Made in the USA HK67 HK87 HK47 style capsules..AND NOW HK12 !!!!

They are really close!! I may try and tweak a little more low end in and leave the high end as it is. I do want to do another test against another clone with Tims in it, but maybe this is a good enough test to move forward!!

I just used CurveEQ to try to measure the frequency differences, and Voxengo is not really seeing any. 

Eric,
Sorry it took for ever for me to post this...

the 47 and 87 capsules sound just amazing! i cant believe how "pro" my acoustic instrument tracks are sounding. with all the capsule options out there i am very confident in my choice.

Thanks again!
Chris 

I don't really understand the reference to my capsule in this thread.

Melodeth,

I think your right!! I hadnt really listened sense the session and had assumed that the files were different. I think that the engineer may have mixed them down incorrectly...

Tim,

The refrence to your capsule is simpley this, I have a engineer friend that has a C12 Matadore Chunger clone with one of your capsules in it. He loves and it says its sound great. I am going to do a another recording test and compare, thats it.

Eric

Eric, I still don't get why my capsule should be mentioned in this thread. This is a white market thread where you are selling a capsule. That capsule should sound like an AKG CK12. You've done tests comparing it to that capsule and posted them here (or meant to)

MBHO, Josephson, Telefunken, Korby, Beesneez, Lawson, Beyerdynamic and probably some others I don't know of manufacture this capsule and will gladly sell capsules to anyone here wanting a CK12. I've seen none of them mentioned in this thread or mention of comparing your capsule to them.

Tim,

Please don't take this any other way than that you make a great capsule that I have access to. If I had another clone with a chambered capsule regardless of the manufacturer I would be doing the same side by side comparison. And trust me its not in an effort to say one sounds better or not but to hopefully go to market with a capsule that sounds good! I publicly apologize if this upsets you somehow, but that is not my intention. Moving forward please contact me directly I would prefer this thread to stay about my capsules and my development of them.
Eric

Hey everyone, I fixed the clips of the C12 vs my clone proto capsule. The c12 vocal should be correct length as well now!

Thanks Eric. Why is the vocal file for the C12 so much bigger? Takes some six or seven minutes to download.

I did listen to the acoustic guitar files. The clone/HK12 is a lot brighter there. Could it be it was closer to the headstock (further from the body) than the C12?

Albeit bright and perhaps (!) too much so, the clone does sound fresh, open and alive. The original seems somewhat tired in comparison. It doesn't strike me as a "typical C12", if there is such a thing.
Only one sample and all very preliminary, mind.

It's very interesting comparison! I truly think both sound fantastic but I would agree the c12 sounds a bit tired although very smooth. The low end is very nice though and I have some improvements I can do in that front. I may even take the brightness down a notch as well. Any other comments are greatly appreciated!!

Eric

Hi all!!

Little update regarding the ck12 style capsules. I started the machining process and I am also having a coating run so I have 100% coated Mylar. It will be a month or so before they will be available but things are moving forward.
Thanks

Hi Eric,

I am new on the forum, actually signed in to contact you.
I am interested in your 87 style capsule as I'm currently in the process of sourcing parts for Dans D-87.

My questions would be whether you ship to Israel, how would the shipment cost and how much lead time I should expect.

Thanks for your time.
Best Regards,

Moshe Werner

OK another quick update sound clip I wanted to share with everyone. So, I received a call from a studio friend of mine who was lucky enough to have a reissue ElaM 251 in his possession, but the kicker was the fact the owner had a vintage ck12 capsule installed! Needless to say I brought my C12 clone over and we did a quick shootout!
I was pretty pleased with the results. Again chain is Neve pre 16bit 44.1 Radar converters in to pro tools. These clips will also line up in a session if you want to here them that way as well.


https://www.dropbox.com/sh/us8gz1id88bmihz/lVhDA_etvt

Please let me know what you think!!

Dear Eric,

i have a mic with original AKG brass CK12 in Fixed bias C12 headamp.
i have tim's capsule too in elam 251E self bias headamp, and C12 configuration also.
i can tell you that these capsules are very very close to each other, but the sound of the mics is quite different.
We all well know that it's due to the electronic differences inside the mics, and body/head baskets differences too.

