MBHO CK12 Capsule--KA1000N and KA1100?

[C12VR]

Well that capsule is cardioid only so I think the graph must be a very poor representation of 0 degrees compared to 180 degrees.

ah yes you're right. The shape looked similar at first glance, but it's definitely different. Incorrect for sure.

 

[hop.sing]

Your measurement of the MBHO capsule looks correct. They have a bump in the mids which really makes them deviate from an AKG.

That capsule was originally designed to only be polarized to 48v.

Thanks for confirming that the capsule (and my measurement setup) works ok, the mic definitely sounds good.
What is the consequence of the 60v compared to the 48v polarization voltage?
The capsule does not collapse so technically it works.
Since b+ is adjustable in that mics power supply I could lower it just for fun to 100v and have a listen and measure it. The tube should still be happy…
I will try and report.

 

[Tim Campbell]

Thanks for confirming that the capsule (and my measurement setup) works ok, the mic definitely sounds good.
What is the consequence of the 60v compared to the 48v polarization voltage?
The capsule does not collapse so technically it works.
Since b+ is adjustable in that mics power supply I could lower it just for fun to 100v and have a listen and measure it. The tube should still be happy…
I will try and report.

When David Bock first started using MBHO capsules they all collapsed and so he got them to change it so that it could tolerate 60v. I ask that users polarize my capsule to 55v. A 5v drop doesn't lower volume or increase noise but I find that the capsule sounds better at 55v and could extend it's working life.

 

[Tim Campbell]

Just one shipment on my bench today for repair.

 

[RuudNL]

I ask that users polarize my capsule to 55v. A 5v drop doesn't lower volume or increase noise but I find that the capsule sounds better at 55v and could extend it's working life.

The difference between 60 V and 55 V is theoretically 0.8 dB, so this can be neglected.

 

[hop.sing]

When David Bock first started using MBHO capsules they all collapsed and so he got them to change it so that it could tolerate 60v. I ask that users polarize my capsule to 55v. A 5v drop doesn't lower volume or increase noise but I find that the capsule sounds better at 55v and could extend it's working life.

I checked the Microphone and B+ was actually at 128 Volts, so I had 64 Volts on the capsule probably for a long time now. It never collapsed, even on loud sources like 1 meter outside a kikdrum or drum overhead, where I had to Pad the mic to not overload the Preamp, so maybe my MBHO capsule is not the stock one but already modified for higher Voltage. They knew I would put it in a mic with 60V polarisation, so they could have given me a capsule ready for that... I remember talking to Mr Haun on the phone at that time and he was a caring and lovely Person to talk to. I will lower the voltage anyway, because I heard or measured no difference at 115V B+ except 1.3 dB lower Level and that is easily acceptable for me.

 

[paulcheeba]

Up until now I’ve been most impressed with Haun capsule’s in general. The dark Bock one especially. Now I feel that the Austrian Audio are the closest to my original C12’s it’s a shame they don’t make them for DIY. I find others too fizzy, bright and lack depth. It’s frustrating given how easy the centre terminated capsules seem to sound good.

 

[Tim Campbell]

Up until now I’ve been most impressed with Haun capsule’s in general. The dark Bock one especially. Now I feel that the Austrian Audio are the closest to my original C12’s it’s a shame they don’t make them for DIY. I find others too fizzy, bright and lack depth. It’s frustrating given how easy the centre terminated capsules seem to sound good.

Paul I find that interesting. Austrian Audio's own frequency charts show that that capsule doesn't have the same frequency response as a classic brass CK12. They have a peak at 5k and a very deep dip at 8k that the CK12 never had. The peak at 8k is greater than the peak at 11k and there is almost no peak at 10k. I measure vintage capsules all the time, a classic CK12 is pretty flat until just after 2k, has a gentle rise until around 7k, levels off and then rises again until around 11k and then rolls off. I will have to check out this capsule to see why you prefer it's sound.

