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Gear / Technical Help => Microphones & Setup => Topic started by: JasonR on January 30, 2006, 09:59:12 PM

Title: Schoeps CMC3 + CMC5 + active cable schematic found
Post by: JasonR on January 30, 2006, 09:59:12 PM

I stumbled across a complete CMC3/CMC5 schematic which includes details on both ends of the active cables (check out the left half when printed - C2, R3 on the body side of the active cable, T1, R1, R2, C1 on the cap end.)  This may be helpful to those trying to engineer alternate active solutions.

To the DIYers, please keep us all in the loop on what you come up with!
 
I grabbed it here: http://www.omnipressor.com/MicSchLib/Schoeps.pdf and am including it as an attachment in case that link should every disappear.

- Jason

Title: Re: Schoeps CMC3 + CMC5 + active cable schematic found
Post by: it-goes-to-eleven on January 30, 2006, 10:38:14 PM

Whoa!  Keep stumbling. Funny how this is just page 79.  Looks like there are some other goodies there.

Title: Re: Schoeps CMC3 + CMC5 + active cable schematic found
Post by: poorlyconditioned on January 30, 2006, 11:50:47 PM

Quote from: Jason Reiser on January 30, 2006, 09:59:12 PM

I stumbled across a complete CMC3/CMC5 schematic which includes details on both ends of the active cables (check out the left half when printed - C2, R3 on the body side of the active cable, T1, R1, R2, C1 on the cap end.)  This may be helpful to those trying to engineer alternate active solutions.

To the DIYers, please keep us all in the loop on what you come up with!
 
I grabbed it here: http://www.omnipressor.com/MicSchLib/Schoeps.pdf and am including it as an attachment in case that link should every disappear.

- Jason

+T.  I've seen this over at micbuilders (Yahoo group) too.

The circuit in the body is really clever too, a dual transistor pair to drive a balanced line.  This now a standard in all modern, so-called "transformerless" mics.

  Richard

Title: Re: Schoeps CMC3 + CMC5 + active cable schematic found
Post by: flipp on January 31, 2006, 12:01:00 AM

Can one of the moderators please place this in the archive?

Title: Re: Schoeps CMC3 + CMC5 + active cable schematic found
Post by: JasonR on February 03, 2006, 08:45:41 PM

Here are some CMC5 internal pictures that I took today.

- Jason

Title: Re: Schoeps CMC3 + CMC5 + active cable schematic found
Post by: it-goes-to-eleven on February 03, 2006, 09:02:18 PM

That cmc5 is sparse.

There is a lot going on in the cmc6.  Some due to it supporting 12volt for phantom and some maybe due to it going down to 20 hz where the cmc5 rolls off below 30.

http://www.schoeps.de/E-2004/cmc.html

Title: Re: Schoeps CMC3 + CMC5 + active cable schematic found
Post by: JasonR on February 03, 2006, 09:06:44 PM

The CMC3 (+12V phantom) is identical inside save for an extra bridge across a resistor on the rear.  I'm told the CMC6 has superior noise rejection compared with the CMC3/4/5 units, so some of that more complex circuitry must be responsible for that as well.

Testing side-by-side between the CMC5 and CMC6, I can't hear any difference at all just speaking, singing, whistling, etc into them.  YMMV.

- Jason

Title: Re: Schoeps CMC3 + CMC5 + active cable schematic found
Post by: poorlyconditioned on February 03, 2006, 09:19:03 PM

Quote from: Jason Reiser on February 03, 2006, 08:45:41 PM

Here are some CMC5 internal pictures that I took today.

- Jason

T++.  Thanks for the pics!

Elegant, efficient design.  Beautiful!  Quite a contrast to the "overengineered" AKG 480.  Certainly a different design philosophy.

  Richard

Title: Re: Schoeps CMC3 + CMC5 + active cable schematic found
Post by: JasonR on February 03, 2006, 09:45:08 PM

Quote from: poorlyconditioned on February 03, 2006, 09:19:03 PM

T++.  Thanks for the pics!

Elegant, efficient design.  Beautiful!  Quite a contrast to the "overengineered" AKG 480.  Certainly a different design philosophy.

No prob - glad to help!

BTW - keep in mind that the CMC3/4/5 were first sold in 1973.  The C480B appeard just a few years later in 1996.  ;)  The C460B came out in 1983.  I've never seen inside either a 460 or 480 personally.

- Jason