Official C12 Clone - Build and Support Thread

Thank you!

Question #2

Can I use this power supply for the 251?

Thank you
Geek

Yes.
The circuit changes in a 251 are on the mic side.

TillM said:

Yes.
The circuit changes in a 251 are on the mic side.

Click to expand...

Thank you TillM
I'm having a problem with wiring the tube daughter board. The newer version is marked differently. Not sure where to go with these 2 connections. Not sure if that extra turret goes on the top or bottom of the board (Plate)....are there modified instructions for the updated boards within the 127 pages of this thread? v1.4a is a bit different than v1.

Thank you
Geek

geekmacdaddy said:

Thank you!

Question #2

Can I use this power supply for the 251?

Thank you
Geek

Click to expand...

Yes!

"In our new power supply, we will need pin 4 to send our bias voltage to the microphone, so you will need to cut the ground bridge to pin 4 and solder a new wire if reusing the stock wires on the 7 pin XLR."

Got that. I have a 7pin cable from an old mic and one end has the ground bridge on pin 4. Should I remove that?

Thank you
Geek

geekmacdaddy said:

Not sure where to go with these 2 connections.

Click to expand...

Which two connections?

Hi, I recently finished my C12 build with a GE6027a and an RK12 and was enjoying it immensely. All values coming in perfectly. Sounding quiet and 3D. No complaints. Then my Tim Campbell CT12 came in, so i excitedly swapped out the capsule. Following the instructions from the original build thread, I strapped the two backplate terminals together, and wired them both to the BP terminal. I wired the front capsule to FC, rear to RC.

The mic was working great for a day of vocals, but all of a sudden today a windy hissing set in. It's now quite noisy, with intermittent hisses, and constant windy noise. When i turn the pattern knob, both of these noise elements swell and then settle. The top end on the front capsule has also become significantly diminished.

I carefully re-cleaned all the terminals where I had introduced new flux in swapping the capsule, and checked all my values which are reading perfectly. Cable and signal chain all good.

Another thing I noticed, in addition to the problem with the pattern knob switching, is the rear side of the capsule on figure 8 had significantly diminished top end from the start.

Any ideas? Did I do something wrong with my capsule installation?

Sounds like a connecting problem on the capsule.
Look at the capsule grounding connection and tighten the screw.
Be careful, cause the messing screws are sensitive.

Yes, check that all connections are snug as I mention in the manual that accompanies the capsule.
If you have further problems please conact me.

Yes, thanks guys, that did the trick. I suppose I had been too conservative on the initial tightening. Better than too zealous, I suppose. Thanks again!

Will the Aurycle body work with this kit?

JerryPbury said:

Will the Aurycle body work with this kit?

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Never tried one:  however it looks exactly the same as the Alctron body, just in raw brass.

Matador said:

Never tried one:  however it looks exactly the same as the Alctron body, just in raw brass.

Click to expand...

It gives dimensions for it on the web page, are they consistent with the Alctron body?
http://aurycle.com/aurycle-a5500-large-diaphragm-tube-condenser-diy-microphone.html

Interesting (for me) discovery today. I decided to see (if I could) what the actual differences were between the C12, The “Tube” and the CV12. There are actually more component differences between “The Tube” and the CV12 than there are between the C12 and “The Tube”.
Other than the obvious Capsule difference and the option on “The Tube” to use the other half of the 6072 to boost output the only other difference was the inclusion of a pad switch instead of C10 and R11. The power supply has been beefed up and includes the switch to change the slope on the mic. So if I am correct (debatable) the changes to “The Tube” would be to replace the capsule, remove the inner screen on the headbasket and set the pad switch to -10 dB which would put the mic even closer to a C12. What do you think?

Tried my c12 today and its stopped working?
B+ is down to 88v and when I turn off it shoots up?
Worked fine, will check cable, heater at 6.3v, bias was down?

Could it be the tube gone?

Need to test psu is ok, what load resistor do I need for B+?

Ah ok I can answer my own question, 180k load resistor, will test then check everything is chunky dory, might try another tube in it if I can find one.

have looked at a few things, and i now am able to get the mic working but only with B+ to 104v?

The psu sits at 180v unloaded.

100k resistor to adjust B+ doesnt do anything? have tried twiddling both ways?

any ideas whats going on, as its not the tube, as H+ is 6.3v, bias is -1v.

i'll check the B+ resistors as i might need to change them?

Hi friends! Does anybody know a transformer for the PSU that takes 220-240 Volts primary(Europe) and delivers 200 V and 9,5 V secondary? I thought that should be easy to find in the web but it wasn´t...
I found that one, it´s quite expensive, but i think it´s better quality than the chinese stock transformers in the cheapo-PSUs:

https://www.ebay.de/itm/TSL-40-002-Transformator-Netz-230VAC-200V-200V-9V-6-3V-0-06A-0-06A-0-4A-INDEL/223677265717?hash=item3414343735:g:6dgAAOSwD3BdiGOI

Do you guys think, the currents are enough?

Best regards from Bavaria

All sorted now, turned out to be a faulty 100k trimmer, replaced for a 250k as per the ELAM 251 PSU and changed the 91k resistors to 68k.

Hello People that are smarter than I.
I have the mic and power supply built, and it sounds silky smooth on top, and beautiful all over, but I'm getting an almost white noise from it, and need a clarification on the building of the cable. Do the 2 jacks need to be grounded to their corresponding bodies? 1 Jack? None?

Thank you
Geek

I don’t resemble the “smarter” claim, but I’m pretty sure you have the common filth issue, get some alcohol and while being super careful to avoid and not melt your polystyrene caps, clean the living heck out of the PCB, Especially where your capsule connects to the PCB, that might help, the cord grounding scheme is exactly as you’d expect, I did nothing out of the normal on mine and it’s noise free

geekmacdaddy said:

Hello People that are smarter than I.
I have the mic and power supply built, and it sounds silky smooth on top, and beautiful all over, but I'm getting an almost white noise from it, and need a clarification on the building of the cable. Do the 2 jacks need to be grounded to their corresponding bodies? 1 Jack? None?

Thank you

Geek

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