Neumann U 47 Clone - A DIY Bachelor Thesis

[Zottel]

Here is the answer from BSA Microphones:
"Thanks for your mail, and very interesting project .

Indeed, the Haufe would be an excellent choice. Unfortunately we don't sell them separately, but you should contact Andreas Grosser directly by mail  to see if you can purchase a single unit. If he's available, he should get back to you very quickly.

Sorry we couldn't be of more assistance, but if ever there's anything else or if you have any questions, please feel free."


I hope Andreas is answering next week Let's see!  8)

 

[Zottel]

Hey Folks!

Group DIY is up again! Fine!

I called Andreas last week he's a fine guy But he's talking very fast! So next time I'll take a microphone and record the stuff he's saying  ;D

Back to topic:

BV08
Andreas told me that i could buy the Haufe BV08 directly from him
Just for info: The Haufe BV08 is attached with 4 screws. So it will not fit to the flea U47 kit. If you still like to use the Haufe BV08 you could ask Andreas. He has an extra "adapter" to solve this problem.

VH14ef.
If you send your DIY microphone to Andreas so he can check all the measurements like anode voltage, klirr factor, etc. he'd sell you a VH14ef. But all of his high standards have to be achieved ! So let's see if i can work on this high standards

I think i will go with these part's: Not sure about the PSU. Get it from Andreas or build it on my own?  ???

 

[o3misha]

Thats what I told you about AG. Congrats! 8)

 

[Zottel]

Yes Sir! Thanks for that  8) .

I'm very interrested in how this thing might turn out!

 

[Zottel]

Hey-didely-ho! 

I'm back at the office and ordering all the part's I'll need While I'm doing this I'm thinking about some things:

1. Any thoughts about microphone cables? A decent Sommer 7 pin would be a good start right?
2. Back in the day electrical parts used to be soldered with a different kind of soldering tin. I don’t have to think about this because it wont have any impact on the sound right?
3. Also the electrical Components where made in a different kind of way. Resistors etc. Do I have to search for some old parts?  ???
4 As long as I'm waiting for all the parts to arrive I'm thinking about books and stuff to prove my writings in my bachelor thesis.
Does anybody know any good readings in building microphones, Neumann, the U47, that I have to check out? 

Kind regards,
Max. 

 

[chefducuisine]

1. Sommer Octave Tube - available at Thomann. I like the flexibility of this one. Alternatively Gotham GAC-7.
2. For my own projects I still use leaded tin until my stock ceases - hopefully there is better stuff around compared to the actually used lead-free tin... from my day job I know all the problems lead free tin can give you in terms of long-term robustness.
3. For Resistors get Metall-Film (Mouser is your friend for the high-ohmic ones). Capacitors are a different story: The 0,5 uF coupling cap for example should be a PIO or you'll check if you can find on of the old Bosch as seen in the original. The Capacitors in the high ohmic section of the U47 should be Styroflex. For the Power Supply you can use whatever Electrolytic you like (I recommend Panasonics FC or FR series). Look for the 105°C types of Electrolytics. They'll last longer...
4. I am not aware of a microphone building book.
For HQ microphones and their principles you should check these freebies:
www.neumann.com/download.php?download=docu0003.PDF
www.schoeps.de/documents/Mikrofonbuch_komplett.pdf
The official Neumann Book from PPV is also an interesting read, but for 60 EUR I wouldn't buy it again as it could go deeper here and there.

...hope this helps.

 

[Zottel]

So let's say this one?
http://www.ebay.de/itm/Kondensator-Bosch-MP-1-F-250-Volt-/331662918750

But it say's 250 Volt. Is this a problem?

 

[chefducuisine]

Oooops I made a mistake - the coupling cap is a 0,5 uF.
I corrected this in my previous response.

For a first step I would go with Wima MKP Series or similar. The modern equivalent capacity is 470nF.
When your mic is working you can change it to a more exotic one.
Voltage rating should be 160 V DC or higher as long as it fits mechanically.

Did you decide on what Tube you are going to use?

 

[Zottel]

Hello I'm going to use the tube from Grosser

Okay good idead to use new elements, get it working and switch the parts later on.

 

[Phrazemaster]

Hello I'm going to use the tube from Grosser

Okay good idead to use new elements, get it working and switch the parts later on.

So you are going to send the microphone to him then? As far as I know, he only sells his VF14EF or VF14ER if he services a mic himself...

 

[Zottel]

Yes

He lives ~ 100 km away from me so it's not a problem 

 

[Zottel]

Hey folks,

Does anybody know how long these parts have been in the old U47?

Tiersch offers them in 3 diffrent lengths. 

And also another problem occurred. I ordered the Body from this nice guy:
http://groupdiy.com/index.php?topic=58609.0

All nice and fine but It has a two rail mounting system for pcb's!  In my dumb head I was thinking about building a point to point mic. There's nothing bad about PCB's but i dont think the VF14 tube will fit into the mic body when a PCB is inserted.
Are there any PCB's for the 2 Rail mounting system that allow a big *** tube like the VF14?

 

[Phrazemaster]

If I recall correctly, 58mm is the correct height.

I don't know of any U47 PCBs that would work for a VF14.

You might ask the seller what people are using. Or get a different body.

Edit: for accuracy

 

[Phrazemaster]

Be sure to check out Max (IOaudio)'s body.  It's s 3-rail system.

 

[Andriejus]

I was told by Thierch that Neumann originally used 58 mm holder for U47.

Kind regards,
Andrew

 

[Zottel]

Thanks for your reply. Ordered the stuff from Tiersch

IOaudio run out of body's 
My time schedule is to short to wait untill he might start with a new run.
I'was thinking about AMI body's but they are a little to expensive for the rest of my budget.
So ill have to figure out something with the body of Anreju

 

[Phrazemaster]

Hey Zottel, I forgot to mention Max's MK47 PCB...2-rail...

 

[Zottel]

Yep i checked it out but i guess the vf14 from grosser wont fit.

So i think i will have to figure something out
I'm thinking about some small metal parts to mount this:

And i need a round metal plate that will hold the BV08.
(The lowest plate inside the body shown in the picture.)

 

[Andriejus]

Hi,

If you could give me the right measures I could make these two parts together with my other parts that I will be ordering next week for laser cutting..

Kind regards,
Andrew

 

[Pip]

That is not the right tube socket for a VF14 tube that looks like it would work for a EF80, 800, 801. It makes sense as Oliver Archut was very much of the mind that these where very suitable alternatives to the VF14.

What you want is a Y8A 10 pin socket: http://www.ebay.com/itm/150808605237?_trksid=p2060353.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT