D-EF47 Tribute To Oliver Archut U47 Build Thread.

[Spencerleehorton]

Inside

 

[Spencerleehorton]

Inside 2

 

[poctop]

Almost there,

Best,
Dan,

 

[poctop]

Pictorial.

Best,
DAn,

 

[poctop]

Hi All, Just finished Final Testing this microphone,  Everything Works as expected and I am incredibly happy with the sounds of this microphone  ,  Many thanks To Oliver for this Awesome Creation.
and one of the most impressive thing not to say the least  this microphone is Incredibly QUIET with this Ef800 Telefunken tube in it ,
This kit will b able to Drive Ef800 , eF802 and Ef80 Telefunken tubes 
Absolutely Love it.

I am opening the Kit to the DIY community as we speak,  there is some minor Adjustemet I had to do with the PSU resistance Value
there is notes on the Shared mouser BOM about Those changes.

B+
R2 = 6.8ohm 3W
R6  = 4.7 ohm 3W
R11 = 4.7 ohm 3W

H+
R1 = 20K 2W
R3  = 20K 2W
R8 = 25K pot.

The BOM do not contains the Reed Switch but are available at those location ,

the PCB is designed to support these 2 Reed Relay 24V and 48V, Only one resistor is specifically used on the psu for 24V or 48V relay. Notes are in the BOM as well,  Rcoil Relay on the Psu denotes the resistance for either 24V operation or 48V operation.


RS Stock No. 291-9631 Brand RS Mfr. Part No. B48-1A72-BV631 RoHS Status Compliant Catalogue page 1186 Customer reviews (0) Add a review

http://uk.rs-online.com/web/p/reed-relays/2919631/

http://www.digikey.ca/product-search/en?vendor=0keywords=7101-24-1010 Relay Coto PN 7101-24-1010


The Silk Screen will be corrected on the next Batch if Any,

The PCB was specifically design to have package for AMI BV08 Classic Series and AMI T47 Transformer ,
Other transformer can be fitted as well.  Here is the 2 Mounting Strategies that will permit the Use of about any transformer.

https://cdn.groupbuilder.com/groupdiy/u/39511/58d028199435c.zip

could not be happier with this Toy,
Thanks Oliver.

Hope you will enjoy,
Best,
Dan,

 

[bernbrue]

Just ordered 2 kits. Thanks a lot, Dan!
Bernd

 

[poctop]

Just ordered 2 kits. Thanks a lot, Dan!
Bernd

Thanks Bernd,
Enjoy, 8) 
Best,
Dan,

 

[kidvybes]

...would I be correct in assuming this mic will work with a standard PSU design like the Zayance?...

 

[poctop]

...would I be correct in assuming this mic will work with a standard PSU design like the Zayance?...

it is not the U47 single supply Line Style like the one from Zayance ,

B+ has its Own , and H+ as its own ,

Fully Passive Split Choke Design, dual supply,

it is actually a Passive2469 PSU with special Feature for this Mic,

Best,
Dan,

 

[tommypiper]

Dany, great project.  But for this project, what about availability of the BV08 transformers? Now that Oliver is passed away and his partners are trying to catch up?  The future may be a bit uncertain about the transformers... ???

Also, on the AMI site it mentions the BV8R as the one to use for the EF800 tube, but your pictures are showing the BV08.  Can we use either transformer?

Are they available anywhere right now? 

I don't want to use the high nickel Cinemag, but if there are other alternatives let me know, thanks.

 

[poctop]

Dany, great project.  But for this project, what about availability of the BV08 transformers? Now that Oliver is passed away and his partners are trying to catch up?  The future may be a bit uncertain about the transformers... ???

Also, on the AMI site it mentions the BV8R as the one to use for the EF800 tube, but your pictures are showing the BV08.  Can we use either transformer?

Are they available anywhere right now? 

I don't want to use the high nickel Cinemag, but if there are other alternatives let me know, thanks.

Also, on the AMI site it mentions the BV8R as the one to use for the EF800 tube, but your pictures are showing the BV08.  Can we use either transformer?

the Bv08 classic series did not exist when this was done, as far as the future of AMI I am trying to help them as much as possible, there is no better way of helping them endorsing their transformer  because they really sound great.

if you wish , you can use any transformer you would like bv8 Style ratio , Other transformer will be able to be mounted with the pcb backwards mounting style. incredible what a Tie-Wrap Can do when properly fixed 8)

Best,
dAn ,

 

[poctop]

Here is the tubes datasheet for this project,

https://cdn.groupbuilder.com/groupdiy/u/39511/58d1402a07d5b.pdf
https://cdn.groupbuilder.com/groupdiy/u/39511/58d1402a0710a.pdf
https://cdn.groupbuilder.com/groupdiy/u/39511/58d028199437f.pdf

 

[poctop]

Added Mic Schemo with reference voltage 
Best,
Dan,

 

[Melodeath00]

I see you're underheating the tube at 5.2V. Was this Oliver's suggestion?

 

[poctop]

I see you're underheating the tube at 5.2V. Was this Oliver's suggestion?

Absolutely,
Best,
DAn,

 

[Melodeath00]

Interesting! I have his PSU and by default mine wound up underheating at 5.67V. I'm still not sure if the PSU has a built in trim pot - I am a bit of a newb still haha. If it didn't I was planning to make a modification that would allow me to adjust it, but again, I don't know specifically how I would do that.

 

[poctop]

Interesting! I have his PSU and by default mine wound up underheating at 5.67V. I'm still not sure if the PSU has a built in trim pot - I am a bit of a newb still haha. If it didn't I was planning to make a modification that would allow me to adjust it, but again, I don't know specifically how I would do that.

there is a trimpot on oliver PSU IIrC,
Best,
DAn,

 

[Melodeath00]

Thanks, Dan. By the way, do you know what the difference is between the BV8R and the Classic Series BV08? Is it just the appearance?

 

[Spencerleehorton]

Hi all,

Got my D-EF47 going finally!! Sounds amazing, gotta thank dany for putting up with my endless stupid questions and general dumbness!!!!
A while ago I have made 4 of my own U47 based on the Oliver schematics and this one sounds so much better.

Much more gain and precision in the sound.

This is the best sounding U47 circuit I've heard.

Just need to finish the nickel plating and I will post up some finished pictures.

Regards

Spence.

 

[Pip]

Hi all,

Got my D-EF47 going finally!! Sounds amazing, gotta thank dany for putting up with my endless stupid questions and general dumbness!!!!
A while ago I have made 4 of my own U47 based on the Oliver schematics and this one sounds so much better.

Much more gain and precision in the sound.

This is the best sounding U47 circuit I've heard.

Just need to finish the nickel plating and I will post up some finished pictures.

Regards

Spence.

Can you give some sound files as a shoot out? How many others "have you heard" and short of whos they were what are the differences? Rather pregnant statement is all.

Good luck with the plating.