a good mic to mod to my ck12 and k67

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Gabriel Sousa

Well-known member
Joined
Jun 8, 2004
Messages
80
Location
Leiria, Portugal
hello ppl,

i have two nice capsules, ck12 and k67.

can you give me a mic to make a mod to ck12 or k67.

is the circuit of apex 460, is good for one of them ?

thanks a lot
 
K67 has inbuilt HF boost. You basically MUST use the Neumann-style rolloff circuit which it was designed to work with.

The CK12 should be an excellent candidate for a G7.

Keith
 
i dont have the hands to build a mic

[quote author="SSLtech"]K67 has inbuilt HF boost. You basically MUST use the Neumann-style rolloff circuit which it was designed to work with.

The CK12 should be an excellent candidate for a G7.

Keith[/quote]
 
If you make a few modifications to an Apex 460, the CK12 should work nicely with that mic. There are good discussions on this site, the EVE Recording Forum, and the HomrecordingBBS about this mod.

A few of the Chineese mics have the HF roll-off in their circuits that might be suitable for the K67. A few MXL models I think, but I'm not sure which ones.
 
craigmorris74

Do you happen to have links to those forums for those mods ?
 
I took a fast look at the thread.

IMO some questionable information in that thread.

sometime removing grill mesh makes thing worse


To the question

CK12
For the 460 Min parts change.
Install the capsule in the 460 change the tube to a NOS 12at7 and try it stock. Drop the heater voltage to around 5.8VDC at the microphone with a 12at7(not a 12ay7,6072a there is a reason(s) for this) a good voltage to be at for that tube. The stock power supply is not bad multistage RC filtering on the B+

Next change the caps If you want. First one I would change, tube output to the transformer replace it with a film(to taste/what you like) at 250VDC or greater.

I would worry about the microphone transformer last, it has a bigger core than the 2001s and v67s etc so even with what ever lams it uses it is not that bad.

K67 MXLs like the 2001 v67m circuits or other china microphones with that type circuit Like Keith posted.
 
Hi,

I'm surprised there is no mention about the B+ value and/or the polarization voltage.

The CEK12 likes to see between 60-64 volts...

There are different stock values for the 460 (or copy of the 460) : 133, 154, 182 volts at B+ which give respectively 66.5 Volts, 77 volts, 91 Volts at the capsule.

Why the "Chinese engineer" did chose to increase the voltage at B+ ?
It's a kinda copy of C12/C24 which had 120 Volts at B+

Because of the 12Ax7 ? The cathode follower they add ? The capsule they used ?

Thanks,

eD
 
I agree that polarization voltages are important and sound tests are important.

I've read all the threads over and over and I don't know how anyone can be successful moding a mike with so many varied opinions. No one seems to agree on anything. What a #%&%^$ mess. A merry-go-round of confusion.

can there be a list of mics with just good decent mods as a base starting point.... ? and a list of component values to adjust for particular tonal taste. I noticed most threads start in this direction then lose focus as they turn into debates.

example :
apex 460 - mod schematic
nady 1050 - mod schematic

Gus really is the guy who seems to understand this.

lastly, leave the speculation out of it and deal with facts, not what if's and maybe this or maybe that.

there is nothing that bugs me more than a over-hyped mod that really does'nt do anything great for sound of the mic. Subtle changes are'nt worthy of hype. It can really be a waste of time and money. Leads people down the wrong path.

KEEP IT SIMPLE - this is a nightmare for new comers
 
[quote author="maxwall"]I've read all the threads over and over and I don't know how anyone can be successful moding a mike with so many varied opinions. [/quote]

No more consistency should be expected than the consistency within opinions for commercially manufactured mics. In fact, the opinions for commercial mics are probably more consistent because people with a tin ear can fall back on a price tag or step in line with history/conventional wisdom. Then of course there is simple subjectivity. I really don't like ribbon mics or plate reverbs. Many here whom I respect do not share my opinion. It's the same with mic mods. You aren't going to find the magical universal answer on the internet, but you will find some options to try for yourself.

-Chris
 
[quote author="Emperor-TK"][quote author="maxwall"]I've read all the threads over and over and I don't know how anyone can be successful moding a mike with so many varied opinions. [/quote]
No more consistency should be expected than the consistency within opinions for commercially manufactured mics.[/quote]
Amen to that.