 

[paulcheeba]

Paul I find that interesting. Austrian Audio's own frequency charts show that that capsule doesn't have the same frequency response as a classic brass CK12. They have a peak at 5k and a very deep dip at 8k that the CK12 never had. The peak at 8k is greater than the peak at 11k and there is almost no peak at 10k. I measure vintage capsules all the time, a classic CK12 is pretty flat until just after 2k, has a gentle rise until around 7k, levels off and then rises again until around 11k and then rolls off. I will have to check out this capsule to see why you prefer it's sound.

It just sounds sweet to me like a real C12. Not brittle or overly bright and sibilant. I don’t look at charts I just listen.

 

[Tim Campbell]

It might be that you like it because it is very similar to the frequency response of a K47 Neumann capsule. They also sound good.

 

[paulcheeba]

It might be that you like it because it is very similar to the frequency response of a K47 Neumann capsule. They also sound good.

Well it doesn't naturally have so much low end and it's not a tube mic but the top end which is where I'm focussed on CK12's is sweet and clear. A small eq adjustment can match them.

 

[cfanzalone]

Hi all,

Does anyone know how to wire a Haun capsule in a DYI mic? I've seen pics that, on the Omni KA1100 both diaphragms go to ground?? If so, how are the Cardioid/Fig 8/Onmi patterns established??

Thanks for any help

 

[Khron]

I've seen pics that, on the Omni KA1100 both diaphragms go to ground

Can you show / link us some of those pics?

 

[cfanzalone]

I don't want to get myself or anyone else in trouble, but were posted:
https://repforums.prosoundweb.com/index.php?topic=22037.0

 

[Khron]

I don't want to get myself or anyone else in trouble, but were posted:
https://repforums.prosoundweb.com/index.php?topic=22037.0

"P.S.: The actual capsule in the KA1000 and KA1100 lollipop is the same of course. In the omni head both diaphragms are connected (to ground), in the cardioid only the front diaphragm is connected. "

As in, if you read what is written (and without other assumptions), that's how things are wired in the complete lollipop head. That meaning the 3-wire capsule mounted in said lollipop head, that mounts onto a body that apparently otherwise takes small-diaphragm capsules.

 

[cfanzalone]

Thank you, I can only assume the amplifier dictates the polar pattern. I've done a few modded mics and usually the backplate goes to ground...is the KA100/KA1100 wired backward polarity?

It may be more than I can chew...

 

[Khron]

I can only assume the amplifier dictates the polar pattern.

In this case, only in the sense that the MBHO one is a single-pattern circuit (hence the need for hard-wiring).

https://www.mbho.de/products03.htm

Not sure any of the mic bodies they have are anything other than single-pattern, so... yeah...

 

[TLRT]

Here is a picture from my collection,top is vintage AKG, down is Mbho:

 

[tomas.borgstrom]

Thank you, I can only assume the amplifier dictates the polar pattern. I've done a few modded mics and usually the backplate goes to ground...is the KA100/KA1100 wired backward polarity?

It may be more than I can chew...

You can do it both ways. Look at the AKG C12 schematics. The front diaphragm goes to ground. The signal is taken from the backplate which also recieves a 60V polarization voltage. The pickup pattern is set by applying 0-120V on the rear diaphragm. You can wire a MBHO CK12 like this or the way you are used to.

Study the capsule connection and polarization in some different classic schematics (for example U47, U48, m49, u67, elam 250, KM56) and I think you will understand it better.

 

[OneRoomStudio]

One thing to think about with capsule polarizing schemes is signal polarity. If you want absolute correlation with acoustic events, you need to make sure that when the capsule is deflected by a positive change in air pressure, that creates a positive voltage swing coming out of the mic. How the capsule is wired, how the impedance converting circuit is wired (most class-A mic circuits are common-cathode/common-source amplifiers and flip polarity), and how the output transformer (if there is one) is wired all matter. Keep track of the polarity!

Taking signal from a ground-potential backplate (relative to a positively-charged diaphragm) will have the opposite polarity of taking the signal from a positively-charged diaphragm relative to a grounded backplate.