K47 in C12 build

Hi Guys

So, I had this old C12 build from years ago floating around. I finally got around to build it. It has to be said that I am no tech-master, I can solder things and know how to follow good instructions, so bear with me..

I'v always wondered how a K47 capsule would sound in a C12 kind of circuit. What would it take to make the C12 Circuit and a K47 play well together? Is it even possible?

I couldn't find the answer through the search-function, I hope some of you have some experience and input on this.

If all fails I'll just get the TC CT12 capsule, but I would really love to hear the K47-C12 combo.

Thanks in advance!

Why wouldn't they "play well together"?

The circuit doesn't care what capsule's connected to it, and the capsule doesn't really care what circuit it's connected to.

The only difference will be the different frequency response of the capsule (K47 vs. CK12).

That was my initial thought, but experience tells me that is might not be that simple?..

Should any of the calibration be different with a K47 instead of a CK12 capsule?

Jkidazz said:

...Should any of the calibration be different with a K47 instead of a CK12 capsule?

Click to expand...

The only possible issue I can think of is with the level of polarisation voltage. 
I  did have a problem once with a 3 micron C12 type capsule which didn't like being connected to a circuit  which had a 60V polarisation voltage. 
Reducing that to 50V cured the problem.

It's not going to be a problem the other way round .... if your current circuit is designed to work with a C12, then a K47 should just be a drop in replacement...

rogs said:

The only possible issue I can think of is with the level of polarisation voltage. 
I  did have a problem once with a 3 micron C12 type capsule which didn't like being connected to a circuit  which had a 60V polarisation voltage. 
Reducing that to 50V cured the problem.

Click to expand...

(Thread hijack) @rogs what was the issue you had with 60v polarization? I'm having some trouble with a G7 build with a single sided C12 clone capsule. (inexpensive WGT).

I get low sensitivity and a lot of hum at 100v B+ (that's the PSU for my "royermods") and no signal and only buzz at 160v B+.  I'm in the middle of troubleshooting.

Blue Jinn said:

(Thread hijack) @rogs what was the issue you had with 60v polarization? ....

Click to expand...

I had fitted a 3 micron 34mm edge terminated capsules to a version of my LDCX2 project  (see here: http://www.jp137.com/lts/LDCX2.notes.pdf ) . The schematic shows a voltage multiplier that provides a 60V polarisation voltage, which had been used with the original K67 type capsule without any problems.

The 3 micron C12 style capsule  ( see here for original capsule ebay listing:  tinyurl.com/34mm-3micron ) turned out to be quite lot more sensitive than the original K67 (about 6dB) , but after the mic had been on for a few hours, the output became much lower, and seriously distorted .. No hum problems though...

I removed the head basket and could immediately see that the capsule membrane  looked to be a little bit 'dimpled' (bit like a golf ball - although much shallower dimples!)

I decide that the capsule had partially collapsed, and was (possibly) damaged beyond repair.
However, I disconnected the power, and the 'dimples' disappeared.

I decided to remove C8 from the voltage multiplier, which had the effect of reducing the polarisation voltage to c.50 V

The mic returned to it's original  quality output, and I've had no further issues.....

The drop in polarisation voltage did drop the sensitivity, but only by couple of dB.....
 

That happened to me once as well, with 60v and Rayking CK12.

BTW, thank you Rogs for the marvelous idea with end address capsule holder!

kingkorg said:

BTW, thank you Rogs for the marvelous idea with end address capsule holder!

Click to expand...

Seems to work quite well, with good directionality.  (The BM800 headbasket allows quite good access to the rear of the capsule)

Originally created for a friend as an alternative to the Rode Broadcaster, which  he  couldn't afford!