CK12 Capsule Questions (for new DIY build & mod of WA251)

[SuicideSquid]

Hi all,

I've got one project on the go - a full rebuild of an Apex 460B tube microphone - and another under consideration (some modifications to a Warm Audio WA-251).

I'm looking for a quality capsule to put in the Apex mod, and also curious about the possibility of upgrading the WA-251.

I've bought capsules from Microphone Parts before and been satisfied with the quality and with Matt McGlynn's service and responsiveness to questions, so I'm certainly open to buying a micparts capsule or two again, but am curious about other options - I am willing to spend a bit more if it means getting something that is meaningfully better.

In a similar price range to the Microphone Parts capsules there's a Mic & Mod CK12 capsule, as well as a CK12-style capsule sold by Tab Funkenwerk

On the higher end, I've read through a couple of threads on C12 mics and capsules and gather that Tim Campbell makes pretty much the closest replication of the original CK12 (the "CT12"), but I also gather he's swamped and not taking orders at the moment. The Beesneez CK12 capsule is a similar price - about $400 USD.

If I'm going to stay in the $100-$200 range, I'll likely stick with Microphone Parts as I've bought from them and have been satisfied with their products, unless someone can emphatically tell me the M&M or TF capsule is significantly better.

Does anyone out there have experience with one of these mid-range C12-style capsules, and the Beesneez CK12 capsule? Is there a difference in quality significant enough to justify more than doubling the purchase price? And are there other mid-range or high-end options (topping out at $500, I'm not made of money...) that I've overlooked? I know there are a million cheap CK12-style capsules floating around but I'd like to go with something with a little more consistency and quality control.

Thanks in advance for your feedback!

 

[kingkorg]

Hi all,

I've got one project on the go - a full rebuild of an Apex 460B tube microphone - and another under consideration (some modifications to a Warm Audio WA-251).

I'm looking for a quality capsule to put in the Apex mod, and also curious about the possibility of upgrading the WA-251.

I've bought capsules from Microphone Parts before and been satisfied with the quality and with Matt McGlynn's service and responsiveness to questions, so I'm certainly open to buying a micparts capsule or two again, but am curious about other options - I am willing to spend a bit more if it means getting something that is meaningfully better.

In a similar price range to the Microphone Parts capsules there's a Mic & Mod CK12 capsule, as well as a CK12-style capsule sold by Tab Funkenwerk

On the higher end, I've read through a couple of threads on C12 mics and capsules and gather that Tim Campbell makes pretty much the closest replication of the original CK12 (the "CT12"), but I also gather he's swamped and not taking orders at the moment. The Beesneez CK12 capsule is a similar price - about $400 USD.

If I'm going to stay in the $100-$200 range, I'll likely stick with Microphone Parts as I've bought from them and have been satisfied with their products, unless someone can emphatically tell me the M&M or TF capsule is significantly better.

Does anyone out there have experience with one of these mid-range C12-style capsules, and the Beesneez CK12 capsule? Is there a difference in quality significant enough to justify more than doubling the purchase price? And are there other mid-range or high-end options (topping out at $500, I'm not made of money...) that I've overlooked? I know there are a million cheap CK12-style capsules floating around but I'd like to go with something with a little more consistency and quality control.

Thanks in advance for your feedback!

There's ton of info on these all over the forum, including the recently started ones. Use search. None of the mentioned besides Beesneez have anything to do with CK12 including the MP one. They just look similar. There's no free lunch with CK12, according to recent threads Beesneez is currently best bet, and the only one readily available. All the "budget" one's are just rebranded 30$ capsules you can find on Aliexpress. WA has already "best" version of this type quazi CK12, so no point upgrading it unless you go for the real thing.

 

[SuicideSquid]

There's ton of info on these all over the forum, including the recently started ones. Use search. None of the mentioned besides Beesneez have anything to do with CK12 including the MP one. They just look similar. There's no free lunch with CK12, according to recent threads Beesneez is currently best bet, and the only one readily available. All the "budget" one's are just rebranded 30$ capsules you can find on Aliexpress. WA has already "best" version of this type quazi CK12, so no point upgrading it unless you go for the real thing.

I did use the search, the first half-dozen results were eihter people talking about / with Tim Campbell (not relevant since his aren't available at the moment) or arguing about cheap Chinese capsules so the feedback is very much appreciated. Thank you!

 

[kingkorg]

I did use the search, the first half-dozen results were eihter people talking about / with Tim Campbell (not relevant since his aren't available at the moment) or arguing about cheap Chinese capsules so the feedback is very much appreciated. Thank you!