So i think that your last shootout is very interesting but not accurate.

your c12 clone is more noisy than the elam...maybe the tube ??

however , your hk12 sounds good to me.

i would a little more low end/low mid to it, it should just add more body to the sound, but please be sure that it doesn't come from the electronics...
if your using a matador C12 pcb for example, please insulate the teflon/high impedance parts to avoid low cut filtering.
i know that epoxy is a bad insulation material for mics...
Please check some various tubes as the inter-electrodes input insulation may vary from one to another.

the HK12 seems a little more sibilant than the original CK12 but it's perhaps due to the head basket difference.

i think that you're close to the Graal, but please use the same body or at least same headamp for your shootouts.

Could you post us a chart for your HK12?

Please keep going , you're so close and you've already done a fantastic job...
Kindest regards
Fred

how?

in the matador c12 pcb, the teflon/metal pins are soldered directly on the pcb.
i think we'd better avoid contact between the metal conductor of the pins, and the pcb.
epoxy is a bad high impedance insulator (in the gig ohms order...)
teflon is the opposite...
like many manufacturers, we should make some "point to point" in the high impedance section.
remember that even a few grid current leak, can badly affect the frequency response.

cheers
Fred

Teflon *is* better, but only in a vacuum.   Remember that the air around the telfon pin is in parallel with the pin.

I did run a frequency sweep through a stock build with a 70pF cap in place of the capsule, and the default build on my PCB is flat down to roughly 40-50Hz.  Increasing the value of C12 helps (as does getting a transformer with higher primary inductance like AMI's T14), but only a few dB down in the 20-40Hz region.

So long as the area around the pins is cleaned well with IPA I don't think it will effect the response of the circuit.

In any case, Eric's capsule sounds fantastic.

Dear Matador,

i understand but the problem is not the air around the teflon, it's the conductor soldered on the pcb.
i think we'd better glue the teflon pin on the pcb and solder the high value resistors straight  to the pin's conductor (easy to do a point to point).

your C12 headamp should be flat from 20hz to 20khz +/-1db with an AMI T14 (oliver's specs)
the 6072a tube is not limiting in this range, the 250 Mohms grid resistance neither
the output cap at 1uf is limiting below 8hz at this impedance
In an Elam 251E, there is by nature some high pass filters : lower grid resistance, output T14/1 by HAUFE (begins to cut below 100hz !!!)
In an Elam 251, the grid resistance is higher and the AC701 has a higher inter-electrode input impedance, thus the pre-transformer headamp is cutting lower than the 251E.

the HK12 sounds fantastic to my ears too, but Eric has asked for our feedbacks so he may think that there's room for some improvements..
I think it lacks of bottom end/body in the last shootout compared to the TFK ELAM (maybe the headamp...?)
but it seems very promising...

Dear Eric, let us know if there are some upgrades...
Could you please post us a frequency chart and some detailed pictures of your hk12 ?

cheers
Fred

A few options come to mind:

Source impedance plays a huge role in determining the pass band.  The output impedance of the tube stage, in combination with the coupling cap and the inductance of the primary, form a normal RLC resonant circuit.  Just spitballing a few numbers here:  with a roughly 40K output impedance (essentially the plate resistor in parallel with rp), a 0.5u coupling cap, and a 150H primary, we have a passband that is 3dB down at about 50Hz.  Cutting the source impedance by half moves the 3dB down point to below 15Hz, which means there would be about 2dB more content below 100Hz.

This could be easily done by simply paralleling both halves of the tube, and running twice the plate current while cutting the plate resistor in half.  Another way would be to convert the tube to a CCDA stage/cathode follower which will cut the source impedance down to less than 1K.

Increasing the coupling cap helps a bit here too:  2u might be a good value for those looking for more bass response.

Additionally, the reflected impedance from the output greatly effects tube loading at higher frequencies:  a high cut might be perceived as a bass boost.  A simple 600ohm resistor across the secondary terminals might bring the reflected impedance down to a point where we start cutting highs a bit for more perceived bass.  It's a 5-minute test in any case.