U47 inspired clone (Based on a Flea DIY Kit)

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chefducuisine

Well-known member
Joined
Aug 11, 2009
Messages
255
Location
Ulm - Germany
Hi,

here is my version of an U47 inspired clone attempt:


normal_U47_total_web_small.jpg


The whole thingy is based on a Flea DIY Kit with the following options:
- K47 capsule, skinned by Thiersch
- BV12 Trafo
- Chrome Grille
- Binder connector
- EF86 Socket
- U47 Type schockmount

The schematic is roughly based on Max's (ioaudio) MK7 because of the tube (EF86). Many thanks for the inspiration, Max!!! ;)
I have changed the polarization scheme to incorporate 9 steps on the power supply. :D

Please see my galery for more detailed pictures without the cover.
http://twin-x.com/groupdiy/thumbnails.php?album=454

The result is awsome. ...Sounds great! ...having a lot of fun currently. :p


Regards,

Chris
 
Love it Chris!

Have you put it through the ropes?  How's the sound? Let us know! :)

Cheers,
Marcos
 
Looks schliiick.  :)

WHeere did you get the PS enclosure?  (Looks like the face plate comes off so you were able to silk screen the graphics, where did you have that done?)
 
The mains transformer is custom made.

The PS PCB is based on Max's MK7 PS design with a regulated heater section based around an LM-317.
I did the layout myself. Because it is based on Max' design, I did not publish it.
As described above, the polarization scheme has been changed to incorporate a 9-pos pattern selector.



Chris
 
pardon me, but where did you get that nice small trafo made, I'm always looking for small tx for this specs

nicholas
 
Total Price for material, power supply, shockmount & Capsule skinning: ca. 1200.- EUR

Nicholas:
The Trafo was made by a friend's fathers company - they normally do high power trafos.
It has been wound sundays as the owed me a favour...
It is not available commercialy.
I'll try the LT1085 - Many Thanks.
Did you check Tube-Town.net for trafos? They are similar to mine, but a little bit bigger.

A lot of people asked how it sounds:
Well, sound talk is difficult. I have compared and used this mic for a while and I can say: This thingy has B A L L S !!! Hard to discribe but there is an authority in the sound this mic produces - even tested blindly against commercially sold Mics of the top class - the only thing I couldn't compare it to was an original U47.
No Sibilance, but more shine, more meat, more detail, more air, the bass simply blows you away - even my own (crappy) voice  sounds terrific.


I know this sounds enthusiastic - but please built one for yourself and do a blind test! I promise, this is money well spent.
At first I was a bit uncertain because I did not use a VF14 (Those prices are ridicoulus). Probably it would sound even better.
Other than that the critical components of this built are as close as possible... it wasn't my intention to do an historically correct clone - this one is made for useage!
For now I think the decision was right to go for an EF86 / transformer combination.
Mr. Thiersch did an excellent job on the skinning of the capsule (as always).


Many thanks to Max' for his MK7 circuit - this mic would probably not have been made without its inspiration!

Unfortunately the Flea kit is sold out now - I would love to built a second one...


Regards,

Chris
 
chefducuisine said:
Nicholas:
The Trafo was made by a friend's fathers company - they normally do high power trafos.
It has been wound sundays as the owed me a favour...
It is not available commercialy.
I'll try the LT1085 - Many Thanks.
Did you check Tube-Town.net for trafos? They are similar to mine, but a little bit bigger.

I see, the size is what I liked so much about that trafo !!!
I'm going to post my very similar atempt too !
 
great stuff and nice pics!
I think the combination of the ballsy K47 with self biasing EF86 & matching transformer is a wise choice.
Did you experiment to find the value of the coupling cap?
 
Max,


many thanks for the compliments - at least this is based on your Ideas... Many Thanks, again!!
I've experimented with the coupling cap  - 0,33uF is what I liked best.

Regards,

Chris
 
Looks great Chris!

And nice to see another fellow Ulmer ;D. If you ever fancy a beer (or three),
I'm doing sound on most Mondays at the Sauschdall, just drop by.


Volker
 

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