Official C12 Clone - Build and Support Thread

[kidvybes]

...and Frederic having been a member since 2010 must be more than aware that after belaboring the subject within the context of this thread is more than capable of starting his own thread dedicated to the very same subject...simple remedy, no?...

 

[tonycamp]

Fredrick, seriously who do you think you're talking to? Show some respect or get off of this site.
I think the Matachung C12 has proven to sound great if put together properly and with good component choices. I also think you should step up and put your money where your mouth is by showing us a sample of something you've captured that displays all the beauty and nuance of your properly designed C12 clone? After all the belittling and condescension, it's the least you SHOULD do.
I say It better be sublime! if not.......

you know what's sublime : my first name is in my pseudo and you can't spell it correctly...

duly noted and adjusted accordingly, thanx 
lets hear the clips big shot! 

 

[tonycamp]

I must say this has gotten much less friendly than it should. This is a microphone forum thread not a white market thread. I thought the whole reason for having a section of the forum devoted to microphones was to have a place to discuss microphone design and implementation not justifying build criteria based on price point.
If you look at the topics on the first page of the microphone forum half of them are simply instructional threads by manufacturers selling products here rather than members designing and building mics themselves. I've started referring to the microphone forum here as "Kits R Us".
Frederic has been a member here since 2010, much longer than many other paticipants in this thread. From a technical standpoint he is correct, the hi-z section could be better designed. In many past builds chinese bodies have had terrible resonances. The fact that these aren't seen as a larger problem by the manufacturer of this kit doesn't negate them.
Members here might keep in mind not all participants are native english speakers and sometimes nuance is lost in translation.

hey Tim, time being here, and whether the design can be improved or not is completely beside the point, it doesn't give him the right to act like an a**hat, he's trolling, and should leave this thread, i have a hard time believing you don't understand this, and showing a position in this thread isn't a wise decision for a vendor, take it from a customer who bought 4 capsules from you and is currently scratching his head? And what percentage of your CT12's in the past couple years were sold to customers building Matachung C12's?

 

[Tim Campbell]

Tony, I understand and appreciate your point. I am honestly sorry to see members treat each other with any kind of disrespect. Others here are also guilty of not being able to let sleeping dogs lie and seem to get some pleasure out of fanning the flames.
I don't want to contribute to this mayhem or highjack this thread further.

showing a position in this thread isn't a wise decision for a vendor, take it from a customer who bought 4 capsules from you and is currently scratching his head?

I hope not Tony . I'm glad for your support and kind words for my work. My comments weren't directed at anyone in particular. Perhaps I'm just an old softy and a bit nostalgic for the kinder, gentler forum of yore.

 

[granger.frederic]

Thanks at all for your support here and on my PM !

Yest it's true , microphones are one of my passions (for a long time now ...)

But, i must say that that i'm not affected by that wave of violence ! quite the contrary !

It just proves that i've put the finger where it hurts, a painful nerve i have to say!

After all that, i hope that the most intelligent ones will understand what they have to do...

As far as i'm concern, the tone is inappropriate and i'm pleased to leave this thread now .

Cheers

 

[Matador]

It just proves that i've put the finger where it hurts, a painful nerve i have to say!

No, all it really proves is that you've gotten away (again) with dropping in to a thread, posting baseless claims about a product with which you have no direct experience, while proving no direct evidence/explanation that you are right, or even why you are right.

'Respect' is not just about 'tone':  it's also about content and intent.  Perhaps it's just me, but tone aside, doing this kind of thing just damages the community here, even if done in a 'nice tone'.  If I were to drop into a thread, and tell Tim Campbell, "Wow, I hope people aren't going to be sad when their capsules stop working due to the brass alloy you used:  Tonval brass was used in AKG's original and really is the only thing that will hold up over time...", could I expect to get a pass since I used a 'nice tone', or would I be expected to justify my words?  BTW all of that was completely made up, but it sure sounded good, didn't it?  Would we expect Tim to have to deconstruct original capsules, perform metallurgical analysis on his parts versus an original, and then show accelerated aging studies?  Just to disprove a negative?

As Chunger has said, we've been through 4 revisions on this project over the past few years, and 90% of the changes were directly from people direct experiences with either a) the build process itself, or b) the performance measured in real situations.  I've had countless people PM me with stuff like "Hey, I didn't want to cause trouble in case I'm wrong, but here is what I observed...", to which I answered "You totally should put that in the thread, because I bet others are wondering the same thing, or might experience this and wonder what caused it."  I don't even expect people to do this as a habit, but it's always nice to see people go an extra step here and that's what makes it a great place. 

