L251 Capsule - anyone use one? Also CK12 options in general.

[Tim Campbell]

I don't have a photo but I recently had a pair of capsule returned to me that the customer claimed they sounded a little boomy. The capsules had literally been soaked in some strong solution like acetone. All the acrylic was shattered, melted and stuck together. He said that the mics were making a little noise so he sent them to a mic tech. The mic tech returned them in this condition and said the problems were with the capsules.

 

[Bonnie1]

Hello everyone, I thought I should jump in to set the record straight on a few comments made.

Brian Fox worked for a company that built acoustic test gear for Northern Electric (Western Electric Canada) and international phone makers. In those days frequency responses of phones was specified by law. Their competitor was Bruel&Kjaer Denmark. I am certain some of the members here would find a conversion with Brian about acoustic testing extremely beneficial and enlightening.

Brian began studying old tube microphones to find out for himself, what made them special and to understand why they are “magic". Brian made a website and shared his research for free. He also made a few custom tube microphones for various people, including a producer at Cirque Du Soleil.

Brian came to the same conclusion most of us share. 75% of what makes a stellar mic is the capsule"!

Instead of researching/ developing new capsule designs, Brian decided to retire so he could spend time with his grandchildren, write code for retro computers and play viola in a community orchestra.

A few other corrections.
-"custom tuned CK12 from Tim Cambell" (At the time (2009-2010) Brian ordered stock CT12 from Mr. Campbell).
The CT12 has gone through a couple refinements since Mr. Campbell initial release. I personally have not had the opportunity to hear the latest version of the CT12, however I believe Mr. Campbell produces an excellent version, and at an excellent price!

-"Brian Fox makes money from the RK12" (Brian has not sold a microphone since 2017)

-Accelerator, it is very possible you are a customer, here is some feedback from our side.
-Brian Fox's review of the CT12 is nothing other than positive!
-In a different thread you stated Oliver Archut made a mistake regarding B+ voltage on the Blackspade UM17 microphone line. This is not accurate!
The UM17 was already a completed design and mature product that won a TEC award. Oliver originally developed the circuit in 1997 and used it in modified Chinese microphones. Oliver licensed the design to T-Funk USA were it became the model AK47. In 2009 Oliver cut any business dealings with T-Funk USA, and shortly after licensed the design to Blackspade. Post Oliver's death, all AK47's, UM17's we have encountered, B+ is 120vdc +/- 5%.

In case anyone is interested, an early version of the UM17 circuit and a couple other of Oliver’s circuit designs used to modify Chinese mic’s were released around 2007 as bulldog mic mods, the web pages are still online as of a few months ago.

Groupdiy can be great community for knowledge and ideas. We all know that people in the audio gear world love telling stories. When a discussion involves a particular person or business. I believe it’s important for the audio community members to stick to information they have first hand/ accurate knowledge of, anything else I view as a disservice to the Audio community.

-Dennis Maximova
Atelier Magnetics & Tab-Funkenwerk

 

[kingkorg]

A few other corrections.
-"custom tuned CK12 from Tim Cambell" (At the time (2009-2010) Brian ordered stock CT12 from Mr. Campbell).
The CT12 has gone through a couple refinements since Mr. Campbell initial release. I personally have not had the opportunity to hear the latest version of the CT12, however I believe Mr. Campbell produces an excellent version, and at an excellent price!

Thank you for chiming in, and please understand i have nothing against Brian!

Your statement is, however, not correct according to Brians own words.

"We have been working with Tim Campbell to have him tune his capsules to our requirements. We want to emulate as closely as possible the response curves published by AKG originally for the c12 microphone. A critical spec for us is to have a nominal lift of 5dB in the high end and only 1dB mid-range dip.
CT12 cardiod response showing high end lift and 1dB mid range dip
You can see in this new graph (Feb 2013) that Tim has done an excellent job with tuning the capsules for us. This falls right up the centre of the spec response from AKG many years ago"

SOURCE:

https://www.foxaudioresearch.ca/CT12.htm

 

[kingkorg]

@Bonnie1 in his analysis Brian is focused on cardioid operation of the microphone, i am pointing to multi pattern forming, and off-axis performance of the CK12.

To be clear, Brian never stated his budget friendly option with less expensive edge terminated capsule had CK12 performance.

