AKG CK-91/2/3 caps question... Blueline active setup, pictures enclosed.

[poorlyconditioned]

I'm considering a DIY "active" setup.  In particular, based on the AKG schematic, I suspect that the CK-9x caps contain both the FET and the (prepolarized) mic element.  *If* this is true, I think they should run off something really simple like a battery box.

Has anyone out there examined their caps/bodies closely?  If so, how many conductors are there on the connector between the caps and the body (including the shield).  It would be even better if somone could take a close up picture .

I know this isn't a DIY/hacking group, but this is the place to find gear!

Thanks for any help,
  Richard

[noahbickart]

I think the problem is the "bayonet" style connector- It's really hard to see any connections in there. However, If you figure something out I am very interested.

-Noah

p.s. anyone who has never hear exactly how good the blue line can sound- check this out:

http://bt.etree.org/details.php?id=14518

Marc Ribot, John Medeski, Chris Wood, Kenny Wollesen & DJ Logic
Bowery Ballroom; New York, NY May 22, 2005
Source Info: akg ck93 (hypercard)> akg se300b (x/y 90)> Tascam Da-P1 @44.1 kHz
Clamped to the floor of the Balcony, left of center.

Transfer Info: Master Dat> Tascam DA20mkII> Marantz Dr-700> EAC> .shn

Mastered & Transferred by Noah Bickart [noahbickart@post.harvard.edu]

[johnw]

This issue was discussed by Jon at jklabs. A search should turn this up. If I remember correctly, a battery box would work, but you would have to hard wire the box to the capsule as the bayonet style connector would be hard to fabricate.

[poorlyconditioned]

This issue was discussed by Jon at jklabs. A search should turn this up. If I remember correctly, a battery box would work, but you would have to hard wire the box to the capsule as the bayonet style connector would be hard to fabricate.

Thanks. I found the thread.  It looks like this is easy and it has been done.  I'll report back here if I try it.  +t to both repsondents.

  Richard

[noahbickart]

any news on the project?

-Noah

[poorlyconditioned]

any news on the project?

-Noah

Not yet.  I ordered the capsules.  I'll post when I get them...

  Richard

[poorlyconditioned]

any news on the project?

-Noah

Alright, the project was succesfull!

I bought two CK93 (hyper) caps.  I posted on the AKG service board and got a *very* prompt reply from Karl@AKG.  This has been done before.  He gave me tech drawings of the caps and even a schematic for the battery box.

OK, after some mechanical tinkering I was able to solder three short wires and get them out of the capsule through the bayonet connector.  The three wires are: +battery, audio, ground.  Then I soldered a lav. mic cable with a 3-pin mini XLR.  My battery box has two 3-pin mini XLR sockets on it and goes to a 1/8" male plug.  It works great!

Send me a PM if you want to do this.  It is not hard, but can be a bit tricky on your first time.  I'm sure I could improve the mechanical construction too.  Right now I've got got hot melt glue and covered it with shrink wrap.  Not too professional, but it works great.

I'm still testing, comparing these to my standby AT853 (H/C/O) caps.  I think they are better, but I don't know how much better.

  Richard

[jeromejello]

pictures?? 

[johnw]

Could you post a link to the thread on the discussion board? Would it be possible to wire the capsule to a female mini XLR connector mounted to a copper tube, then run mini-XLR to XLR cables for 48V phantom powering? Pictures would be awesome BTW.

Sounds like a new mod for Leegeddy ala the Nak mod, unless you want to take this on yourself and make them for other people..

EDIT: http://www.akg.com/akg_structuretree/forum/topics//powerslave,_detail,1,id,1179,_language,EN,nodeid,4,mynodeid,105.html
Do you mind passing along what he told you in the email?

[johnw]

http://www.akg.com/products/product_tipps/powerslave,mynodeid,7,nodeid,1,id,24,_language,EN,pid,232,_view,tips.html

Wonder if this would still be available? This sounds exactly like what you are trying to do, but premade!

[poorlyconditioned]

pictures?? 

No pictures, sorry.  I don't have easy access to a camera right now.  But I *will* make the documentation available.  It is direct from AKG, both the tech drawing and the suggested battery box.  (URL below).

I don't want to do mods for others (no time to do it).  If Marc (leegeddy) wants to great.  I trust him, both in doing great work and in charging a fair price.  So, yes, go for it!  By the way, please DO NOT attempt this unless you are comfortable hacking and you know about phantom vs. electret powering.   (Like AT853 hacks you'll need an adaptor, like SE300B, for phantom power.  This is a battery powering solution only.)

  Richard

URL to AKG spec sheets.  I'll keep these on my webpage for a while only, so grab them if you want them!  Buy AKG stuff, 'cause they gave me great support!
  www.cs.uwaterloo.ca/~mannr/AKG
(exact URL needed, no path given on my main work page.)

[johnw]

Permission denied error on the 300 schematics. Thanks for doing this! I think these pdfs should go in archive here.

[poorlyconditioned]

Permission denied error on the 300 schematics. Thanks for doing this! I think these pdfs should go in archive here.

Fixed.

[noahbickart]

Someone should get on this mod train. I bet there are a number of Blueline users who would love an active setup.

-Noah

[poorlyconditioned]

pictures?? 

OK, here are the pictures!

The capsules with cables out the back (2 wires plus shield, to battery box):


Flying the mics:


My mechanical construction is terrible.  But it *can* be done.  As I said earlier, the detailed mechanical and electrical drawings are from Karl @ AKG, and I've put them at:
http://www.cs.uwaterloo.ca/~mannr/AKG

Enjoy...
  Richard