Topic: The Answer on the Schoeps powering question..

[RebelRebel]

The orginal thread was locked. My engineer buddy, Vollmer at schoeps sent me this response:

A schoeps capsule requires 60V phantom power to operate at full
sensitivity and dynamic range.
Yes.

A CMC6 microphone body does a DC to DC conversion where 48V are
converted to 60V to bring the capsule to manufacturers specs for full
sensitivity.
No. The CMC6 does not convert "48V" to 60V. A CMC6 works with 12V or
48V. In both cases there is a loss of voltage at the powering resistors
(example 6k8 at 48V). So the CMC6 only gets about 33V (@48V) or 10V
(@12V). It creates internally a stabilized voltage of about 6.5 Volts.
These 6.5 Volts are converted to the polarization voltage of stabilized 60
Volts
 
A VMS pre amp provides 60V of power at the microphone capsule when used
with a KCY/KC5 system and no CMC6 bodies.
Yes.

The sonosax may be modified with a 5 pin (I think its 5) 'active'
system that will enable the sonosax to provide the 48V phantom power to the
capsules.  48V phantom....what?  Thats right.  This results in that
flat non existant transition between all frequencies recording that just
doesnt sound "LIVE"
When you connect the MK capsules to the Sonosax with 48V powering they
will have a 1.9dB lower sensitivity - that`s all.[/b]

[stober]

thanks. + t

[Brian Skalinder]

Hah...thanks for posting this, Teddy.  I just received the damn near exact response.  Bottom line:  if the SX-M2/LS2 does, in fact, provide only 48v to the caps, the only repercussion is 1.9dB lower sensitivity.  In other words, it's a non-issue.

[JasonR]

BTW - I'm happy to measure the DC voltage supplied to caps by the SX-M2/LS if someone can guide me across which two pins I should be measuring.  Presumably this can be done (carefully) with the caps connected by measuring DC voltage across the correct two pins.  I posted internal pics of the SX-M2/LS along with a KC5 cable schematic along with the modification needed for SX-M2/LS use here: http://taperssection.com/index.php?topic=56144.0

- Jason

[fozzy]

FYI for neumans to achive -10db atenuation via the switch on some mics they reduce the voltage by 1/3. 

[RebelRebel]

Sorry to post in the wrong forum , Mods..thanks for the move.

[JasonR]

Just happened to stumble across this while looking at my Schoeps catalog tonight.  There's a block diagram of the VMS 5 U mic preamp and it shows the KCY cable receiving two voltages...

+6V
+58V

I *think* I know how to test the voltage on the Sonosax, but I'm not sure I'm brave enough.  I own the Sonosax in part because my Beyer MV100 went up in smoke, but that's another story...

- Jason

[dgodwin]

Just happened to stumble across this while looking at my Schoeps catalog tonight.  There's a block diagram of the VMS 5 U mic preamp and it shows the KCY cable receiving two voltages...

+6V
+58V

I *think* I know how to test the voltage on the Sonosax, but I'm not sure I'm brave enough.  I own the Sonosax in part because my Beyer MV100 went up in smoke, but that's another story...

- Jason

I remember the story.  You bought a 9v battery from duracell that had the + and - terminals labeled in reverse.  No questions asked, they just cut you a check... (did I remember it right?)

[JasonR]

That's some good memory... you should win a prize or something.

It was a CVS battery actually, but as I found out after reporting the incident to CVS, Duracell OEM's their batteries.  Duracell came through with a $600 check days after receiving my MV-100 in a prepaid UPS mailer that they provided.  Awesome company... I'm sold on Duracell batteries for life.

- Jason

[ianstone]

That's some good memory... you should win a prize or something.

It was a CVS battery actually, but as I found out after reporting the incident to CVS, Duracell OEM's their batteries.  Duracell came through with a $600 check days after receiving my MV-100 in a prepaid UPS mailer that they provided.  Awesome company... I'm sold on Duracell batteries for life.

- Jason

and that's why they did it. They knew you were a valuable customer as a user of high quality electronics, they've probably already gotten their $600 back