 

[Bonnie1]

Thank you for chiming in, and please understand i have nothing against Brian!

Your statement is, however, not correct according to Brians own words.

"We have been working with Tim Campbell to have him tune his capsules to our requirements. We want to emulate as closely as possible the response curves published by AKG originally for the c12 microphone. A critical spec for us is to have a nominal lift of 5dB in the high end and only 1dB mid-range dip.
CT12 cardiod response showing high end lift and 1dB mid range dip
You can see in this new graph (Feb 2013) that Tim has done an excellent job with tuning the capsules for us. This falls right up the centre of the spec response from AKG many years ago"

SOURCE:

https://www.foxaudioresearch.ca/CT12.htm

Thank you for chiming in, and please understand i have nothing against Brian!

Your statement is, however, not correct according to Brians own words.

"We have been working with Tim Campbell to have him tune his capsules to our requirements. We want to emulate as closely as possible the response curves published by AKG originally for the c12 microphone. A critical spec for us is to have a nominal lift of 5dB in the high end and only 1dB mid-range dip.
CT12 cardiod response showing high end lift and 1dB mid range dip
You can see in this new graph (Feb 2013) that Tim has done an excellent job with tuning the capsules for us. This falls right up the centre of the spec response from AKG many years ago"

SOURCE:

https://www.foxaudioresearch.ca/CT12.htm

Yes, I see that on Brian site. I spoke with Brian earlier and informed me he did not order a custom capsule from Tim, he received a stock CT12.

 

[kingkorg]

Also important correction to Brian's statement here:

"Here is an actual response of a 12+ microphone, in cardiod, with an RK12 capsule. The 180 degree (backside) rejection is 1 dB better than the original c12 specification. (>13 dB down @ 1KHZ)"

Source:
https://www.foxaudioresearch.ca/CT12.htm

This is not true. C12, and thereby CK12 has 20+db rejection at 180° @1K.

Atached original C12 spec sheet.
FR and PR graphs show 25db rejection.

 

[Accelerator]

@Tim Campbell​

Tim, no-one is here to “criticizes” your CT-12 capsule as a “bad” product and it is very logical to every-one out there that at all these years and years you will had and you will have to improve your CT-12 capsule as much as you can, otherwise you wouldn’t have the ability to stay in this “dog eat dog” business, neither to became the very famous and successful producer of your CT-12 capsule, one of the very famous and successful producer of the CK-12 capsule in the whole world.

I appreciate very much that If people have had mechanical problems you have repaired or replaced them at no cost or for the cost of shipping if they caused the damage themselves.

And that there are many members here who can attest to this.

I also appreciate very much that when people have requested that you make a capsule brighter or darker you have gladly done so at your own cost, but here is the “catch” that there are not product lines like:

Here is Tim Campbell CT-12 ‘50’s Flat-Shallow Dish Capsule with this FR, these are the characteristics, this is the datasheet… Add To Carte

Here is Tim Campbell CT-12 ‘60’s Deep Dish with this FR, these are the characteristics, this is the datasheet… Add To Carte

Any (more) info(s) about your CT-12 capsule except its photo it is in the “veil” of “mystery and focus pocus magic” and this is a little bit “problematic” for ortho-logistic people like me who likes to see the datas, to search the datas, to purchase something by the datas…

I had purchased my Moog Minimoog Voyager Select Series Analog Synth, my Radikal Techologies Accelerator Digital Synth, (yes that one that you see in my profile photo), my Kawai MP11 SE Stage Piano, my whole studio gear that cost me much-much more that the 450 Euros which is the cost of your CT-12 capsule, so money are not an object for me and I’m not venting my frustration "because I cannot purchase your capsule"…

But if All this public handwringing isn't changing anything to you for supporting more & more this DIY Community by make available for everyone to be able to purchase your CT-12 capsule, then there isn’t a reason for you to answer back to us or for us to answer back to you about a product that is Un-available or it will be available in very limited quantities…

As you can see by the very first post, almost 2 years ago, neither MBHO - Haun, Telefunken, Heiserman etc. sell their capsules and this condition hasn’t change all over these 2 years, so the most logical thing is that this DIY Community will be start making more Neumann-ique microphones, as M-7 and K-49 capsules are more available by European and American manufactures, in more reasonable prices and no limited quantities…

 

[Accelerator]

Hi @Bonnie1 and greetings from Greece.

I’m not a customer of yours, as the shipping fee, the (high) customs and the 24% VAT will be very “high” to purchased something direct from your store, but I keep informing myself from your site and of course I study the technical infos of your products…

So, «Verba volant, scripta manent» here as you & everybody can see it is the Atelier Magnetics & Tab-Funkenwerk Schematic of:

Oliver Archut U47 Alternative Tube schematic with Remote Polarity Switch on Power Supply Unit

Which have +105 volts Vb for the Plate Voltage & the Polar Pattern …

This is the SOS review about the Blackspade UM17R

https://www.soundonsound.com/reviews/blackspade-um17r

In which SOS review had been wrote:

“However, it mutes completely for a few seconds when changing to the omni mode, and while that's not an issue if you expect it, it worried the heck out of me the first time I came across it!”

Here it is the U47a Premium Kit $1290

https://www.tab-funkenwerk.org/product/u47pk-u47a-premium-kit/

with the (new) 120 Volts P.S.U.

And here is the U-47a – Assembly Guide…

https://www.tab-funkenwerk.org/ami-parts/mic-kits/u47a-kits-parts/u47a-assembly-guide/

Correct me if I was somehow wrong to something that I wrote and I will sincerely apologies about it…

 

[rock soderstrom]

I'm always amazed at what kind of ************ and self-promoters are attracted to the microphone area here on groupdiy. Some guys who define themselves primarily through their steep theses and personal attacks. In essence, it's always about how supposedly great they are. Really strange but very noticeable. The only good thing about it is that most self-declared gurus disappear after a certain time just as quickly as they appeared. This is also the big difference to people who have been supporting the DIY community with knowledge and passion for many years. I look in your direction TC and KK. Thank you for that!

 

[Tim Campbell]

Here is Haun's listing for their capsule. It can be ordered through them every day https://www.mbho.de/pdf/ka1000n_ka1100k.pdf but it must be purchase in the headbasket as that is their product or from 3rd parties like Digital Audio Service https://digitalaudioservice.com/MBHO-KA-1100-K/MBHOKA1100K .

Every time someone addresses a post to me by name or mentions my product I answer it. I see nothing odd in that. Don't write directly to me by name or misrepresent my product I won't respond unless I am just contributing like any one else. I have never promoted or sold my capsules here. Please search my posts.

I am a member here and except for addressing posts about me I have actually been contributing to these threads. Earlier I got dragged into this by simply responding to why a capsule costs so much and here I actually contributed posts comparing the Lawson capsule to my own.

 

[Sidebstudio]

Nothing sounds good in that clip!! Were you there since you claim you have heard them? Oh no you weren't there and don't know any more about this video than the rest of us. Do you have any idea of the build of the mics they are testing? No.

Even the commentators couldn't agree on anything.

I think you will find almost unanimous agreement on this forum that sound clips are almost unusable for critical assessment. You can literally find a clip of any product sounding bad if that is your only goal.

I feel called into question since you commented on a video I made in 2017 and published in 2018.

Apart the introduction recorded with a camera microphone the rest of the video is made comparing the 3 mics with at least a professional setup but not stellar.
To compare something I don't feel "right" using our DAD converters or Lavry and NEVE or any other stellar converters or fancy preamp/cables we have in studio.
Your capsule was tested in the same C12 original circuit using 6072 Electro Harmonix Tube, Cinemag transformer.
The only thing that changes between mics are capsule.

I admit I used in years a total of 6 capsules before Mr. Campbell stopped selling on his website and all of them are from 2016 to 2018.
He wrote many times he changed his reference capsule for something less "airy" of the ones I tested.
I don't know if the 6 I had are from the "airy" model or not.
I have to say that as the comments on that particular video and other comments divided people into lovers and haters of this type of sound.
I have to admit that owners were always happy about the sound, especially for vocals applications in which vocals sits well in the mix without having to equalize and add air or presence.
But quality of Mr. Campbell capsule is indisputable.
They are transducer so as all transducer is a representation of the sonic "reality", they are not the reality. From an audio engineer point of view you can disagree and find that another type of capsule (the chinese one used was a k67 edge terminated) suits well your needs.
Someone's preference is not a quality judgement.