To make matters worse, one of the things that makes a cheap mic cheap is poor QC. While some issues are systematic, a mod that helps one mic may well hurt the next one.

JDB.
 
There are a number of things you need to ask before you change stuff in a microphone.

First what do you want to spend? This can set what parts you replace because of cost.

What do you like and dislike with the microphone as it is now?

Then you need to teach yourself what happens with tube at low B+ and higher B+ and different plate currents and different heater voltages.

Then if there is a cap from capsule to grid understand why this cap type can make the most difference with cap types in microphone circuits. This is TASTE no best cap here sometimes I like the stock ceramic in some microphones.

Then measure a bunch of tubes for what matters in tube microphone. You need to figure out what matters is it miller cap or is it gain or is it the oxides or is it ...........

Then the "MAGIC" of the tube microphone is the tube circuit to transformer section and what is sometimes overlooked what it is driving. This part you need to do some learning, reading, building, buying and testing stuff.

Yes capsule voltage counts it is one of the last parts adjusted when I work on a build. Think about it, capsule voltage affects tension due to electrostatic attraction and more voltage can mean more signal to the amp section and.........

NO easy answers no paint by number.
 
thanks GUS,

I think to setup a plan how to work through this circuit makes sense.

I'm about to start a mod on a similar mic than the 1050. Grill is more flat on the top and the body is longer than 1050. It looks like an excellent donor: Golden Age Project TC1

I have a dale m7, a flea m7 holder/mount, a haufe t14/1, a few wima's and tubes.


I will setup a microphone stand in front of my speakers and play always the same music on the same level and record every step I work on the mic.

I know how I fool myself and make me think something sounds better because I changed it,
I'm going mount the dale m7.
record
Change the output cap.
record
Change the tube.
rec
Change the tx to Haufe T14/1 ...this might force me to mod the circuit quite a bit.

.. maybe experiment with polarisation voltage

thats my plan.

I try to do a documentation.

nicholas


TC1_s.jpg
 
[quote author="Gus"]

Yes capsule voltage counts it is one of the last parts adjusted when I work on a build. Think about it, capsule voltage affects tension due to electrostatic attraction and more voltage can mean more signal to the amp section and.........
[/quote]

I don't have the 1/1000 of experience you have in modding microphones, but I'm just wondering why this is the last part you adjust.

Is the capsule not the more important part in the microphone ? I mean this is the part which transforms the air vibrations into voltages variations ? (And the body and the grill have a lot of influence too because they create "acoustic disturbances")

The voltage polarization of a capsule influences its output but also the way it sounds, doesn't it ?
I've read here that a capsule tends to 'harden up' with too much polarization voltage applied, and gets increasingly ugly in the mid-range. I imagine, maybe erroneously, that it would have consequences in the basse frequencies too --> less bass ? :roll:

Why not start by giving the ideal/optimal polarization voltage the capsule has been designed for, or has been proved to work the best with ?

Maybe It's more true when you change to stock capsule for another one (other brand, othe type). [/url]

I would be curious to have your opinion...

Thank you,

eD
 
I just spoke to an old GDR Tonmeister and he doesn't think polarization voltage effects sound much, BUT the higher the voltage the better the SNR.

He suggested up to 80 volt for a m7

nicholas
 
AFAIK the M7 is designed for 60V.

I recently had the chance to see the Neumann labs, and they also showed me their polarization voltage testing rig. They fired up a K87. At about 120V the diaphragm hits the backplate. The operating voltage isn't necessarily half the maximum voltage but it gives you a ballpark figure. Of course you want good SNR (higher voltage) but you also want high SPL handling (lower voltage).
 
[quote author="Rossi"]
I recently had the chance to see the Neumann labs, and they also showed me their polarization voltage testing rig. ).[/quote]

:shock: Lucky you !!! :evil:


[quote author="Rossi"]
They fired up a K87. At about 120V the diaphragm hits the backplate. The operating voltage isn't necessarily half the maximum voltage but it gives you a ballpark figure. Of course you want good SNR (higher voltage) but you also want high SPL handling (lower voltage).[/quote]

John Peluso told me about the polarization voltage for the CEK12 :

62 volts is the "ideal" and 80 to 85 is the max with 100 volts being able to perforate the diaphragm.

eD
 

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