I've generally gone out of my way to contribute in other's projects if I have something helpful to offer, or have experience that explains why something is the way that it is.  I wrote a JFET source resistance calculator for Poctop's U87 project, and I've never seen a single dime from that project.  I've gone to great lengths explaining tube biasing to many here.  So you don't get a pass dismissing what I say with quotes about "protecting business interests".  If you think I'm wrong, then prove it to me.

There's nothing wrong with asking questions or debating theories, but it has to be exactly that:  a question or a theory.  I find it hard to believe that you think it's a personal vendetta about your opinion, when you started off the entire process by morphing your opinion into a fact about someone else's product.  And this thread is not the first time.

I'll end with this:  next time, try this out for size: "Hey, I notice that the high impedance nodes are on the PCB rather than floating: was that a deliberate design decision?  Did you notice any mechanical issues during prototype stages?  Hey, did you change that material because you were concerned about moisture problems?"  That would have initiated a dialog, rather than just asserting something is true, and that others must be in the wrong for questioning it, and that any conceivable response can be immediately dismissed in the interest of 'protecting business interests".

 

[Tim Campbell]

If I were to drop into a thread, and tell Tim Campbell, "Wow, I hope people aren't going to be sad when their capsules stop working due to the brass alloy you used:  Tonval brass was used in AKG's original and really is the only thing that will hold up over time...", could I expect to get a pass since I used a 'nice tone', or would I be expected to justify my words?  BTW all of that was completely made up, but it sure sounded good, didn't it?  Would we expect Tim to have to deconstruct original capsules, perform metallurgical analysis on his parts versus an original, and then show accelerated aging studies?  Just to disprove a negative?

Matador, how did you know this is exactly what I've done. I thought I'd kept it from everyone but Jakob. Perhaps he's a snitch?
I've removed my post to not contribute to this ongoing struggle.

 

[granger.frederic]

i swore myself to not return here but ....i'm perhaps masochistic ...  ???

An example: i've bought (or made buy) several Tim's capsule  (or reskin)  very early (2010) , before all the threads here...

i can attest that the aging of this capsule is still today , absolutely 100% perfect, and it still sounds gorgeous.

i often check the frequency responses and it's perfectly stable, if properly used and polarized.

however, a cantilever mounted tube (like in the Matador PCB kits), non damped, has (amongst other bad things listed above) 100% chance to become microphonic with time, if it's used in front of loud sources like a guitar amp, bass amp, kick drum , etc.....due to the generated vibrations

That's why all the well built amps,preamps, and especially mics with their particular Ultra HiZ sections ,  have some tube dampening systems.

Matador, you don't respect my opinion...maybe i've made an awful choice of words (i do my best), but imagine yourself if you were in a French forum ...!

i think you'd better change your attitude, it could really affect your business here, not me !

As you've rightly observed, i'm nothing...

Stop that , think about all this,  and your work .

You cannot bury our heads in the sand and deny the facts, and please,  understand that criticism is often productive !

 

[Matador]

however, a cantilever mounted tube (like in the Matador PCB kit), non damped, has (amongst other bad things listed above) 100% chance to become microphonic with time, if it's used in front of loud sources like a guitar amp, bass amp, kick drum , etc.....due to the generated vibrations

That's why all the well built amps,preamps, and especially mics with their particular Ultra HiZ sections ,  have some tube dampening systems.

Well, at least a stake is finally in the ground.  Now now the argument is tube dampening?  What exactly does this have to do with 'High Z'?

In this design, nothing surrounding the tube would qualify as 'High Z' with the exception of a single grid node.  And it doesn't make it's way from the main PCB to the tube in any manner except a single wire:  this has been true with all design revisions.  What exactly is your envisioned '100% failure in time' mode?  Wire fatigue?  If that were true, every tube mike made in history would suffer the same problem.

There are many sources of mechanical -> sound coupling that can happen in a condenser microphone, and even ones that aren't tube based:  every mike I've had on my bench over the years exhibits this to varying degrees.  Vibration can couple to the capsule membranes...the internal tube elements can be highly microphonic (as many can attest when trying to find low noise NOS tubes).  Everything resonates at a characteristic frequency related to it's mass and it's shape.  No amount of circuit design will change this basic physics.

If the entire argument is boiling down to 'I don't like Chinese microphone bodies then that's fine:  I'm not going to debate peoples opinions on that.