- Well the point is there are real CK12
https://groupdiy.com/threads/another-ck12-thread-whats-available-in-2023.85035/
- There are 30$ chinese capsules, nothing wrong with these just not CK12, and sound nothing alike.

- There are rebranded Chinese ones sold by MP, Maiku and others hiding behind various marketing plots and fake QC claims

- And high quality Chinese capsules which are really quality checked under high manufacturing standards - 3U Audio (one of which you have in the WA), 797 Audio (Slate ML-1 is good example) and Australian manufactured Røde capsules which are of the same construction.

There's been talk 3U audio should come out with their true CK12, so if you are not in hurry...

 

[SuicideSquid]

There's been talk 3U audio should come out with their true CK12, so if you are not in hurry...

I am not. I'd like to have something together when I start recording my band's next album, but that's likely six months off. I can certainly be patient and see what 3U comes out with, and/or see if I can get in Tim Campbell's queue.

 

[Whoops]

I would leave the WA-251 capsule alone, it sounds pretty good already that mic, you might spend $400 and then not even feel you like the new sound better.

As for the Apex 460B, do you really need a CK12 type capsule for this mic?
If you could use a K87 or K47 capsule in that mic, you have great options from Arienne:
https://www.arienneaudio.com/
Also 3U audio makes great capsules

 

[madbeavis]

Just ordered a Beesneez CK12 and a Raytheon triple-mica 6072 for my wm-251. Ill post later once I have time to test this.

I would also like to point out that the internals of all the Warm Audio mics are top-tier with the exception of the tubes and capsules. The capacitors, transformers, and relays are all the exact parts I would use in a custom build but for far cheaper then I could have sourced them.

 

[garp]

Hummmm the moment there is a relay the "exact parts" argument flyes away, i don't know what warm is offering as 251 clone but i am quite sure that they are wayyyy overpriced for their content.

 

[pasarski]

I bought b-stock wa-251 for a modding platform. I actually bought it because of the relays that enable the use of isolated backplate based pattern switching. I have not been successful implementing relays in the high z parts in a microphone myself so I thought if they succeeded I can pay a little for that.

It sounded ok stock, but nothing like my builds with a CT12 capsule or the Bock 251 which is probably the fanciest clone I've tried. The circuit is same as the original 251 (with couple of wrong component values). It's not overly bright mic for my surprise but grainy I would say.

Changed the stock tube for a NOS 12AY7 which made the mic too bright. The stock tube which was a JJ 12AY7 somehow compensated for the overly bright capsule. I kind or appreciate that kind of engineering - if it was intentional But yeah the new 12AY7's seem to be nothing like the originals.

Now I have a CT12 in and the mic sounds great. Changed the output cap for a 1uF (a Soviet PIO because I could just fit it in and it looks cool). The stock one was a nice axial polypropylene cap but at 3.9uF too large value for the small transformer I think. Added a resistor to PSU to drop the B+ to 120V. It was something like 140-150V. If you put a CT12 in the mic this (or replacing the zeners) is an essential step. At least CT12's made ten years ago don't like polarization voltages over 60V (I don't know if this has changed?). Also removed the 100pf plate to ground because I like air. Not sure if I can hear the difference though to be honest.

Also, changed this one resistor which should have been the 30meg grid to ground but I'm not sure if it was a resistor at all? The color codes doesn't seem to make sense. Tried to measure it paraller with a smaller resistor and compare the reading to other high value resistors, but it seems it really is not a resistor or it's a really really high value one. Anyways I did change it for a 33meg metal film one.

I have to agree it's overpriced (not the only overpriced mic on the market though) and quite odd design. Nice things combined with some weirdness in a cheap Chinese package (I like the color though). But I'm happy for what I paid and the relay switching seems to work, which was what I hoped for.

Edit: For the OP, don't by MP capsules, they are the same you can get from Ali a lot cheaper like others have said and if you change the tube for a better one be ready to have a really bright mic with any k67 type of capsule like the stock one.

 

[sodle11]

Just ordered a Beesneez CK12 and a Raytheon triple-mica 6072 for my wm-251. Ill post later once I have time to test this.

I would also like to point out that the internals of all the Warm Audio mics are top-tier with the exception of the tubes and capsules. The capacitors, transformers, and relays are all the exact parts I would use in a custom build but for far cheaper then I could have sourced them.

been recording vocals with my WA-251 and not loving the harshness, doesn't sound open like a 251 should. hoping a real CK12 style capsule fixes that. any update on your mod madbeavis?

