Official C12 Clone - Build and Support Thread

[Haberdasher]

Yes socket included.

Can't speak to zero ohm size, but you can even use a wire jumper, which is what I did since I biffed the smd part.

Thanks, PM.  I figured the socket would be in the pack, but I couldn't tell from looking at the pictures.

Right, I know a jumper could be tack soldered onto the pads, but resistors are cheap and I'm ordering from mouser anyway.

 

[Matador]

It's a 1206 sized 0-ohm resistor layout.

 

[mellsonic]

Hello Everybody
started building my c12
And encountered an issue
I have the latest version of the PCB and I believe in this Build thread is an older version of the [/img]instruction

My problem is that I do not know how  I need to connect pin 2 and pin 7
The instructions I have are incomplete

I am attaching a pic of the board to make it more clear/Users/mariomelle/Desktop/IMG_0716.jpg

Any suggestions as to how these two leads (pins 2 and 7) need to travel would be great.

Thank you very much for your advise

 

[Khron]

Google is your friend

1) http://danalexanderaudio.com/Micpics/AKG/c12.jpg
2) https://frank.pocnet.net/sheets/049/6/6072.pdf

 

[mellsonic]

Hello Khron
this is not the answer to my question ,that sounds for me like blablabla..
if you can tell me where i have to connect the pin 2 &7 in this specific build its ok otherwise i don't understand why you answer with this links i am a newbie.
best

 

[Khron]

I was going for the "give a man a fish" vs. "teach a man to fish" sort of thing there There's only so much you can learn by following a ready-made recipe, i think...

PS: Have you even bothered looking at the FIRST post in this thread? How much more information do you (or could you) need? ;D

Hint: it's the link called "C12 Schematic Bundle - Version 3"...

 

[mellsonic]

Hello Khron
i am not a Electronic guy and the only thing that i want to now is where i have to solder the connection.i can't read the schematic.
so anyway if there is anybody who can help me ,it will be nice.

 

[Khron]

Unless my eyes deceive me, all the tube's pins are numbered and clearly marked on the schematic, aren't they?

I see all the component names and values are also clearly marked on the circuit boards.

If you had even bothered to do even a bit of "digging" on your own, you could've found things like this (in this exact thread):
1) http://groupdiy.com/index.php?topic=51377.msg760099#msg760099
2) http://groupdiy.com/index.php?topic=51377.msg760382#msg760382
3) http://groupdiy.com/index.php?topic=51377.msg766022#msg766022 <- apparently others share my perspective as well...

 

[mellsonic]

Thank You Khron !!!!i got it.

 

[Khron]

I don't have anything against newbies, we've all been there The problem i have is with the unwillingness to even do some research, that's all

 

[rockinrob86]

Hello Khron
i am not a Electronic guy and the only thing that i want to now is where i have to solder the connection.i can't read the schematic.
so anyway if there is anybody who can help me ,it will be nice.

You really should spend some time looking at the schematic.  It will only help you, and you will be very proud of yourself when you figure it out! It also opens up a whole world of DIY - and this schematic is about as basic as they come.  Trace it out with a multimeter set on continuity

I'll even help a bit:  P5 in the top left corner means pin 5 of the output jack.  Then going counter clockwise, you'll see pins 4,6,3,8  and 1,2,3.  1,2 and 3 are connected to the transformer, which has the wires numbered. 

You'll be able to build other things without instructions and also steal things from circuits.  For instance I have converted ampex tube preamps I've winged and put together by stealing bits and pieces from other schematics, put together quick fuzz pedals, reamps, di's, on and on and on.  Reading schematics is a crucial diy skill!

 

[Khron]

That's a bit of "a blessing and a curse", when it comes to ready-made electronic kits

On one hand, yes, it's great to not have to scavenge & order & dig for all the components. On the other hand, if you just "follow the recipe", and connect the parts, and it all just works, you won't have learned much (if anything). So you'll have no idea why or how it all works.

