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Neutrik with built-in EMI?

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  • userno232000
    Any comments? I found myself at the last good electronics DIY store in town and picked up a couple for my latest project. Actually not much more than the poor
    Message 1 of 6 , Jan 2, 2009
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      Any comments? I found myself at the last good electronics DIY store in
      town and picked up a couple for my latest project. Actually not much
      more than the poor quality Radio Shack ones. Some of their stereo mini
      jacks have become virtually impossible to assemble without shorting
      left and right channels.
    • userno232000
      ... in ... mini ... I guess I answer my own question. Total elimination of all computer monitor spurs, my OTT-LITE, some CFL s, two TV s, no hum even at 70dB
      Message 2 of 6 , Jan 2, 2009
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        --- In micbuilders@yahoogroups.com, "userno232000" <scott.wurcer@...>
        wrote:
        >
        > Any comments? I found myself at the last good electronics DIY store
        in
        > town and picked up a couple for my latest project. Actually not much
        > more than the poor quality Radio Shack ones. Some of their stereo
        mini
        > jacks have become virtually impossible to assemble without shorting
        > left and right channels.

        I guess I answer my own question. Total elimination of all computer
        monitor spurs, my OTT-LITE, some CFL's, two TV's, no hum even at 70dB
        of gain.
      • Jim G.
        Scott, Interesting. I m usually sceptical about EMI/RFI claims for connectors. Based on your experience, I m going to try some of those. I m currently testing
        Message 3 of 6 , Jan 2, 2009
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          Scott,

          Interesting. I'm usually sceptical about EMI/RFI claims for connectors.
          Based on your experience, I'm going to try some of those.
          I'm currently testing a DIY battery powered mic. pre-amp.
          It's a good opportunity for me to see the difference they might make.

          Here is a Neutrik blurb:

          The EMC-XLR Series is a specifically designed version of the XX series
          to give enhanced RF screening for critical applications in live
          performance and recording where there are particular problems with
          radio transmission or mobile phones. The design guarantees a continuous
          RF shield connection from the cable to the chassis connector housing
          via a circular capacitor around the cable shield. An EMI suppression
          ferrite bead between pin 1 and the cable screen provides a low-pass
          filter for improved RF rejection.

          Cheers.

          Jim G.

          --- In micbuilders@yahoogroups.com, "userno232000" <scott.wurcer@...>
          wrote:
          >
          > --- In micbuilders@yahoogroups.com, "userno232000" <scott.wurcer@>
          > wrote:
          > >
          > > Any comments? I found myself at the last good electronics DIY store
          > in
          > > town and picked up a couple for my latest project. Actually not
          much
          > > more than the poor quality Radio Shack ones. Some of their stereo
          > mini
          > > jacks have become virtually impossible to assemble without shorting
          > > left and right channels.
          >
          > I guess I answer my own question. Total elimination of all computer
          > monitor spurs, my OTT-LITE, some CFL's, two TV's, no hum even at 70dB
          > of gain.
          >
        • rick chinn
          I am part of the AES standards group that helped develop the standard that this connector is intended to address. If you have a piece of gear with a pin-1
          Message 4 of 6 , Jan 3, 2009
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            I am part of the AES standards group that helped develop the standard
            that this connector is intended to address.

            If you have a piece of gear with a pin-1 problem, the connector is a
            possible defense.

            The crux of the Pin-1 problem is the notion that you want the
            shield/pin1 to go directly to chassis, do not pass go, do not collect $200.

            But many pieces of gear are not built this way. Pin 1 goes to the
            chassis thru a trace on the PCB. From an RF standpoint, this is very
            bad, as the trace acts as an antenna to radiate any induced RF noise
            current in the shield all over the circuitry. After all, the trace is
            of finite length, and has some amount of impedance, thus making an antenna.

            If pin 1 goes directly to chassis, preferably the outside of the
            chassis, then skin effect keeps any RF conducted on the outside of
            the chassis, away from the circuitry. It then flows to earth, via
            whatever grounding system is in place.

            With the new connector, a circumferential capacitor that surrounds
            the signal lines acts to connect the shield to the chassis via the
            connector shell. A lossy ferrite acts to decouple the shield from pin
            1 at RF. Thus we have a reasonable compromise: the shield connects to
            chassis for RF, and connects to the circuitry for DC and audio frequencies.

            If the equipment has a pin 1 problem (susceptibility to currents
            flowing into pin 1 from the outside world), this may help, especially
            if it is RF currents that are then being demodulated once they are on the PCB.

            It certainly can't hurt.

            I have purchased a few of these connectors, just to get the feel for
            them. The connection between the shield and the shell is a friction
            connection; you spread the shield conductors radially around a fiddly
            2-piece conical shield that separates the cable entry from where the
            shield connects to shell. When you mate the connector block/conical
            shield assembly to the strain relief, this forces the shield
            conductors into contact with the conical shield.

