My U47 Clone

[Enchilada]

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:

 

[micaddict]

Surely everyone is sick of my build threads by now.

Yeah..........


.............but I'm addicted, so keep 'em comin' anyway. 

 

[micaddict]

Looking good to me.
Steel tube. Ef12 family, no? Do you have a "U47 ef12" schematic to share?
And where did you get the donor body?

 

[wave]

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

 

[Enchilada]

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.

 

[Enchilada]

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.

 

[gyraf]

Could you elaborate a bit on the problem - just so others don't have to repeat any mistake you've made?

Jakob E.

 

[micaddict]

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.

 

[Dylan W]

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!

 

[Enchilada]

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.

 

[MagnetoSound]

I was just never happy with the sound of it. Maybe I should have pulled the B+ down. I had it at around 150V.

This reads like an unfinished experiment to me. 

 

[Enchilada]

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.

 

[Phrazemaster]

I'm impressed nonetheless. I'm sure you can make it work eventually!  8)

 

[Enchilada]

OK, so you guys have inspired me to order an AMI T47 transformer and a Beez Neez M7 capsule. This project will live again! This time I'll try a 105V B+ and 5V heater.

I'll leave this thread for now though and post details in my mic builds thread here.

www.groupdiy.com/index.php?topic=50171.0

 

[Phrazemaster]

OK, so you guys have inspired me to order an AMI T47 transformer and a Beez Neez M7 capsule. This project will live again! This time I'll try a 105V B+ and 5V heater.

+1!

 

[micaddict]

Now we're talkin'.  8)