My U47 Clone

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Enchilada

Well-known member
Joined
Aug 24, 2011
Messages
323
Location
Australia
Surely everyone is sick of my build threads by now. I did have a thread for this in the drawing board but I thought it would be better to put photos of the actual build in this forum.

I used an RK47 capsule, a 5693 tube and a transformer I had spare that was originally from CAD Trion 6000. I'll be replacing this transformer with an OEP A262A3E I have coming in the mail which I will try my best to squash it in there. It was tough enough to fit the CAD transformer in but I might be able to do it.

Here's a vocal recording with the mic I did tonight. Although this is the same singer/song, it has more room sound than the recording of the G7 below because I have taken down some of my acoustic panels to re-cover them, Also, it was amazingly cold in the studio and Lauren wasn't anywhere near as relaxed as she was when she sang this song into my G7.
http://soundcloud.com/kris-osullivan/u47-clone-test]http://soundcloud.com/kris-osullivan/u47-clone-test
https://dl.dropbox.com/u/42472812/Lauren%20Red-47.mp3

Also, here's another recording of the same singer and the same song recorded with a Gyraf G7 using a CK12 capsule.
http://soundcloud.com/kris-osullivan/lauren-carlson-hallelujah

Here's some photos of the mic:
Mic.jpg

Capsule.jpg

PCBFront.jpg

Tube.jpg
 
Is there a self etch PCB in there?
I'm diggin the look but there seemed to be a little too much 1Khz area for me on the vocal. Transformer maybe?

Dave
 
Yep it's a steel 5693 tube. Electronically it's very similar to the EF12. I'm not very good with CAD software so I used MS Paint to draw the PCB and etched it myself. I based this mic on an EF12 U47 schematic I found.

I agree that there a fair 1-2kHz bump and the highs roll-off fairly steeply also. This recording was around 30-40cm from the mic. I did record one take where she was right up on the mic and the proximity effect helped balance the bump. I think it's either the transformer or the tube as it's quite microphonic. I'll be trying a couple of other tubes in it and a new transformer later in the week and will post the results.
 
In case anyone comes across this thread, this project was a bit of a failure. I think I was kind of trying to reinvent the wheel here. I'll be trying again soon using Oliver Archut's schematic and a different donor mic.
 
You took the words right out of my mouth, Jakob.

Yep, failures can be just as educational, if not more so.

And we won't laugh.  ;)
No, seriously. I, for one, wouldn't have come nearly as far as you anyway.
 
I can't get the soundcloud track to work for this mic (works for the G7). If you don't mind leaving it up, it might be interesting and a good resource to hear this combination vs the G7, failed experiment or no!
 
Apparently Sound Cloud think the song infringes copyright. I can't upload it as an attachment either because it's too big.

I was just never happy with the sound of it. Maybe I should have pulled the B+ down. I had it at around 150V.
 
Updated OP with a link to an MP3 in my dropbox.

I think I'm done with this project for now but who knows. I still have the tube and the PCB. My next project is a U47 style mic using the schemo from the Tab Funkenwerk site so I'll be building a 105V/6V power supply. Might give it another crack then but for now it's going to lie dormant.
 
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