 

[granger.frederic]

the tube is hardly mounted on the PCB, which is firmly in contact with the body , thus you can't avoid vibrations transmissions to the tube AND the Hiz section....
That's a very commun issue in low cost and bad sounding mics, not only chinese.

in fact the original Apex 460 dampening system (rubber mount for the tube socket, and the spring/rubber tube absorber) is not that bad...
however i find that the Hiz section is not optimal ...

Telefunken's techs, in the AR51, use the same Apex inside metalwork , except that they've reworked the body (double thickness/special coating) .I guess to reduce the vibrations transmission to the HiZ...

 

[Matador]

That's a very commun issue in low cost and bad sounding mics, not only chinese.

Then how do you explain the following 'bad sounding mics'?

U67

SE Electronics Gemini

MK47

Gefell UM57

Charter Oak SA538

 

[granger.frederic]

Se gemini is not my favorite, nor the MK47  (issues noted above...) in this revision.

The U67 is the perfect example: The HiZ section is encapsulated and hermetically sealed in a special chamber made with a non resonant/high insulation material .
The components legs inside are as short as possible and are floating/point to point
Capsule mount is usually damped
Pcb/low Z section damped by reinforcement metal beams
Minimum contact between the body and the rest of the internal structure : minimum contact between the two main beams and the body
Body resonance is reduced by the two internal swinging latches
The tube is damped by a metal hoop system (and i often put a absorbing silicon ring around it)
M269 and M367 versions have special AC701 mount with a silicon ring as well

U67= state of art in mics craftsmanship with plenty of ingenious details...

the UM57 is a nice piece of metalwork with HiZ on Acrilic/point2point, complex bracketing internal structure (45° rotation) , heavy non resonant body material.Usually, the tube is damped by an absorbing material or a hoop
there's 2 revisions for LowZ section : P2P on PCB , and through hole on PCB : no difference...

Never had the chance to try  or repair a Charter Oak SA538 but the tube seems at least a bit damped by the silicon ring and the doubled rods

 

[Melodeath00]

Matador, could you please specify what has changed in the 4 revisions of this product? I believe I have the first version, and I'm curious what's different now

 

[Matador]

Matador, could you please specify what has changed in the 4 revisions of this product? I believe I have the first version, and I'm curious what's different now

Two versions were made before release to the general, so you wouldn't have seen those.  V1.3 was the previous version, and V1.4 is the new material version. 

 

[Matador]

Se gemini is not my favorite, nor the MK47  (issues noted above...) in this revision.

The U67 is the perfect example: The HiZ section is encapsulated and hermetically sealed in a special chamber made with a non resonant/high insulation material .
The components legs inside are as short as possible and are floating/point to point
Capsule mount is usually damped
Pcb/low Z section damped by reinforcement metal beams
Minimum contact between the body and the rest of the internal structure : minimum contact between the two main beams and the body
Body resonance is reduced by the two internal swinging latches
The tube is damped by a metal hoop system (and i often put a absorbing silicon ring around it)
M269 and M367 versions have a silicon ring as well
U67= state of art in mics craftsmanship

the UM57 is a nice piece of metalwork with HiZ on Acrilic/point2point, complex bracketing internal structure (45° rotation) , heavy non resonant body material.Usually, the tube is damped by an absorbing material or a hoop
there's 2 revisions for LowZ section : P2P on PCB , and through hole on PCB : no difference...

Never had the chance to try  or repair a Charter Oak SA538 but the tube seems at least a bit damped by the silicon ring and the doubled rods

So again, High Z and mechanical resonance are two different things:  I'm not sure why they are being used interchangeably and being mixed together.

U67's are not 'hermetically' sealed in the common usage, however they are in an acrylic carrier.  The length of the components doesn't play into this, as the individual components are in the carrier, which couples mechanically to the components no different than a PCB would.  The latches have nothing to do with resonance:  they are there to hold the headbasket carrier assembly to the main microphone body.  Silicon rings don't have enough mass to change any of this:  more likely it is to prevent contact with the main PCB and the tube, which might cause tube breakage due to the sharp through-hole points on the PCB.  The metal hoop, if anything, ties the tube more firmly to the microphone body, and is there to prevent the tube from shifting in the socket, which would only exacerbate the problem you are trying to describe.

High Z components were/are 'floated' for two reasons: a) to minimize the risk of contamination from the build process, and b) to utilize air as the isolation medium between the various nodes.  The circuit action here is well understood, and I've covered it multiple times in the thread.  High impedances are not a microphone thing, and these PCB principles wrt. high impedance have been worked out years ago in GHz radio receivers, high speed backplanes, and other realms.  And none of them typically 'float' anything (Google the term 'guard ring' to find the preferred solution to this problem), because you end up with reliability, serviceability, and manufacturing problems.