If it happens to not work, you're stuck That's quite definitely why, with no hint of malice, Dave (from EEVblog), whenever adressing beginners, hopes that their first projects DON'T work That's because that'll require troubleshooting, and that's where learning both comes from, and is needed in

rockinrob86 i'm totally with you on that approach! ;D Much (if not all) of my analog designs in the past were bits & pieces from various circuits, used as building blocks Active filters, balanced line receivers & drivers, etc. Rod Elliott's got a pretty great site, rich both in simple but useful projects, and plenty of informative articles, starting from the very basics up some really funky concepts.

 

[Matador]

My problem is that I do not know how  I need to connect pin 2 and pin 7
The instructions I have are incomplete

Please re-check Chungers build pics in the first 20 or so pages.  Pin 2 and 7 are the two grids on each side of the dual-triode.  You will only select one half of the tube in this circuit, hence you should only connect one or the other.  Pin 2 and pin 7 are the grids of the tube.  There is also a place labeled "PLATE" and "CATH" which go to the plate and cathode of the tube, respectively.

There is a silkscreen designation labeled "GRID" that connects to either 2 or 7, depending on which side you'd like to use.

 

[mellsonic]

Hello
Thank You to everybody who is  helping me.

 

[Phrazemaster]

Hello
Thank You to everybody who is  helping me.

In your defense I must say that at first it can be quite intimidating looking at the schematics! Your electronics brothers here are right though; you need to be literate to be able to understand what you're doing!

I suggest looking up some basic electronics tutorial websites,  looking at SIMPLE schematics, learning about how to use Ohm's Law, and experimenting with some basic kits. You wouldn't expect a preschooler to start reading Moby Dick. So get some basics under your belt young man!

Kits are ok in the beginning - like imitating your parents when learning to talk. You'll get good at soldering and get exposed to the jargon. If you keep at it you will naturally move beyond them, or at least learn how to extend them and troubleshoot them.

Plus don't let these guys fool ya - they were all newbies at some point. I've done a bunch of projects and even made my own PCBs but I still consider myself a newbie.

What will help you a lot is to try to figure it out before you ask questions. We love to help but some of us get a little ticked when it seems a newcomer isn't willing to lift a finger to learn. But that's not you!

Welcome to DIY man!!

Mike

 

[Aaudio]

Hi, I have a hum problem with my C12. It sounds to me like an issue with ground, but I can´t seem to find where the problem lies. I haven´t connected the capsule yet, but I have tested to connect a cheap Studio Project C1 capsule and there is still a humming noise. When the mic is disconnected there is no noise at all, but when I connect the mic I get a really bad noise. I have checked the ground on multiple components and places on the mic, and it seems that  there is a lot that is connected to ground, even the mic body. Here is a link to what it sounds like when the mic is connected and I turn on the power supply for a few seconds and then turn it off. 

https://www.dropbox.com/sh/mfrhwbvn8ijyt78/AADBODke8SMeFHaB1dmJEyyMa?dl=0

Does anyone know what could possibly be the issue here?

 

[rockinrob86]

did you put the mic body on, so the entire mic is fully assembled?

Many of them hum when opened up

 

[Aaudio]

did you put the mic body on, so the entire mic is fully assembled?

Many of them hum when opened up

I did not have the mic body on when I did the test, but I will try definitly that. Thank you.

 

[Hotsen]

Hi guys,
I got some trouble:
In the final step, (with the mic plugged) I already got a 6.30V heater, but I cannot raise down B+ less than 150V (min trim) and bias less than +2,3V.
All the steps where good before this final one...

I got an electro harmonix 6072a/12ay7 tube
An ami T14 transformator
An Rk12 capsule
The v1.1a revision
And a 1uf c12 cap in the mic

I am from france, so my power supply is configured on 230v!
So did I need to got the same values than u?

Best
Jeremy

 

[chunger]

Hi guys,
I got some trouble:
In the final step, (with the mic plugged) I already got a 6.30V heater, but I cannot raise down B+ less than 150V (min trim) and bias less than +2,3V.
All the steps where good before this final one...

I got an electro harmonix 6072a/12ay7 tube
An ami T14 transformator
An Rk12 capsule
The v1.1a revision
And a 1uf c12 cap in the mic

I am from france, so my power supply is configured on 230v!
So did I need to got the same values than u?

Best
Jeremy

If all parts of the circuit are functioning properly, increase the value of the R1, R2 resistors to drop the B+ voltage.