Official C12 Clone - Build and Support Thread

[Greenie]

Hi. I bought the Matador pcb in 2013/14 and it has been lying around half finished. I decide to inish it and bought a Maiku capsule, I had the Archut transformer already installed. I must say I was very surprised with how not so good it sounds, boomy and bassy with very little top end. It's sounds so "bad" that I suspect it's me that has done something wrong. How do I go about finding out if there are fatal flaws in the build? I have gone through most things, a rather simple build, so any advise on this?

 

[Nen'O]

Hi. I bought the Matador pcb in 2013/14 and it has been lying around half finished. I decide to inish it and bought a Maiku capsule, I had the Archut transformer already installed. I must say I was very surprised with how not so good it sounds, boomy and bassy with very little top end. It's sounds so "bad" that I suspect it's me that has done something wrong. How do I go about finding out if there are fatal flaws in the build? I have gone through most things, a rather simple build, so any advise on this?

Hi,
I'm new to DIY mic's and I just finished my first C12 clone. Amazing mic!
From what I understand chinese made capsule, that includes Maiku, back plate top end has roll off and sounds bassy and boomy. Maybe you got it reversed at first place. Try reversing position and wiring of capsule.
As well I was about to get Miku capsule, they were clear from begin that their capsules K12 doesn't have a high-freq bump and isn't particularly airy so instead I went for AK12.

Hope it helps

 

[Greenie]

Nen'O. That helped, A new mic.

 

[johnsonic]

Just finished mine! NOS 6072a, haufe/telefunken tx, beesneez capsule. Got a hold of the mic-only PCB and couldn't wait for the power supply PCB to be back in stock, so followed the schematic & built it on perfboard. It's not pretty but it works.

It sounds awesome!

Next stop, for science, is to see how it compares to the c12 emulation in my Townsend Sphere.

 

[johnsonic]

Sciencing is done. Really bad acoustic guitar through my build and the Sphere emulation in cardioid, figure 8, and omni. About 18" away, one mic inverted and capsules directly over eachother and same distance. They don't sound too far apart, figure 8 sounds the most different to me. Sphere has sharper highs to me and needed 4db less gain. I prefer my build (but could be biased!) C12_Comparison.zip

 

[Nen'O]

Hi,
Anyone here can share some input about good tube choice for C12 clone?
I opt for new EH 6072/12AY7 tube and BV18 transformer (8:1 turns ratio) ?
What about other double triode like ECC82/12AU7 or EC81/12AT7?
As well what about rubber strap capsule holder?
Did anyone here experiment with that?

Thanks!

 

[DT_Music]

Hi all,
I'm sure this has been covered somewhere but this thread is so huge and I couldn't find it using the search function.
I just got my boards the other day and after having studied the original build walkthrough for months, now I'm having to readjust to the V1.4 updates (it would be nice if a build guide for v1.4 would be put on the first page).

Anyway I've got the a wire connected to TP1 (from c12) and a wire from "FC" going to TK1 (my silk screening also seems a bit different from other people's builds). However in the original design, a wire is connected from the back of C13 to TG1 and on my board there is no TG1. From looking at pictures of peoples builds it looks like I should connect this wire directly to pin 2 of my tube socket. Is this correct?

Edit: Another question I have is: if I want to use a 12AT7 do I have to change anything in the mic itself, or is it just a matter of using the 33K resistors in the power supply?

Thanks a lot,
Dave

 

[funkymonksf]

I finished the PSU but one of the hi volt caps has a dent in it. I went and soldered it in but I wanted to verify with you good folks if this is problematic or worse dangerous.

 

[Icantthinkofaname]

Hi,
I'm new to DIY mic's and I just finished my first C12 clone. Amazing mic!
From what I understand chinese made capsule, that includes Maiku, back plate top end has roll off and sounds bassy and boomy. Maybe you got it reversed at first place. Try reversing position and wiring of capsule.
As well I was about to get Miku capsule, they were clear from begin that their capsules K12 doesn't have a high-freq bump and isn't particularly airy so instead I went for AK12.

Hope it helps

Maiku's capsule absolutely has a high frequency bump. It's just not the 5-6 dB bump you'd see a lot on the brighter C12s and C414s (the TLII capsule which AKG based on the brighter tuned brass capsules had a big lift). The properly made CK12s can be tuned. Maiku's capsule is probably the darker 3U edge terminated one, which has a 4 dB boost in the highs.

