INTO THE LEGEND: THE OUTPUT CHARACTERISTICS OF THE VF 14 AND ITS SUBSTITUTES

http://www.moxtone.com/mU47_U47_part3.html

 

[ElSmurf]

Anyone compare the Arienne's K47 to the Thiersch red or blueline in their 47?

I have no experience with the Thiersch capsules, but I used to have the 3U M7 in my D-EF47. Swapping that out with the flat K47 was a big step upward in every way.

 

[ElSmurf]

EF-47 with one tube and a more complicated PSU or or D-47 with two tubes and a simpler PSU?

You can't go wrong either way. And even tho the PSU PCB for the D47 is simpler, you'll still have to build your own PSU with the choke etc. I don't think there'll be much difference in amount of work or difficulty between the two.

 

[Khron]

you'll still have to build your own PSU with the choke etc.

And what's so magical about that supply?

 

[garp]

Nothing else than beeing the original design ! In the "Maison de la Radio" ORTF techs always said "everything is in the signal path even the PSU" . I agree that this design looks weird and defies logic but again it was made like that and certainly with some intend behind. At these time Neumann factories employed very skilled engineers and had some excellent industrial plants, so if i want a U47 clone i'll follow their rules, @Khron if i decide to go other ways it's not a U47 anymore, and as i said maybe a better microphone to your ears , but the thread is about building a U47 clone, nothing else.

 

[Khron]

Nothing else than beeing the original design ! In the "Maison de la Radio" ORTF techs always said "everything is in the signal path even the PSU" . I agree that this design looks weird and defies logic but again it was made like that and certainly with some intend behind. At these time Neumann factories employed very skilled engineers and had some excellent industrial plants, so if i want a U47 clone i'll follow their rules, @Khron if i decide to go other ways it's not a U47 anymore, and as i said maybe a better microphone to your ears , but the thread is about building a U47 clone, nothing else.

Fine, sorry i tried to bring an element of rationality to the discussion; not that my question was aimed at you anyway...

No doubt they had good engineers, but perhaps more than that, those engineers did what their bosses told them to do. Oh, oops, there i went with the rationality again...

And yes, part of the intent was the ability for the mic to work off of 105V worth of batteries (as well), in addition to mains. But sure, if you wanna see those as "rules", you do you

 

[tomas.borgstrom]

The power supply does affect the sound of not only microphones but audio in general.

It’s of course extremely less important than capsule, tube, transformer, body.

 

[tomas.borgstrom]

I have no experience with the Thiersch capsules, but I used to have the 3U M7 in my D-EF47. Swapping that out with the flat K47 was a big step upward in every way.

Anyone compare the Arienne's K47 to the Thiersch red or blueline in their 47?

Theirsch blue line neither sound like Neumann nor Gefell M7. It’s too soft. Red line is different as well but a better match. 3U M7 has the right timbre but the sound quality is inferior. I’m curious how it would sound reskinned by some of the best.

Arienne K47flat is a great match but has it’s own sound. I’m not so fond of K47/K49 in combination with the U47 circuit.

 

[garp]

For me the flaws and defaults in a design are part of the sound we are all seeking here , same as the Minimoog that "suffers" from serious fault in the filter design but without this fault it is not a minimmog anymore, same thing for my VCS3 that i cloned 2 times (one buffered with moden components and the other one "original" unbeffered matrix and original transistors). Two different beasts and none has the charm of the original despite beeing very clean and punchy.

 

[Accelerator]

And what's so magical about that supply?

There is nothing “magical” in the original Telefunken-Neumann’s U-47-N Power Supply...
Actually the Telefunken-Neumann’s U-47-N Power Supply it was just a mare “cut corners” option product of a ruined –after WW2…- Germany…

Even the 1933’s Neumann CVM-3 (the famous “Adolf Hitler’s bottle mic.”...) had separated HT (100 Volts) and LT (4 Volts) voltages to power up the RE086 tube…

Does the Telefunken-Neumann’s U-47-N Power Supply affect the operation & the sound, of not only the U-47 microphone system but audio in general?...
Yes, it does...
Is there in this Telefunken-Neumann’s U-47-N mare “cut corners” Power Supply design any "magic"?...
The "Affocionados" will says to you "Yes", the "Technocrats" will says to you "No"...

