AKG C12 / Siemens SM204 help needed

[micaddict]

Man, you're fast! 

Anyway, are you liking the side effects your question is causing?

 

[Tim Campbell]

From what I understand, if and when Andreas builds in very small numbers, he tries to source the original parts first. I know the SM204s he made have original transformers. So they may have original CK12 capsules too, though maybe not period correct. (?)

From my own discussions with Andreas he was very clear that he preferred the sound of the MBHO capsule and modern brass CK12's over the early type.

 

[TLRT]

Man, you're fast! 

Anyway, are you liking the side effects your question is causing?

Yes this helps a lot, I think this is the only mic in my country(my serial is 23x?), so I don't have anybody to ask here about the details. Thank you everybody! I'll post the results here when I'm ready.

 

[micaddict]

From what I understand, if and when Andreas builds in very small numbers, he tries to source the original parts first. I know the SM204s he made have original transformers. So they may have original CK12 capsules too, though maybe not period correct. (?)

From my own discussions with Andreas he was very clear that he preferred the sound of the MBHO capsule and modern brass CK12's over the early type.

OK.

What is your opinion if we leave out MBHO?

 

[Tim Campbell]

I work on CK12 capsules of every variation everyday. I think they all bring something good of their own to a microphone and I like all of them.
After having built more than 2000 of my own capsules my preference is a little obvious

 

[micaddict]

I work on CK12 capsules of every variation everyday. I think they all bring something good of their own to a microphone and I like all of them.
After having built more than 2000 of my own capsules my preference is a little obvious

Yes, we can guess how you think about your own and no one is blaming you.
On the contrary. 

But I was hoping you'd elaborate a bit (more) about the early versus later, original CK12s.

 

[Tim Campbell]

I think they all bring something good of their own to a microphone and I like all of them.

 

[micaddict]

Not much wiser, but the message is clear. 

 

[OPR]

  I think they all bring something good of their own to a microphone and I like all of them

I agree  100% with Tim.
The hardest part about having  such maluable  capsule design is deciding and settling  on a tuning  point as another sonic variation is a few khz or 5 micron away! But this is also a very powerful  thing if  you are to be specific how you want a capsule to sound...
AKG obviously  battled  with this over the years.

 

[Matt Nolan]

Wow! Great thread!! 8)
They always get interesting when Micaddict gets involved 
The sm204 schematic looks like the mic would sound more like a 251 then a c12 looking the biasing scheme

You are right, but I would offer also  a lot of the difference in sound between a 251 and a C12 sound comes from the different diameter headbaskets and the mild standing wave colouration therein.

 

[Tim Campbell]

You are right, but I would offer also  a lot of the difference in sound between a 251 and a C12 sound comes from the different diameter headbaskets and the mild standing wave colouration therein.

I feel it has a lot to do with the double layer of mesh in the 251.

 

[OPR]

You are right, but I would offer also  a lot of the difference in sound between a 251 and a C12 sound comes from the different diameter headbaskets and the mild standing wave colouration therein.

I totally agree  8)It's definitely another big factor!  ;D

I've built plenty of mics and done a lot of experimentation by switching between biasing schemes and found huge differences in the behavior of the amplifier and the resultant sound of the mic  even with everything else "Headbasket"etc being the same. Swapping the head basket alone on a c12 for a 251 style will not make it sound like a 251 or visa-versa although it will would help 

 

[micaddict]

OK, so how about it?

- dual mesh headbasket
- CK12 style capsule, tuned for (relatively) enhanced mids.
- SM204/C23 circuit
- point-to-point build
- big tranny (Samar?)

Anybody getting the itch, yet?

 

[granger.frederic]

bigger tranny is not necessarily better
we must take care of the impedance matching
Ct12 is known for its low end extension and works very well with "small" AMI/Haufe/cinemag/etc T14 or T14/1 type
but it's just a matter of taste and desired result
however i like Samar's xformers a lot ...

 

[micaddict]

bigger tranny is not necessarily better
we must take care of the impedance matching
Ct12 is known for its low end extension and works very well with "small" AMI/Haufe/cinemag/etc T14 or T14/1 type
but it's just a matter of taste and desired result
however i like Samar's xformers a lot ...

He'll chime in himself, but I believe In76d has a preference for smaller transformers in those, too.

Interesting point. I'll think out loud if I may. Feel free to correct me or to add.
- Extended lows is not the same thing as boosted lows.
- Also, a more mid strong capsule could balance things out.
- And you can always roll off lows if you don't need them, e.g. for vocal applications (I'm a singer myself, so i'd primarily use it for vocals anyway). But the other way round, i.e. amplifying what might not be not there with a Haufe T14/1, would mean less versatility (orchestral work).

In any case a 12:1 ratio, no?

Yeah, I have a weak spot for the Samar trannies, too. 

 

[Tim Campbell]

As a male singer, unless you like the airy Peter Gabriel type sound, a microphone that leans a lot more heavily towards a U47 would probably be preferable. Even I prefer a U47 on my own voice.

I also really like Mark's transformers. I also have some from Max that sound incredible but they are large and very expensive.

 

[granger.frederic]

i would say around 12:1 for a 6072a (plate follower) and between 10:1 and 12:1 for Ac701

 

[micaddict]

Tim wrote:

As a male singer, unless you like the airy Peter Gabriel type sound, a microphone that leans a lot more heavily towards a U47 would probably be preferable. Even I prefer a U47 on my own voice.

I'm a bass-baritone FWIW.

I have a U47 copy and an original U67, among other mics. Hey, I'm an addict so I can't help it.
Also, there's something really nice in the works that will wear your capsule. More about that later.

U47 is nice for crooning and such. Think Sinatra. But to my ears it can be a bit metallic or telephonic sounding if that makes sense. M49 is smoother.
Edge terminated is more open, natural and hifi sounding to my ears (but can lack some mid punch, depending on application and need).
The U67 I will defend with my life.

I have a locker, so I myself don't need a mic that covers all grounds.
But if it can be done with a CK12 capsule then I want to know everything about it.
It is stronger than me.  ;D

Here's a quote from a guy who has used them all:

I used to have akg C12 and also Sm204. ( now own a pair of Siemenses) . I like Siemens much more it has open end of C12 and body of Elam. C12 worked for high man Voices and for sopran female. C12 was quite easy to overdrive. Siemens not so easy and works for much more types of voice.

 

[micaddict]

i would say around 12:1 for a 6072a (plate follower) and between 10:1 and 12:1 for Ac701

Thanks.

How about a 12AT7/6201?

 

[granger.frederic]

12AT7/6201 has lower output impedance ,  i would choose a transformer around 9 or 10:1