 

[Accelerator]

@SuicideSquid & @sodle11

Before you spend your hard earnest money to buy any “fancy” and expensive “CK-12” capsule like:

The OP12(CK12 TYPE) $428.29 USD.

or

The Beesneez CK12 capsule is a similar price - about $427.78 USD.

There are a whola lotsa mods. that you can do, to improve the mediocre FR of your Warm Audio WA-251 microphone…

1.Added a resistor to PSU or find a combination with zener diodes to drop the B+ to 120V.

2.Replace the ridiculous 30ΜΩ Grid-leak Resistor with a 200MΩ Grid-leak Resistor (AKG C-12 VR, AKG-Siemens SM-203, AKG C-24, AKG Perception 820) or even with higher value like up to 1GΩ Grid-leak Resistor (AKG Solidtube) if you want a flatter down to earthquake earth 20 Hertz Frequency Response…

If you have questions about it, ask Siemens, the leading Co. of the Telefunken GmBH Trast (group of companies) why they holded a grange against Neumann, so Siemens forced the AKG to make an Anti-Neumann U-47 microphone…

3.Replace the JJ 12AY7-6072 with a JJ ECC802-12AU7 tube and in the same time you should replace the Cathode Resistor from the stock 1800Ω to 5366Ω Cathode Resistor if you use it as a single plate follower or you should replace the Cathode Resistor from the stock 1800Ω to 2175Ω Cathode Resistor if you wired the JJ ECC802-12AU7 tube “en parallèle”…

This mod. will makes a better matching with the output transformer and gives you a more AKG-Telefunken ELA-M 250 (non E) with AC701 tube “feeling”, in other words something more “Neumann-ique”…

 

[sodle11]

@SuicideSquid & @sodle11

Before you spend your hard earnest money to buy any “fancy” and expensive “CK-12” capsule like:

The OP12(CK12 TYPE) $428.29 USD.

or

The Beesneez CK12 capsule is a similar price - about $427.78 USD.

There are a whola lotsa mods. that you can do, to improve the mediocre FR of your Warm Audio WA-251 microphone…

1.Added a resistor to PSU or find a combination with zener diodes to drop the B+ to 120V.

2.Replace the ridiculous 30ΜΩ Grid-leak Resistor with a 200MΩ Grid-leak Resistor (AKG C-12 VR, AKG-Siemens SM-203, AKG C-24, AKG Perception 820) or even with higher value like up to 1GΩ Grid-leak Resistor (AKG Solidtube) if you want a flatter down to earthquake earth 20 Hertz Frequency Response…

If you have questions about it, ask Siemens, the leading Co. of the Telefunken GmBH Trast (group of companies) why they holded a grange against Neumann, so Siemens forced the AKG to make an Anti-Neumann U-47 microphone…

3.Replace the JJ 12AY7-6072 with a JJ ECC802-12AU7 tube and in the same time you should replace the Cathode Resistor from the stock 1800Ω to 5366Ω Cathode Resistor if you use it as a single plate follower or you should replace the Cathode Resistor from the stock 1800Ω to 2175Ω Cathode Resistor if you wired the JJ ECC802-12AU7 tube “en parallèle”…

This mod. will makes a better matching with the output transformer and gives you a more AKG-Telefunken ELA-M 250 (non E) with AC701 tube “feeling”, in other words something more “Neumann-ique”…

Thanks for the tips! Good place to source these parts from?

 

[Accelerator]

Thanks for the tips! Good place to source these parts from?

As I come from Greece…- I prefer the Banzai Music GmbH

for the tubes, capacitors, resistors or even the

Farnell® Ελλάδα | Διανομέας Ηλεκτρονικών

For capacitors, resistors, transformers in European market …

If you are an American take a look at the

Welcome to Farnell Global | Global Electronic Component

Or even at the all-time classic

Mouser Electronics | No Min Orders & Fast Delivery

 

[madbeavis]

Finished the mods:
- NOS 6072 "triple mica" Ratheon tube
-BeesNeez CK12 clone capsule

To install the new capsule you will need to drill a new hole in the capsule platform as the BN cradle is single scew (stock capsule cradle is 2 hole).

For the PCB I used a desoldering vacuum tool which worked great. The Warm PCB has large pads/drills which makes this easy. The tube change requires no additional mods.

The BN CK12 capsule has a completely different construction over the stock capsule. It appears to be a "brass-ring" version of the CK12 and dimensions look similar to images of this CK12 version from the web. The stock capsule was physically larger and the plates appear to be different sizes too.

Sound tests:

The new capsule has smooth low mids and is not over-hyped in the 8k range. The capsule is still "bright" but that should be expected from a CK12. The new capsule is also quieter, I remember reading somewhere that AKG changed the internal dimensions of the CK12 in the 70's to add a 3DB boost that resulted in more high-mid response and I think that is the design the warm capsule is based on.

When singing the new capsule is open and transparent when compared to the stock capsule. It seems to be "faster" and is a vast improvement in responsiveness that is totally worth the cost.

I dont have any other CK12-type mics but I did compare this to my other clones

U47 (Tab) with C3G tube and Nuemann K49 capsule:
The modded warm does well when compared to this mic even thought they are vastly different. The 47 is more aggressive and forward in the mids but the 251 does not sound cheap by comparison which was my goal with these mods.

M49 (Tab) with 6947 tube and Dachmann M7 capsule:
This mic is very smooth and rich. The 251 sounds nothing like it but that should be expected. Again the 251 did not sound like a cheap mic in this comparison either. These two mics id say were the most different even though the circuit is very similar.

Overall I spent $1250
-Used WA-251 $600
-Ratheon 6072 $150
-BN CK12 capsule $400

If you do the math that is less then the cost of a Tab kit for a already quiet mic with mods.

For those who are curious about the BeesNeez CK12 capsule:
The build quality is excellent and it sounds great. Totally worth the price, in fact I think they could probs charge more for this. There are very few CK12 manufactures out there using this design that you can buy direct from.

This was totally worth the time+money but now I want a BeesNeez Phalecity.

Hope you enjoyed my ramblings

Side Note:
The relay thing is a problem when switching polar patterns DC is briefly connected to the grid which makes some nasty noises. The make-before-break switch on the PSU could be improved to prevent some of this but it only occurs when manipulating the pattern switch. For a quite mic at this price im willing to tolerate it.

 

[sodle11]

Finished the mods:
- NOS 6072 "triple mica" Ratheon tube
-BeesNeez CK12 clone capsule

To install the new capsule you will need to drill a new hole in the capsule platform as the BN cradle is single scew (stock capsule cradle is 2 hole).

For the PCB I used a desoldering vacuum tool which worked great. The Warm PCB has large pads/drills which makes this easy. The tube change requires no additional mods.

The BN CK12 capsule has a completely different construction over the stock capsule. It appears to be a "brass-ring" version of the CK12 and dimensions look similar to images of this CK12 version from the web. The stock capsule was physically larger and the plates appear to be different sizes too.

Sound tests:

The new capsule has smooth low mids and is not over-hyped in the 8k range. The capsule is still "bright" but that should be expected from a CK12. The new capsule is also quieter, I remember reading somewhere that AKG changed the internal dimensions of the CK12 in the 70's to add a 3DB boost that resulted in more high-mid response and I think that is the design the warm capsule is based on.

When singing the new capsule is open and transparent when compared to the stock capsule. It seems to be "faster" and is a vast improvement in responsiveness that is totally worth the cost.

I dont have any other CK12-type mics but I did compare this to my other clones

U47 (Tab) with C3G tube and Nuemann K49 capsule:
The modded warm does well when compared to this mic even thought they are vastly different. The 47 is more aggressive and forward in the mids but the 251 does not sound cheap by comparison which was my goal with these mods.

M49 (Tab) with 6947 tube and Dachmann M7 capsule:
This mic is very smooth and rich. The 251 sounds nothing like it but that should be expected. Again the 251 did not sound like a cheap mic in this comparison either. These two mics id say were the most different even though the circuit is very similar.

Overall I spent $1250
-Used WA-251 $600
-Ratheon 6072 $150
-BN CK12 capsule $400

If you do the math that is less then the cost of a Tab kit for a already quiet mic with mods.

For those who are curious about the BeesNeez CK12 capsule:
The build quality is excellent and it sounds great. Totally worth the price, in fact I think they could probs charge more for this. There are very few CK12 manufactures out there using this design that you can buy direct from.

This was totally worth the time+money but now I want a BeesNeez Phalecity.

Hope you enjoyed my ramblings

Side Note:
The relay thing is a problem when switching polar patterns DC is briefly connected to the grid which makes some nasty noises. The make-before-break switch on the PSU could be improved to prevent some of this but it only occurs when manipulating the pattern switch. For a quite mic at this price im willing to tolerate it.

Great info! Thanks for your effort. I picked up my wa251 for $450 (used b stock, great deal) so may be worth it to pay for the whole signal art mod with the capsule replacement. Extra few hundred bucks may we worth my time and all the extra stuff he does to the internals. We’ll see, and thanks again for all the info!