 

[Khron]

There is nothing “magical” in the original Telefunken-Neumann’s U-47-N Power Supply...
Actually the Telefunken-Neumann’s U-47-N Power Supply it was just a mare “cut corners” option product of a ruined –after WW2…- Germany…

Even the 1933’s Neumann CVM-3 (the famous “Adolf Hitler’s bottle mic.”...) had separated HT (100 Volts) and LT (4 Volts) voltages to power up the RE086 tube…

Does the Telefunken-Neumann’s U-47-N Power Supply affect the operation & the sound, of not only the U-47 microphone system but audio in general?...
Yes, it does...
Is there in this Telefunken-Neumann’s U-47-N mare “cut corners” Power Supply design any "magic"?...
The "Affocionados" will says to you "Yes", the "Technocrats" will says to you "No"...

Thank you...

 

[Accelerator]

Theirsch blue line neither sound like Neumann nor Gefell M7. It’s too soft. Red line is different as well but a better match.

"Trush for one ~ Treasure for the other..."
For the same reasons that you report about for the Thiersch Elektroakustik M-7 PVC film (Polyvynylchlorid) STW7 blue line to be sooooo sugar-lly & sooooo velvet-lly "soooooft" I will prefered over the Thiersch elektroakustik M-7 PET-film (Polyester) STW7.1 red line, if I had to make a DIY U-47 for mostly male and maybe for same female voices for some lovely & velvet-lly Jazz Standards songs

 

[garp]

Did someone ever said "magical" here ? Hummmm maybe someone made a big ugly straw man ! I promise next time i am offered a dirty vintage U47 i'll throw away this obsolete tube, change this brittle pvc M7 and replace this ugly PSU for a modern regulated stabilized one .... I promise ... or maybe not !!! .)

 

[Khron]

Did someone ever said "magical" here ? Hummmm maybe someone made a big ugly straw man ! I

Once again, my initial question was not aimed at you. My apologies for the lack of clarity on that one.

And i thought we were talking "clones" anyway..? Nowhere did i mention "resale value of an original unit"...

 

[garp]

I totally agree with you but if you want to clone a citroen mehari (classic vintage plastic car) and replace the ugly flat 2cylinder air cooled with an american V8, is it still a Mehari ? This question is debated for centuries in the famous Ulysses's ship paradox (private joke)

 

[Khron]

I totally agree with you but if you want to clone a citroen mehari (classic vintage plastic car) and replace the ugly flat 2cylinder air cooled with an american V8, is it still a Mehari ? This question is debated for centuries in the famous Ulysses's ship paradox (private joke)

Well you can't really get the original engine anymore anyway (VF14M), so how much performance and/or comfort would an original fuel tank add?

A power supply is a power supply - as long as ripple & noise are low enough, and impedance is low enough within the audio range, it shouldn't matter WHERE that DC comes from (barring any ground loops that might occur in a mains-powered supply, of course). The mic sure as hell won't care - it has no conscience, no memory and no opinions.

 

[Delta Sigma]

Theirsch blue line neither sound like Neumann nor Gefell M7. It’s too soft. Red line is different as well but a better match. 3U M7 has the right timbre but the sound quality is inferior. I’m curious how it would sound reskinned by some of the best.

Arienne K47flat is a great match but has it’s own sound. I’m not so fond of K47/K49 in combination with the U47 circuit.

I had a Beesneez K7 in my U47 clone. It sounded fantastic when it worked well with the source, but it didn't work too often. I realize now that I very much prefer the M7 sound. I have an Arienne Flat 47 in my U47 now. Works on nearly everything.

For most vocals though, I prefer my M49 clone with a Beesneez M7.