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Stage Snake help - Re. 1/4" returns

Discussion in 'Live Sound [BG]' started by Frankjohnson, Jan 5, 2014.

  1. I have an older 100 ft. whirlwind drop snake I picked up used - and don't use very often. It has 12 XLR sends - all good - no issues.

    It has 3 1/4" TS returns, with two wires to the hot tip connection, foil shielding which is not grounded and a single ground/sleeve.

    I never really used the returns, but was going to last night, and put the monitor amp at the stage, for two sets of monitors. When I tied it into the monitor outs on my carvin powered monitor (not the speaker outs on back - but monitor outs in front) into the QSC GX5 - it hummed really loud (I guess it didn't know the words?). I imagine it did this because the 100 ft run is not balanced.

    It wasn't a problem - I was set up close enough to run speaker cables to the first monitors and chain them. Lucky I wasn't trying to setup farther away - I just wanted to get "out of the way" running sound for a friends band.

    I would like to use the returns If I can without putting too much into it. the 1/4" return setup is ideal for this particular powered head (12 channel - 2 monitor mixes) in the event that I use it this way to get a little more monitor, without having to replace my mixer setup.

    I am not looking to change my "rack" or PA, just the snake so I can use it with my existing equipment. If I convert the TS to TRS on both ends, will that make a difference?

    If its too difficult, I will just use the XLRs as I did last night - and keep the mixer within a decent distance <40 ft from the monitor tie-ins.

    Thoughts, comments, suggestions?
  2. Should do, so long as monitor has balanced inputs.
  3. aleach - I may have to do that - and use adapters. I can't help but wonder why it was made like this???
  4. this one would be perfect for the carvin powered head - just can't deal with that hum. I don't do any large scale sound - but want it to be simple, clean and easy.

    I used this system without the snake for shows with Albert Castiglia, The NightHawks, Chris Duarte, and some others and it was great. The outboard amp for monitors really made it nicer, and the snake would be an improvement on board location too. I can run with it - If I need to - use it for mics only.
  5. jordan2


    Apr 2, 2011
    I couldn't quite tell from reading this but the only thing I can think of was you may have been sending a powered signal through the snake (coming from the output of an amp) and you want it to be unpowered. If that was the case, it may explain the hum but otherwise I don't have any other ideas.
  6. no jordan2 - not powered signal - line level from front of board. when I eliminated the snake, the problem went away. the returns are not balanced and I think that had everything to do with the noise.

    I want to find a way to make it usable - if i can - if not - I will just bypass that option.

    This Head - http://www.carvinguitars.com/products/RX1200L

    Not a great pic - but.....
  7. Ewo

    Ewo a/k/a Steve Cooper Supporting Member

    Apr 2, 2008
    Huntington WV
    If the monitor out of the mixer is unbalanced, a 100 foot run is likely to pick up noise, yeah.

    My buddy at a music store taught me a good trick. Using a short patch cord run the 1/4" unbalanced mixer output into a passive direct box, then send the (now) balanced signal on its way to wherever.

    Added: I've used the ART passive DI this way to convert a line level unbalanced signal to a balanced line level signal. It's got a pad for the unbalanced input, if the signal is too hot for wherever you're feeding it, and a ground lift for the balanced output.
  8. Ewo - thanks - I like that as a possible solution.
    I just saw a rack mounted DI unit - I think it had 4 DI channels in it?

    I hate losing those 3 channels on the snake - but they are gone if I can't use them anyway.
  9. BTW Ewo -
    My old frontman/guitar guy lives in Hunington -

    GREAT blues guy - and my best friend!
  10. Ewo

    Ewo a/k/a Steve Cooper Supporting Member

    Apr 2, 2008
    Huntington WV
    Small world!
  11. Dave Curran

    Dave Curran Lilduke

    Jul 27, 2013
    If there is a twisted pair of wires, with a foil shield, just replace the 1/4 TS with 1/4 TRS, Tip = Hot, Ring = Neg, Sleeve = Grounding shield. Sounds like yours are ground and Neg going to the sleeve.
  12. 4Mal

    4Mal Supporting Member

    Jun 2, 2002
    Columbia River Gorge
    First out of the gate I would check the snake wiring and see if there are enough conductors. Just swapping the ends for trs as noted above could do the trick. If not, I would skip it and build a couple of 100 foot trs/xlr mic cables, zip tie them to the snake and call it good.

  13. You might pick up some noise with a long unbalanced run, but it shouldn’t be at the level you’re talking about – so bad that the line is unusable. I’ve run unbalanced lines well over 100 ft. before, with no ill effect. I’d say more than likely there’s something wrong with the return lines themselves, but it would be unusual that all three of them would be whacked.

    Sure, swapping out the end plugs and jacks for TRS would be a step in the right direction. From your description of the wiring in the TS plug, it sounds like the wiring is in place to accommodate that. However, if the lines themselves have problems, it won’t help. And naturally, your mixer will have to have balanced monitor sends to realize the full advantage of converting the snake to TRS.

    The foil shield itself gets no connection to a plug or jack; there should be what’s called a “drain wire” that makes the shield connection to the plug. Basically, it’s a small bare wire (i.e. no insulation on it). If there is presently no wire at all on the sleeve connection of the plugs, that may well be the source of your noise problem. IOW, you have no shield connection. Not to mention, unbalanced signals use the shield connection for signal (-). So, no shield connection means no signal the amps on stage.

    If there is no drain wire apparent, that doesn’t mean there isn’t one. Just strip back the insulation a bit to find it.

    I’d also check each conductor of each of the sends for end-to-end continuity and shorts with a VOM meter when you do the TRS conversion. If you get continuity between the black and white wires (or whatever color they are), you have a short. Same thing if you get continuity between either of them and the drain wire.

    Hope this helps.

    Wayne A. Pflughaupt

    Administrator, Pedulla Club #45
    Administrator, Tobias Club
    Big Cabs Club #23
    My Rig: Stage and FOH Friendly

  14. I spoke with Al at Whirlwind - he was REALLY helpful -
    The snake was manufactured with unbalanced return connectors, and uses same wire as the Balanced ones.

    I was reading this post as I was on the phone and Al mentioned the drain line. He advised me on installing new TRS plug and jack for each of the returns, and that it should solve the issue. he said this snake is at least 30 years old - and seemed pleased that it is still in service.

    thanks for all the feedback guys -
  15. Ewo

    Ewo a/k/a Steve Cooper Supporting Member

    Apr 2, 2008
    Huntington WV
    Modding the snake will fix the snake--but if your mixer's output is unbalanced, the line will be unbalanced, still. AFAIK.
  16. +1 Yep.
  17. Had called Carvin earlier today - they state that the outputs on the front are balanced - if this is accurate - it should all mesh. and this would all work out just right for the way I use this rig.

    a couple of good pieces of input here for me - thanks guys.