D-EF47 Tribute To Oliver Archut U47 Build Thread.

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hugo said:
Hi, i received the mouser cart, but the 14k resistor of psu is 1/2w, instead of 1w writed on the pcb...is it still safe to use it , or should i order one 14k 1w ?
Regards,
Hugo
up...if somebody can tell me if 1/2w is enough...it is not for the price of one resistor, just because i would like to have the cleanest board possible...
 
hugo said:
up...if somebody can tell me if 1/2w is enough...it is not for the price of one resistor, just because i would like to have the cleanest board possible...

Yes 1/2 W will be fine ,
Best,
Dan,
 
I finally finished mine today!  AMI T47 transformer, Telefunken EF800 tube, Peluso P-K47 capsule.... Sounds huge and so quiet!  Impressive to say the least. 
 
I'm currently building the d-ef47 circuit & just checking if there's any paperwork showing the wiring/pin out for the 7 pin connector & where the pins connect to the circuit board?
 
So I found Oliver's schematic which shows the pin out as:
Pin 1 audio
Pin 2 audio
Pin 3 B+
Pin 4 ground
Pin 5 0v
Pin 6 H+
Pin 7 pattern switch

Does this look correct? Which of pins 1 & 2 are + or -? What does pin 5 connect to?
 
Mjwever said:
So I found Oliver's schematic which shows the pin out as:
Pin 1 audio
Pin 2 audio
Pin 3 B+
Pin 4 ground
Pin 5 0v
Pin 6 H+
Pin 7 pattern switch

Does this look correct? Which of pins 1 & 2 are + or -? What does pin 5 connect to?

See post #78 in this thread for a diagram (page 4).

C
 
Thanks for that. I had read through the thread before but couldn't see any of the pic's/diagrams. I just switched browser & now i can see what you are referring to. One more question - does pin 3 connect to the same ground as marked on the circuit board as pin 7?
 
I've just spoken to supplier and can do the U47 transformer 5887 pcb version or with leads for £70 + p&p, if there was a group buy of above 30-40 this price could be £50 + p&p each, just thought I'd let you all know.

Regards

Spence.
 
Does C2 and C3 need to be the same type, or just the specs are important ?
thank you
 
Hey Everyone!

Excited to have finished this build!  I am really impressed with this U-47 circuit and love how it sounds on vocals with the combination of Dan's D7 capsule and the BV08C transformer.  It has a high end sparkle without an aggressive midrange presence and can handle dynamics without the harshness that I get with my U87AI. Dan's D7 capsule sounds absolutely incredible!  I have plans in the future (when more funds are available) to build this circuit again with a Thiersch blueline, but it will be for comparison sake and to have a slightly different flavor, but in my opinion, the D7 is lacking nothing and is the perfect solution for my needs for tracking vocals.  Could not be happier with this circuit.

Thanks to Dan and Oliver for making this possible for us!!!
 

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Hi, just finished my D-EF47 build …..but I have an problem. I need a lot of  gain 40-50db and I have loud microphonic effects. The signal is very noisy, very sensitive when knocking slightly on the body. I swapped the tubes, the Capsule, the Transformer. I double checked the Voltages (seems to be inside the tolerances…. poctob Mic schematics ),  measured the cable connection from Mic output until the XLR  checked the Groundings…….    seemed to be similar to snork7 problem but unfortunately  it was not the cable…  any suggestions .??? Thanks in advance
 
la-2a said:
Hi, just finished my D-EF47 build …..but I have an problem. I need a lot of  gain 40-50db and I have loud microphonic effects. The signal is very noisy, very sensitive when knocking slightly on the body. I swapped the tubes, the Capsule, the Transformer. I double checked the Voltages (seems to be inside the tolerances…. poctob Mic schematics ),  measured the cable connection from Mic output until the XLR  checked the Groundings…….    seemed to be similar to snork7 problem but unfortunately  it was not the cable…  any suggestions .??? Thanks in advance

Check the tube and the 10nf styro cap
 
@ TLRT ...OMG.!!!Problem solved.  Changed the 10nF Cap and all is fine now    :)    YES I LOVE THIS FORUM.!!
Thank you man ….you saved my day ..

best regards
 
Wanted to attach some sound files of my D-EF47 with Dan's D7 capsule to show off how awesome this mic is on vocals.  I chose the star-spangled banner since there is a wide dynamic range and because it is open source.  Bear in mind I am much much more of an engineer than a singer, so I apologize for the rough vocal performance, though I think you can get an idea of how the mic stacks up against another awesome mic (U87AI).  I've always found the U87 to be a bit harsh (but not unusable) on male vocalists who have any grit or air/breathiness in their voice.  With the U47, that problem is gone!

I do not own pairs of any nice pres, only singles, so I unfortunately had to use two of my  003's pres, but I think it highlights the differences pretty well.  The files were recorded in my home studio, which is semi treated.  Mic setup is what is seen in the picture.
There is no EQ, compression and I did my best to make the volumes equivalent. I apologize for the "p" sounds on the U47 -that is not the mic, it's because the pop filter I have is too small to cover both. 

https://www.dropbox.com/sh/tvlfqfnavpk57md/AABewubfOTYY0fl5QkyQ1kLEa?dl=0
 

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Hi,
I have 260v on the 220v terminals...how could i make this lower (if possible ?), or is it an issue in this circuitry ?
Thank you
 
Hey Hugo!

If you have ~270 AC at your toroidal before the PCB, then I think you are okay.  Wimmy and I both had that at our toroidals before we ran it through the rest of the circuit and everything checked out fine at calibration time.  I have not checked the terminals with it in the circuit, but was able to get H+ at 5.05V DC and B+ at 105V DC during calibration.
 
Yes, for some ears. A lot of people prefer them but there's no guarantee that you will. If you find some on ebay, buy them. Build your mic with Polypropylene film caps. Once you have your mic tweaked the way you like it, swap the output caps and see what you prefer.

A lot of people like metallized paper in mics as well.
 
Delta Sigma said:
Yes, for some ears. A lot of people prefer them but there's no guarantee that you will. If you find some on ebay, buy them. Build your mic with Polypropylene film caps. Once you have your mic tweaked the way you like it, swap the output caps and see what you prefer.

A lot of people like metallized paper in mics as well.

Thanks ! I took a pair of vintage green russian PIOs, will compare and will post my results here.
Regards,
H.
 
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