Audio cable tester

The evolution of an XLR / Jack audio cable tester

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As I am working with a lot of XLR audo cables for amateur theater project, I need a simple equipment to test the wiring of my cables.

I am a beginner with electronics and arduino but step by step I hope to make a good cable tester. (It would be good like this usb cable tester: )

XLR Cable Tester v1.2

With two rows of LEDs it can check more problems.

XLR Cable Tester v1.0

It is simple. It works. But it has serious issues.

Standard Tesselated Geometry - 115.02 kB - 04/06/2017 at 19:34


Standard Tesselated Geometry - 54.18 kB - 04/06/2017 at 19:34


Standard Tesselated Geometry - 42.86 kB - 04/06/2017 at 19:34


Standard Tesselated Geometry - 2.52 kB - 04/06/2017 at 19:34


  • Cable Tester v1.2

    borazslo04/13/2017 at 22:25 0 comments

    The Cable Tester v1.0 had some serious issues. That tester could detect non-connected cables/lines but it had problems recognizing miss-connected / switched cables. So I have made a plan for the newer version with the help of @davedarko's comment.

    Check out and test online the new circuit:

    Cable Tester Circuit v1.2

    The new circuit needs a new box as well. But that is for another time.

  • Cable Tester v1.0 (it's so bad)

    borazslo04/06/2017 at 20:27 0 comments

    The very fist version of the cable tester is very simple: four switches with four LEDs. When the cable connected you can switch on/off the buttons and the LEDs bright up if the line has connection. That seems simple and perfect. But ...


    3d Printed Box:

    And the final and working product:

    So it works just fine. When I connect the XLR cable I can check to connectivity of the 3 main lines/pins and the chassis ground.

    Mismatched cables

    But what does this circuit do when some cables are connected but in a wrong way? Sometimes it works just fine (left picture), but in other cases it makes false OK signs (right picture). So it is time to make a better version of the circuit.

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jaymz20au wrote 09/10/2019 at 02:19 point

Hey man, can you update the links now that is gone?

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davedarko wrote 04/06/2017 at 21:03 point

I was wondering why my cable tester got the recent like, now I know :) Good luck with your project, they're the best if you actually want to use them! 

A tip, use LEDs on both sides of the wire, this way you can see where you start and where it comes out - if there is any shorting you'll see more than one LED on one side glowing ;)

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borazslo wrote 04/07/2017 at 07:25 point

Thanks for the advice. Yesterday when I was in the shower I have began to think about something similar. Thank you for the confirmation.

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