 

[JW]

I'm wondering what the best option for a headbasket is these days? Original reports I remember reading of a 1 layer basket being ringy, but C12 is 1 layer originally correct? Is two layer better if ordering from Chunger? Maybe 'cause it's more damp, hmmmmm. . . I dunno. Anybody tried both? Was able to locate a ct12, so I want to build a really great C12. And is there some mic transformer reading somewhere to narrow down those options. . . . ?

 

[oongbac]

I finished my C12! I’ve got sub board without any TP or TK pads, so I wired directly to socket pins.

It sounds really nice, much softer than I expected!

I used RK-12 from microphone-parts for now. I tried contact Tim for CT-12, but got no reply. Someday I’ll change that capsule, it’s quite nice anyway.

 

[DT_Music]

Does anyone know if Tim Campbell is still making/selling capsules? I know everyone says to be patient, but I notice he hasn't posted here since June, and I sent my first e-mail in early August. I don't want to bother him if he's taking a break or if something is wrong.
Follow up: If Tim's not available what's the best alternative? Should I go Maiku, Advanced Audio, Peluso, Microphone-Parts? I think Beezneez and Heiserman are a bit beyond my reach.

 

[soapfoot]

Campbell is still making capsules and I had an online interaction with him a few weeks ago.

It’s just a bit tricky as an individual to get his attention these days. I’ve heard secondhand that he’s got a fairly robust OEM demand, so there’s probably less incentive to sell per-piece to the DIY community, though it does happen.

I bought a pair from him back in (I think) May, and installed them last week. They are very good indeed

 

[klem]

I'm wondering what the best option for a headbasket is these days? Original reports I remember reading of a 1 layer basket being ringy, but C12 is 1 layer originally correct? Is two layer better if ordering from Chunger? Maybe 'cause it's more damp, hmmmmm. . . I dunno. Anybody tried both? Was able to locate a ct12, so I want to build a really great C12. And is there some mic transformer reading somewhere to narrow down those options. . . . ?

I am curious as well. I've purchased a couple of headbaskets from Chunger, IIRC some were 2 layer, but I'm a long ways from the C12 in my build queue. When I do build, I'm happy to test out these, and order some more, but yeah, it'd be nice if someone could chime in who has done this already, surely others have experimented with this given the number that have built them / length of this thread.

Also, another experiment (science!) I plan to do is trying some RTV silicone towards the base, as well as some dampening material below capsule (that doesn't disintegrate). My hope is that if the silicone is an abject failure, it will be easy enough to peel off once cured. If not, thankfully C's headbaskets are affordable and lend themselves to such efforts.

As for tx, you may want to consider Moby's T14. It's got very similar dimensions to the Cinemag option, which I'm sure is a solid option as well.

HTH,

 

[cariocaman85]

My two alctron donor PSU transformers are whining (100hz and 300hz) so I plan to replace them with custom toroidals, small enough to fit in the donor PSU cases (so max 6.5x5.5cm).
They will be 230v primary, 200v and 9.5v secondary. Do you know the Va I should go for these 2 secondaries? I was thinking 200v/0.1a and 9.5v/1a, but that might be too big for the case.
What would you recommend? Does anyone know the original donor power transformer specs?
Thanks

 

[cariocaman85]

My two alctron donor PSU transformers are whining (100hz and 300hz) so I plan to replace them with custom toroidals, small enough to fit in the donor PSU cases (so max 6.5x5.5cm).
They will be 230v primary, 200v and 9.5v secondary. Do you know the Va I should go for these 2 secondaries? I was thinking 200v/0.1a and 9.5v/1a, but that might be too big for the case.
What would you recommend? Does anyone know the original donor power transformer specs?
Thanks

Hello,
Do you think this power transformer would work? Thanks a lot

 

[Matador]

Do you think this power transformer would work?

What transformer?

The specs are pretty low: 200VAC@25mA (~5VA), and 9.5VAC@500mA (or ~5VA).

 

[cariocaman85]

What transformer?

The specs are pretty low: 200VAC@25mA (~5VA), and 9.5VAC@500mA (or ~5VA).

Thank you!

So 200vac100mA / 9.5vac1A is already overkill.

It will be a custom toroidal, hopefully small enough to fit in the donor case as replacement for the stock power transformer, as I do get a mechanic humming from 2 of them.

 

[cariocaman85]

What transformer?

The specs are pretty low: 200VAC@25mA (~5VA), and 9.5VAC@500mA (or ~5VA).

Even a 200vac0.05A / 9.5Vac/1A would be overrated X2, right?

Thanks

 

[cfanzalone]

I purchased a Mic Parts VSP1 kit to relace the Guts of an Alctron PSU...It's not too much $$ and made a night and day difference in the sound quality. No regrets at all!!