 

[Luckyadnan]

@SuicideSquid & @sodle11

Before you spend your hard earnest money to buy any “fancy” and expensive “CK-12” capsule like:

The OP12(CK12 TYPE) $428.29 USD.

or

The Beesneez CK12 capsule is a similar price - about $427.78 USD.

There are a whola lotsa mods. that you can do, to improve the mediocre FR of your Warm Audio WA-251 microphone…

1.Added a resistor to PSU or find a combination with zener diodes to drop the B+ to 120V.

2.Replace the ridiculous 30ΜΩ Grid-leak Resistor with a 200MΩ Grid-leak Resistor (AKG C-12 VR, AKG-Siemens SM-203, AKG C-24, AKG Perception 820) or even with higher value like up to 1GΩ Grid-leak Resistor (AKG Solidtube) if you want a flatter down to earthquake earth 20 Hertz Frequency Response…

If you have questions about it, ask Siemens, the leading Co. of the Telefunken GmBH Trast (group of companies) why they holded a grange against Neumann, so Siemens forced the AKG to make an Anti-Neumann U-47 microphone…

3.Replace the JJ 12AY7-6072 with a JJ ECC802-12AU7 tube and in the same time you should replace the Cathode Resistor from the stock 1800Ω to 5366Ω Cathode Resistor if you use it as a single plate follower or you should replace the Cathode Resistor from the stock 1800Ω to 2175Ω Cathode Resistor if you wired the JJ ECC802-12AU7 tube “en parallèle”…

This mod. will makes a better matching with the output transformer and gives you a more AKG-Telefunken ELA-M 250 (non E) with AC701 tube “feeling”, in other words something more “Neumann-ique”…

hello sir can u explain what material name should i buy for this? wanna try it but i dont understand

 

[Luckyadnan]

Thanks for the tips! Good place to source these parts from?

helo sodle do u understand what part should change on this? can u explain me with picture? i really want try this

 

[Luckyadnan]

@SuicideSquid & @sodle11

Before you spend your hard earnest money to buy any “fancy” and expensive “CK-12” capsule like:

The OP12(CK12 TYPE) $428.29 USD.

or

The Beesneez CK12 capsule is a similar price - about $427.78 USD.

There are a whola lotsa mods. that you can do, to improve the mediocre FR of your Warm Audio WA-251 microphone…

1.Added a resistor to PSU or find a combination with zener diodes to drop the B+ to 120V.

2.Replace the ridiculous 30ΜΩ Grid-leak Resistor with a 200MΩ Grid-leak Resistor (AKG C-12 VR, AKG-Siemens SM-203, AKG C-24, AKG Perception 820) or even with higher value like up to 1GΩ Grid-leak Resistor (AKG Solidtube) if you want a flatter down to earthquake earth 20 Hertz Frequency Response…

If you have questions about it, ask Siemens, the leading Co. of the Telefunken GmBH Trast (group of companies) why they holded a grange against Neumann, so Siemens forced the AKG to make an Anti-Neumann U-47 microphone…

3.Replace the JJ 12AY7-6072 with a JJ ECC802-12AU7 tube and in the same time you should replace the Cathode Resistor from the stock 1800Ω to 5366Ω Cathode Resistor if you use it as a single plate follower or you should replace the Cathode Resistor from the stock 1800Ω to 2175Ω Cathode Resistor if you wired the JJ ECC802-12AU7 tube “en parallèle”…

This mod. will makes a better matching with the output transformer and gives you a more AKG-Telefunken ELA-M 250 (non E) with AC701 tube “feeling”, in other words something more “Neumann-ique”…

hello sir can u explain what material name should i buy for this? wanna try it but i dont understand

 

[Accelerator]

@Luckyadnan

hello sir can u explain what material name should i buy for this? wanna try it but i dont understand

Welcome on board and greetings from Greece!...
In these photos, it is mostly pictured out this “yellow” capacitor, which probable it is an electrolytic tantalum…

 

[Luckyadnan]

@Luckyadnan

Welcome on board and greetings from Greece!...
In these photos, it is mostly pictured out this “yellow” capacitor, which probable it is an electrolytic tantalum…

hi greeting from indonesia, ahh so i just only need to change the “yellow” electroltic capacitor? i mean the ridiculous 30ΜΩ Grid-leak Resistor is a “yellow” tantalum resistor? and just need to be replace with 200MΩ “yellow” tantalum resistor?