Topic: AKG ck91 active setup - battery box info/schematics?

[acidjack]

I'm in the process of buying some ck91's to get modded into an active setup.  The Seller and I have found someone (I think) to handle the mod to the caps.  I've discussed with Chris from Sound Professionals about having them make a battery box for me, but they need some more information to do it. 

Does anyone have a schematic that they could send for making the battbox?  How different is a battery box for these things than a normal Sound Pros "SPSB"-series 9v battery box, other than that it'll need 2x mini-XLR inputs?   Is the output for the battbox balanced?  Are the inputs balanced or unbalanced?

I've tried reading all the posts I can find from searching on here, including the stuff on this useful web page: http://www.cs.uwaterloo.ca/~mannr/AKG/
but I'm just not a very technical guy I'm afraid... Any help much appreciated.  I'm also happy to buy a used existing box if anyone has one.

[RhinoJackson]

I think this is what you want.

Those are the capsules in the SP-CMC-8, I believe?  If so, this should do the trick:



The ideal value for R1 depends on the caps - on my stereo pair, the ideal values vary by over 20%.  Something around 30k should be fine, though.
The values for C1 and R2 are not critical - as chosen, the capacitor will give no significant bass rolloff into any reasonable load.  R2 simply prevents the output from having a DC voltage on it prior to plugging in.

Obviously this needs to be duplicated for the 2 channels.

HTH

[EarlyMorningRain]

I got my ck91 caps modded by the user here with the handle of dano420

search him out if you want. he can mod the caps, make the 9v battery box and make/sell you all the cables you'll need

[dano420]

Just saw this thread!

I might be able to make/mod more ck9x and battery boxes but it might be a while. I'm in process of moving and also do not have all the parts needed to make the battery boxes. PM me and we might be able to work out something.

norma023: How are you liking your modded caps?

Peace

[EarlyMorningRain]

Just saw this thread!

I might be able to make/mod more ck9x and battery boxes but it might be a while. I'm in process of moving and also do not have all the parts needed to make the battery boxes. PM me and we might be able to work out something.

norma023: How are you liking your modded caps?

Peace

me likey !!   

I upgraded to a Church 9100 preamp actually, so my battery box is not being used and is for sale......

[aleal5687]

Are you using your 9100 to power your ck91 caps?

I thought that the mic require > 9v and church pre only supplies 8.something

[EarlyMorningRain]

Are you using your 9100 to power your ck91 caps?
I thought that the mic require > 9v and church pre only supplies 8.something

I am using a 9100 preamp with my ck91 actives, so yes.

I have read those same reports from Chris about his preamps only putting out the 8.something. When I asked him about that, he said to send the mics and the batt box to him and he would check it out futher. Skip to the end and he said his preamp would power the ck9x caps just fine.

Sorry for the threadjack.

BTW - It is nice to see other ck9x active users out there all in the same thread though....
 

[HELMI]

hi acidjack,

I'm totally new in this forum and my English isn't very good but perhaps you can use
the information later

helmi