Lectro servo/non-servo question

[johnpaul215]

i read the threads about the issues of certain mics used with SM + SMa
xmitters. I'm looking for some feedback before i buy some new
hardware.
My lavs are: TR-50, COS-11x and B6. I had some issues with the TR-50.
As they wear out, I will probably replace them with some version of
the COS-11. I like the flexibility of the B6 as well, so i intend to
keep using those at times.
Right now i own a few LM transmitters (not LMa). I'm planning on
buying SMa and/or MM400c transmitters.
Am i going to have to make adapters, or keep two sets of mics, because
i would have LM and SMa transmitters? It sounds like the COS-11 and B6
are the big culprits, and those are the lavs i want to use.

[Rob Lewis]

If you go to Lectro and download the Servo Bias Input wiring info PDF,
there are two different wiring configs for servo bias and non servo
bias input transmitters. My recommendation (and it is just mine) is
that you use the universal wiring (works with servo and older
transmitters). This will give you the most flexibility.

Now for my experience: Previously owned the um200 transmitters now
have um400a's

(Note: Servo only wiring does make most mics fairly hot at the input.)

For the COS-11x: I use the universal wiring with my um400a's. Good
hot level at the transmitter and clean. I liked the universal for the
200's as well to keep the compander noise down on quieter subjects.
easy to wire either way.

For the B6: Using the universal wiring will also work well and be
flexible, but they are a bit noisier when used with the servo inputs.
I rewired mine for servo only and they are much quieter, but keep in
mind that I am all um400a transmitters. If you are using 411/401 RX
units than you may just want to set the noise reduction to full when
using the B6's. PITA to wire for universal, but easy to wire for
servo.

There is a post here and on the Lectro FQA about the servo and
universal wiring differences. Larry Fisher describes the noise
difference between the two and the reason why.

http://groups.google.com/group/rec.arts.movies.production.sound/browse_thread/thread/afd86c5ca5685ac8/3fe13edda0d757e3?lnk=gst&q=b6+*+sm#3fe13edda0d757e3

This has been my experience with my transition from 200 systems to an
all Digital bag with servo transmitters. I'm sure others will chime
in with other opinions, but it is a start.

P.S. I'm very picky about how noisy my lavs are so I went with the
optimum setup for my transmitters. The only compromise i have found
is with the B6.

Rob

[Larry Fisher]

Hi John,
Simply wire the mics according to the compatible wiring specs on our
web site and there will be no need for adapters between the LM and SMa
transmitters.
http://www.lectrosonics.com/service/ServoBiasWiring.pdf

See fig. 1 for the B6's and Fig. 5 for the COS-11's
Best Regards,
Larry Fisher
Lectrosonics



On Fri, 26 Dec 2008 10:49:38 -0800 (PST), johnpaul215

Post by johnpaul215
i read the threads about the issues of certain mics used with SM + SMa
xmitters. I'm looking for some feedback before i buy some new
hardware.
My lavs are: TR-50, COS-11x and B6. I had some issues with the TR-50.
As they wear out, I will probably replace them with some version of
the COS-11. I like the flexibility of the B6 as well, so i intend to
keep using those at times.
Right now i own a few LM transmitters (not LMa). I'm planning on
buying SMa and/or MM400c transmitters.
Am i going to have to make adapters, or keep two sets of mics, because
i would have LM and SMa transmitters? It sounds like the COS-11 and B6
are the big culprits, and those are the lavs i want to use.