Topic: Crazy cheap schoeps actives project

[it-goes-to-eleven]

Goal: Pair of Schoeps CMC6 bodies + actives for $1100 ??  Maybe with Mk4 caps for $1700?

Here's what I'm trying..  This company sells used Schoeps installations from board rooms, lecterns, etc. You get a CMC6, a MK4S (vocal) cap, a 14" semi-rigid active mounting gooseneck and a windscreen.  The color is sorta tan. These have been going for $800-$835. 

http://cgi.ebay.com/Schoeps-MK4S-Microphone-CMC6-Amp-Pro-Audio_W0QQitemZ7343763257QQcategoryZ41466QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

My plan is to hack the gooseneck and replace it with a chunk of mic cable.  I received one of these units and after some testing began dissecting a gooseneck last night. It seems to contain the necessary buffer circuit.  I don't know if this is the same active buffer as found in a KC5.  I also don't know if the circuit will have to be tweaked in order to work well with a somewhat longer cable.

It was necessary to cut the gooseneck to disassemble it safely.  Final removal of the gooseneck from the shells was tricky. I just sweated it out by carefully heating the goose with a propane torch. After some annealing,  I tugged and unwound the first one (it is spring steal and tough). I heated the second a bit more and it came out pretty easily. I was just able to avoid charing the shell paint. I was pretty worried about getting it out without damaging the shells.

I'm having a little trouble finding some 1804A cable to wire these up.. Any source or substitute suggestions would be appreciated.  I have some mini-star quad on hand but I'd like to use something more sexy.

There is also the question of soldering the cable in.. Do I risk soldering the cable to the mounting pad or do I cut and solder to the existing wires?  I'm leaning toward the latter but more concerned about connection quality with that approach.

Here are some pics of the progress.  There are also a couple pics of the CMC6 innards for the curious.

At this point I plan on selling the Mk4S. I don't know what they're worth.  With some help, there's a chance the bass rolloff could possibly be removed.  But I'd need some coaching for that one..  That would Really sweeten this deal.

[dmonterisi]

good luck with the project...+T for ingenuity.  however, you have far larger gonads than me to try this:

It was necessary to cut the gooseneck to disassemble it safely.  Final removal of the gooseneck from the shells was tricky. I just sweated it out by carefully heating the goose with a propane torch. After some annealing,  I tugged and unwound the first one (it is spring steal and tough). I heated the second a bit more and it came out pretty easily. I was just able to avoid charing the shell paint. I was pretty worried about getting it out without damaging the shells.

[gonads]

good luck with the project...+T for ingenuity.  however, you have far larger gonads than me to try this:

agreed

[dmonterisi]

i forgot about 'nads...how's it hanging, bro?

[pfife]

you definately have more guts (and skill) than I, but it would be super tite if that worked out for you!

[dklein]

thanks for the pics - I've always wondered what's in an active cable and JK seems to be gone.  I think I see a resistor, lytic cap, FET, ferrite bead for RF?,  and somethin' else - is that red guy another cap?

[momule]

you can find the belden cable your needing here.
I just picked up 30 ft from them a couple weeks ago.

http://eskc.com/contactus.asp

heres a link to the cable in there catalog.
http://eskc.com/invout.asp?SearchBy=Part&SearchFor=1804a

[JAH]

- is that red guy another cap?

yup....

[dklein]

plan B - just in case
 http://taperssection.com/index.php?topic=48484

[bluegrass_brad]

Nice work!

[poorlyconditioned]

Goal: Pair of Schoeps CMC6 bodies + actives for $1100 ??  Maybe with Mk4 caps for $1700?

Here's what I'm trying..  This company sells used Schoeps installations from board rooms, lecterns, etc. You get a CMC6, a MK4S (vocal) cap, a 14" semi-rigid active mounting gooseneck and a windscreen.  The color is sorta tan. These have been going for $800-$835. 

http://cgi.ebay.com/Schoeps-MK4S-Microphone-CMC6-Amp-Pro-Audio_W0QQitemZ7343763257QQcategoryZ41466QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

My plan is to hack the gooseneck and replace it with a chunk of mic cable.  I received one of these units and after some testing began dissecting a gooseneck last night. It seems to contain the necessary buffer circuit.  I don't know if this is the same active buffer as found in a KC5.  I also don't know if the circuit will have to be tweaked in order to work well with a somewhat longer cable.

It was necessary to cut the gooseneck to disassemble it safely.  Final removal of the gooseneck from the shells was tricky. I just sweated it out by carefully heating the goose with a propane torch. After some annealing,  I tugged and unwound the first one (it is spring steal and tough). I heated the second a bit more and it came out pretty easily. I was just able to avoid charing the shell paint. I was pretty worried about getting it out without damaging the shells.

I'm having a little trouble finding some 1804A cable to wire these up.. Any source or substitute suggestions would be appreciated.  I have some mini-star quad on hand but I'd like to use something more sexy.

There is also the question of soldering the cable in.. Do I risk soldering the cable to the mounting pad or do I cut and solder to the existing wires?  I'm leaning toward the latter but more concerned about connection quality with that approach.

Here are some pics of the progress.  There are also a couple pics of the CMC6 innards for the curious.

At this point I plan on selling the Mk4S. I don't know what they're worth.  With some help, there's a chance the bass rolloff could possibly be removed.  But I'd need some coaching for that one..  That would Really sweeten this deal.

Cool!  That looks like what the AKG CK91/92/93 actives use.  Well, those ones have the FET inside the capsule itself, but it looks like a similar board that you have in the connectors: two resistors plus a FET.

I'm guessing there should be no trouble getting a longer cable.  I'm using a 20' cable on my CK93's.  Also, one thing worth considering is powering the Capsules+FET directly with a battery box.  This could lighten your load for stealthing.

So, this brings me to the quesiton: What is all that stuff in the body?  I see a 14 pin DIP chip there.  Can you tell me the number on this?

Anyway, great hacking!
  Richard

[dklein]

There is no plan B, you doubter! 

Nice work!  I guess Plan B thinking is based on *my* hacking experiences 
Post a sample!

[it-goes-to-eleven]

Nice work!  I guess Plan B thinking is based on *my* hacking experiences
Post a sample!

Thanks!  It was a tough project and the risk of failure was high..  Especially after I went public on ts with my effort before it really began.. Nothing like a little extra pressure.

[dklein]

sounds good!  I'd love to hear something with a full band when you get it.

[it-goes-to-eleven]

Here's a decent diagram of the innards of the active cables..

http://www.posthorn.com/S_parts.html

My config is very much like that except it does not include ZS 21-3 (I think it is for a special version) and CD 3/4-4C is threaded in rather than held by screws.