Topic: VMS-5U, KCY, & phantom power

[page]

The "Lemosax" uses a DC converter that steps up the battery voltage directly to the ~60 Volt polarization voltage that the capsules require; the current draw is next to nothing, so that can be done quite efficiently. The operating voltage for the FETs in the cable demands somewhat more current, but the voltage doesn't require any step-up; it can be derived very simply from the preamp's own DC supply.

I thought the lemosax ran at 48v for polarization voltage and you just lose like 2db of sensitivity in trade?

[DSatz]

Someone wrote me a private message asking about that, whereupon I went back and re-edited my posting. I had simply assumed the nominal voltage; sorry for any confusion this may have caused.

A modest proposal: Perhaps Mr. Blanc at Sonosax could be asked what voltage his preamp actually puts out. 48 Volts, if that's what it is, would only make the capsules ~1.9 dB less sensitive than the nominal voltage. The exact voltage has no other effect on sound quality as long as it stays constant. And 1.9 dB lower sensitivity wouldn't make an audible difference very often if ever, since the noise floor is so low already. I wouldn't assume that it would necessarily be preferable to have the "Lemosax" provide 60 Volts rather than 48, not knowing the overload point of the preamp's input circuit. One has to look at these things as systems, and not just take one parameter out of context.

For many years Schoeps, Neumann and AKG made 48-Volt phantom-powered microphones with capsules that had originally been designed for 60-Volt polarization, but which were polarized in those models by the incoming 48 Volts without a DC converter, mainly for the sake of a low-current design. This includes the Schoeps CMT 50 series, the AKG C 414 EB-P 48 and almost the entire Neumann fet 80 series including the U 87 and KM 84. Those are still considered to be very good microphones today, so evidently that wasn't such a scandalous thing to do, engineering-wise.

--best regards

[F.O.Bean]

Thanks for the info guys!

[hi and lo]

Since there was a bit of hesitation on this thread a few months ago, I managed to find a post from ts.com that confirms the polarization voltage of the Lemosax is 48v. Original post here:

From Sonosax:

Dear Mr xxxx,

The SX-M2/LS which is no longer available is replaced by the  SX-M2/LS2.

The SX-M2 LS/2 provides with both a 5 pin Binder connector for the Schoeps KCY active cable and two 3 pin Lemo's.
The SX-M2/LS2 supply 48V for the Schoeps capsule.
The voltage difference between the 60V and the 48V is not an issue.
The 12V difference are almost negligible as it affect the max acoustic SPL ( Sound Pressure Level ) accepted at the capsule by only a couples of dB.

I hope this will answer your questions.
Kind regards

Pierre Blanc
SONOSAX
Sales and Customer Support