KM84 Circuit with AKG CK61

I saw the below post, and was thinking it sounds like a good project for me.  I have a KM84 with a mutilated body, no capsule, and pair of brand new KM88i bodies sans guts.  It looks like I should be able to mount the CK61 on the end of the KM88 with some kind of threaded ring or some other home fabricated solution.

I found a schematic for a C460B that seems to indicate that the polarization voltage on the CK61 is ~10V, whereas on a KM84 it looks like it's ~40V.  Does anyone know if the CK61 will be able to handle the higher voltage, or should I step it down?

dale116dot7 said:

I did make up one SDC capsule. It was a lot harder than LDC's. After I recover my sanity from the last M7 run, I might do some side-address smaller capsules - kinda like the ATM450 or a single-sided version of the CM7156. I don't like doing double-sided capsules that much any more.

I've made the KM84 circuit and used it on an AKG CK61-ULS capsule. Sounds nice. I used a Beyer transformer. Those capsules are reasonably priced (around $300) considering how good they sound. On my recommended capsule list. Gus, have you tried them?

-Dale

Click to expand...

Alright, it looks like the diagrams I was looking at are erroneous.  Does anyone know what the polarization voltage is for the C480B/CK61 is?  The Neumann docs show 46v on the capsule.

Thanks.

40V is fine on CK61.  Maybe as much as 60V as long as it doesn't collapse.

KM84 will always have less than 48V so OK.

Cool.  I also found a C480B service manual that shows 62V on the CK61 (attached below in case someone else is looking for it).  So 20*log10(46/62) ~ -2.5dB.  Should be totally in the range.

A few weeks ago, I put a c460B service manual up in the tech documents section:

http://groupdiy.com/index.php?topic=44737.msg712802#msg712802

I'm interested in your idea.  I've been thinking about trying to build a Schoeps-type circuit for these capsules.  Looking forward to watching this thread 

Does anyone know whether that CK61 capsule has an isolated backplate and diaphragm?

Thx,
jonathan