            They're a bit fiddly to put on, although I suspect that like many
            other things, practice makes perfect. I've only put four of these
            onto cable, and that cable had opposing Reusen spiral shields (making
            it a bit easier to fan out radially).

            Jim Brown, also part of the standards committee, delivered at least
            one AES paper devoted to the benefits of this connector. His paper is
            heavy on science, and smoke and mirrors is non-existent. Recommended reading.

            John Windt delivered an AES paper that describes the pin-1 problem
            and how to detect it. Also recommended reading.

            If you need more about the pin-1 problem, search the AES papers for
            Neil Muncy.

            Pin 1 problems apply as much to microphones as they do to microphone preamps.

            --rick chinn
          • Jim G.
            Thanks Rick. Here is a nice illustration of the pin 1 problem http://tinyurl.com/3vv5zh Jim G. ... standard ... a ... collect $200. ... very ... noise ... is
            Message 5 of 6 , Jan 3, 2009
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              Thanks Rick.

              Here is a nice illustration of the "pin 1 problem"

              http://tinyurl.com/3vv5zh

              Jim G.

              -- In micbuilders@yahoogroups.com, rick chinn <rickc@...> wrote:
              >
              > I am part of the AES standards group that helped develop the
              standard
              > that this connector is intended to address.
              >
              > If you have a piece of gear with a pin-1 problem, the connector is
              a
              > possible defense.
              >
              > The crux of the Pin-1 problem is the notion that you want the
              > shield/pin1 to go directly to chassis, do not pass go, do not
              collect $200.
              >
              > But many pieces of gear are not built this way. Pin 1 goes to the
              > chassis thru a trace on the PCB. From an RF standpoint, this is
              very
              > bad, as the trace acts as an antenna to radiate any induced RF
              noise
              > current in the shield all over the circuitry. After all, the trace
              is
              > of finite length, and has some amount of impedance, thus making an
              antenna.
              >
              > If pin 1 goes directly to chassis, preferably the outside of the
              > chassis, then skin effect keeps any RF conducted on the outside of
              > the chassis, away from the circuitry. It then flows to earth, via
              > whatever grounding system is in place.
              >
              > With the new connector, a circumferential capacitor that surrounds
              > the signal lines acts to connect the shield to the chassis via the
              > connector shell. A lossy ferrite acts to decouple the shield from
              pin
              > 1 at RF. Thus we have a reasonable compromise: the shield connects
              to
              > chassis for RF, and connects to the circuitry for DC and audio
              frequencies.
              >
              > If the equipment has a pin 1 problem (susceptibility to currents
              > flowing into pin 1 from the outside world), this may help,
              especially
              > if it is RF currents that are then being demodulated once they are
              on the PCB.
              >
              > It certainly can't hurt.
              >
              > I have purchased a few of these connectors, just to get the feel
              for
              > them. The connection between the shield and the shell is a friction
              > connection; you spread the shield conductors radially around a
              fiddly
              > 2-piece conical shield that separates the cable entry from where
              the
              > shield connects to shell. When you mate the connector block/conical
              > shield assembly to the strain relief, this forces the shield
              > conductors into contact with the conical shield.
              >
              > They're a bit fiddly to put on, although I suspect that like many
              > other things, practice makes perfect. I've only put four of these
              > onto cable, and that cable had opposing Reusen spiral shields
              (making
              > it a bit easier to fan out radially).
              >
              > Jim Brown, also part of the standards committee, delivered at least
              > one AES paper devoted to the benefits of this connector. His paper
              is
              > heavy on science, and smoke and mirrors is non-existent.
              Recommended reading.
              >
              > John Windt delivered an AES paper that describes the pin-1 problem
              > and how to detect it. Also recommended reading.
              >
              > If you need more about the pin-1 problem, search the AES papers for
              > Neil Muncy.
              >
              > Pin 1 problems apply as much to microphones as they do to
              microphone preamps.
              >
              > --rick chinn
              >
            • userno232000
              ... (making ... Thanks Rick, great stuff. The problem of WiFi and cell phone interference just keeps getting worse. The .1 mini-cable I was using made this
              Message 6 of 6 , Jan 3, 2009
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                --- In micbuilders@yahoogroups.com, rick chinn <rickc@...> wrote:
                >
                >> They're a bit fiddly to put on, although I suspect that like many
                > other things, practice makes perfect. I've only put four of these
                > onto cable, and that cable had opposing Reusen spiral shields
                (making
                > it a bit easier to fan out radially).
                >
                Thanks Rick, great stuff. The problem of WiFi and cell phone
                interference just keeps getting worse. The .1" mini-cable I was using
                made this very fiddly, but I managed. Unfortunately running the built-
                in battery in my recorder out to my mics defeated it all so I am
                sticking with a small 9V "wart".

                BTW my appologies to anyone who has sent me email, I am off my server
                for the past two weeks.
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