In any case, I don't understand the need to want to publicly pillory someone's work that at the moment is not available to common people.
After Mr. Campbell stopped selling his capsules we searched other suppliers without the need to diss his work.

 

[Tim Campbell]

So very sorry Sidebstudio. I have removed my comments about your video.

 

[TLRT]

Hi @OneRoomStudio and greetings from Greece.

As I know the BSA Microphones

https://bsa-microphones.ch/rs2

Use the Haun / MBHO ka1000n “CK12 capsule” for their microphones, but I don’t know if they have any will to support the DIY market with the Haun / MBHO ka1000n “CK12 capsule(s)”, although they are open about it (as they said…) for their metal-works…

So give them (BSA Microphones) a call to see what will happen about the MBHO ka1000n “CK12 capsule(s)” and keep in your mind that the Haun / MBHO ka1000n “CK12 capsule(s)” they are very expensive ones, with prices over plus+++ 450 Euros and actually they are not a “close take” to AKG CK12 capsule(s), but rather they sound neutral, smooth and a little bit “dark”, something more like a ‘50’s AKG CK-12 “Flat-Shallow Dish (50’s AKG C12, AKG-Siemens SM-203, AKG C-414-EB) over the ‘60’s AKG Deep Dish CK-12 (AKG-Telefunken ELA-M 250, 251E, AKG C-24)…

https://bsa-microphones.ch/contact-form

I also have some MBHO capsules left if you are really looking one I can help.

 

[Accelerator]

Hi @TLRT

Tag @OneRoomStudio for your offer of these MBHO / Haun capsules that you have, as he is the person who is in the “rush” & “hurry up” condition to find out a CK-12 capsule for his microphone..

But in any way I would like to thank you for your offer, even if I’m not the person who is in this “hurry up” condition…

 

[Migs 31]

Thank you to the Moderators for not locking this CK12 thread (yet).

As happened in other related threads.
Don’t know why so much angst when it comes to mic capsules/mics, specially the CK12 on this forum.
Good DIY folks.
M

 

[OneRoomStudio]

Hi @TLRT

Tag @OneRoomStudio for your offer of these MBHO / Haun capsules that you have, as he is the person who is in the “rush” & “hurry up” condition to find out a CK-12 capsule for his microphone..

But in any way I would like to thank you for your offer, even if I’m not the person who is in this “hurry up” condition…

Almost a year ago (Sept ‘23) I asked if they were available to purchase. I don’t know if that qualifies as being in a ‘“rush” & “hurry up” condition.’ Haha.

Unfortunately I’m not currently looking to buy CK12 capsules - other priorities came come up. Thanks for thinking of me though!

 

[kingkorg]

I feel called into question since you commented on a video I made in 2017 and published in 2018.

Apart the introduction recorded with a camera microphone the rest of the video is made comparing the 3 mics with at least a professional setup but not stellar.
To compare something I don't feel "right" using our DAD converters or Lavry and NEVE or any other stellar converters or fancy preamp/cables we have in studio.
Your capsule was tested in the same C12 original circuit using 6072 Electro Harmonix Tube, Cinemag transformer.
The only thing that changes between mics are capsule.

I admit I used in years a total of 6 capsules before Mr. Campbell stopped selling on his website and all of them are from 2016 to 2018.
He wrote many times he changed his reference capsule for something less "airy" of the ones I tested.
I don't know if the 6 I had are from the "airy" model or not.
I have to say that as the comments on that particular video and other comments divided people into lovers and haters of this type of sound.
I have to admit that owners were always happy about the sound, especially for vocals applications in which vocals sits well in the mix without having to equalize and add air or presence.
But quality of Mr. Campbell capsule is indisputable.
They are transducer so as all transducer is a representation of the sonic "reality", they are not the reality. From an audio engineer point of view you can disagree and find that another type of capsule (the chinese one used was a k67 edge terminated) suits well your needs.
Someone's preference is not a quality judgement.

In any case, I don't understand the need to want to publicly pillory someone's work that at the moment is not available to common people.
After Mr. Campbell stopped selling his capsules we searched other suppliers without the need to diss his work.

There's a phobia of bright sounding mics. Not every bright is the same kind of bright. I have one of the earlier (2017) brighter sounding CT12 from @Tim Campbell . I wouldn't change it for anything.