Martin Rush 2 LED parcans/Congo Jr console.

Hi everybody, I'm looking for some advice on the following: Recently purchased a number of Martin Rush 2 LED parcans, connected to an ETC Congo Jr console. Dimmer curves for the Rushes look 'clunky' - I've tried all the different options for this on the lamps, is there any way this can operate more smoothly? I'm new to DMX lights - thanks in advance!

  • Hi Gary,
    What mode are you operating the lamps in? Are you sure that you have the same mode patched?
    The fixture has two different modes. One mode (5 channels) uses the console control of the RGBW to dim. The other uses the on board 16 bit dimming to control the intensity (9 channels). I would recommend using the 9 channel version. You may have to re-address the fixtures if you started with the 5 channel version of the profile.
    LED fixtures and dimming in the low part of the intensity range is always a little tough.
    What version of software are you using on the Congo Jr? Cobalt has profiles for both the 5 channel and 9 channel version.
    Good luck,
  • Hi John, thanks for your reply. We’re operating all lamps in 9 channel mode. I’m not sure what you mean by ‘on board 16 bit dimming to control the intensity’, is this referring to the lamp itself? I've set the fade curve to mode 4 to see if that helps.

    Firmware version for all lamps is A: 1.5, Ab: 1.0 (not sure what the Ab refers to).
Reply Children
  • Make sure you've updated your console to the latest Cobalt software - currently 7.3.1.
    There have been various improvements to 16-bit Intensity over the years.

    However, LEDs aren't tungsten and don't behave the same.

    An LED can snap to a different level instantly, while tungsten always fades due to the physics of a filament.
    In a mixed rig this difference can be quite visible.

    Some LED fixtures have built-in smoothing and/or various forms of tungsten simulation, which might be adjustable or can be enabled/disabled.

    I believe the RUSH 2 LED Par has settings for dimming curve and speed/smoothing, you may wish to adjust those.

  • Hi Gary,
    What version of Congo/Cobalt software are you running on the board?
    I would try patching the fixture as 9 individual dimmer channels and see how the fixture responds. If the dimming is clunky, it might be just the way the fixture responds. Especially pay attention to how the fine Intensity responds at low levels and with the course Intensity at low levels.
    The nine channel mode uses the fixture to dim the level. In the five channel mode, the console does a virtual intensity by dimming all of the colors. The nine channel mode of the fixture includes two channels to control intensity. There is a course channel (big changes) and a fine channel (smaller steps within the big changes). Each channel of DMX has 8 bits of data (0-255). When you put two channels together, you get 16bit channels. These are typically used for Pan & Tilt but have become used for intensity of late to give better control of the low end of the dimming range. In this way, the intensity can be adjusted for the levels between 0% & 1% into approximately 650 steps. Congo/Cobalt doesn't usually worry about all of the fine DMX steps and increases the fine DMX by 4 bits to reduce the amount of data being crunched.
    I would start with the fixtures in a linear dimmer curve. I would experiment with other curves once I have a good baseline. I would be inclined to use mode 2.
    Also, check that the on the fixture the dimming speed is set to "FADE" for smoother fades.
    Hope this helps.
  • Hi John and Richard. Not sure what I've done but it seems a bit better now. Thanks!