The soldermask material used in this design has a similar volume resistivity as air, so neither is better or worse than the other wrt. 'b' above.  So it comes down to build contamination, which is why IPA cleaning is needed.  PTFE is also a great material, but it is incredibly expensive and very difficult to machine precisely, which puts it squarely out of DIY land.  If I wanted to charge $4k per microphone I might use it after all.

Again, most of your complaints seem to be centered around your dislike of the body, which again is fine.

 

[kidvybes]

...comment dit-on "belaboring"?...  ???

 

[Melodeath00]

Matador, could you please specify what has changed in the 4 revisions of this product? I believe I have the first version, and I'm curious what's different now

Two versions were made before release to the general, so you wouldn't have seen those.  V1.3 was the previous version, and V1.4 is the new material version.

Ah, that makes sense. Thanks!

By the way, tonight I tested out my C12 as an under snare mic, and discovered it's easily the best mic I've ever used for that position. It has the air that you're looking for from that spot, but none of the harsh cheapness that dynamics I've tried exhibit. I just covered it up with the cylindrical pop shield that came with the HT-11A kit to protect the capsule from any dust that might fly around from the hits, since it's such an open headbasket. Any reason to not use the C12 on a snare? I wouldn't use it on top, but the bottom snare seems like the safest position for a mic on a kit.

 

[Tim Campbell]

Melodeath00,
You don't mention what capsule you are using. A CK12 capsule isn't center terminated and when exposed to high pressure  the membrane hits the backplate.  After repairing hundreds of CK12 capsules that have been used to mic guitar cabinets or close mic drums I'd say that using a CK12 capsule on loud sources almost guarantees destroying the membranes over time.
If it's a cheap chinese capsule perhaps it's worth the tradeoff. If it's my capsule please use a pop filter and move it further away.
If it's another manufacturer's please continue using it on loud source so that in the future if it fails you can replace it with mine  ;D

 

[granger.frederic]

Matador, do you have a U67 ?
The U67 has normally two hermetically and mechanically sealed HiZ chambers (unless it has been tweaked for repair)
You should have  a membrane on the top of the bottom chamber.(however not sure for the earlier copies...my M367 has one , my U87 also...)Anyway , the chamber is mechanically sealed when both parts are locked.
The top chamber is mechanically sealed and there's a absorbing material, for the capsule mount and HiZ wires, on the top.
Inside, the components legs are teflon coated and the mechanical parts (switches...) are very stable/non resonant.
Silicon or rubber silent blocks are present for mechanical decoupling (AC701 U67s version,C12,U47,All Neumann actual tube mic line, etc) or as an attempt to reduce the glass tube vibrations (silicon ring : Apex, AR51, Charter oak, and many many others...)
The metal hoop reduces the tube vibrations/accidental tube movement caused by vibrations/Hiz noises caused by movements-pins/socket
When coupled with absorbing material, its effect in vastly improved as it can indeed generate some medium/high freq resonances.
Latches are here to lock the headbasket, and it also damps the vibrations in the same time (very ingenious, the ELAM has also a quite similar system )

HiZ microphonic issues and internal resonances are intimately linked, it's understandable, and if you look carefully at all the classic mics , you will find A LOT of ingenious damping/insolation systems inside, best examples: ELAM251(very complex)...and even the Shure SM7 (very efficient/ingenious silent block)

Beside that, electric insulation is also essential, and moisture insolation as well, and all that parameters are intricately linked...

you have the same issues in a tonearm : manufacturers often use a lot of ingenious set of components like non resonant Litz wires and non resonant materials (acrylic, carbon,ptfe....) ,etc...for the cartridge , plate , tonearm, and all the parts of the HiZ sections.

Hats off to Ioaudio who has perfectly reworked his kit in the new MK-U47 revision, caring all the details...(even if i prefer another VF14 alternative but that's another story...)

I add that It's not necessary to use some very loud sources, to find some annoying resonance frequencies of a badly designed mic ...

 

[HHH]

.... and if you look carefully at all the classic mics , you will find A LOT of ingenious damping/insolation systems inside, best examples: ELAM251(very complex)...and even the Shure SM7 (very efficient/ingenious silent block)

I assume my Neumann M249 has some of these too. But then it attaches to a U shaped yoke mount that has no shock absorption at all.