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Rear Mic Input Wiring

AE0MW Member ✭✭
edited November 2019 in FLEX-6000 Signature Series
This really seems like something I should know, but I've never really been involved with commercial or "prosumer" audio gear so I'm not sure and could use some pointers.

Due to some long overdue shack reconfiguration, I need to the move my microphone connection from the 8-pin front jack to the rear of my 6500.

The hardware reference document says that the rear balanced input is suitable for a dynamic microphone, but stops short of a recommendation on the best way to wire it.

What is the best way to connect a conventional dynamic microphone to the rear inputs?

My thought is that I should wire the tip and ring of a TRS connector to the MIC+ and MIC- and then PTT to the RCA jack.

Is there any advantage/disadvantage to this over using the XLR connector?

Currently I'm setup for the 8pin front jack, but I can make adjustments if necessary. I am feeding audio into the 6500 from a NCS-3240 so I have a fair bit of flexibility regarding drive levels, etc.

Thanks in advance!

-Mike AE0MW


  • VE2MBT
    VE2MBT Member
    edited November 2019


    I have a Heil PR-781 directly hooked to the rear XLR plug, i then use a Heil foot switch to PTT the radio AND the amp.

  • Barry N1EU
    Barry N1EU Member ✭✭
    edited February 2017
    TRS and XLR are equivalent.  Here's a good treatment of how to connect an unbalanced mic to balanced input and the pitfalls:  https://www.presonus.com/news/articles/balanced-unbalanced

    Personally, I'd consider springing for a decent mic using XLR balanced connector and take full advantage of the common mode rejection of the 6500 balanced mic input.

    73, Barry N1EU
  • AE0MW
    AE0MW Member ✭✭
    edited January 2017
    Marc, I expected that but thanks for the verification!

    Barry, thank you for the excellent article. I quickly skimmed it but will read it more thoroughly later. It looks like the primer I need on audio. A quick skim makes me think of balanced audio more like RS-422 differential serial port wiring.

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