the kid Posted February 14, 2011 Share Posted February 14, 2011 Just wondering, I am plannning this week to run some mic's in to my main PA desk (in theatre) then run out (mono) of that in to a snake in to another desk(media) (through c4) Logicaly I cannot see any issues, However media are using some mics that require +48 and the desk is non selective. Is this likley to cause issue with my desk? I have never done anything like this before, and logically I cannot see any problems, but you never know. Thanks Tom Link to comment Share on other sites More sharing options...
themadhippy Posted February 14, 2011 Share Posted February 14, 2011 Id put a transformer/di box in there,some desk outputs dont like having 48v shoved up em, Link to comment Share on other sites More sharing options...
Ynot Posted February 14, 2011 Share Posted February 14, 2011 Id put a transformer/di box in there,some desk outputs dont like having 48v shoved up em,Not sure why... If the mics are fed into a desk with phantom power, then the 48v is going out towards the mic heads as needed.If the OP then feeds a mono output to another desk into a normal line-in input, then there's absolutely no way that the second desk is going to see that voltage.We do this all the time - piggy backing one desk into another as a sub-mix. Unless I've misunderstood the OP's problem... Link to comment Share on other sites More sharing options...
stevefez Posted February 14, 2011 Share Posted February 14, 2011 Id put a transformer/di box in there,some desk outputs dont like having 48v shoved up em,Not sure why... If the mics are fed into a desk with phantom power, then the 48v is going out towards the mic heads as needed.If the OP then feeds a mono output to another desk into a normal line-in input, then there's absolutely no way that the second desk is going to see that voltage.We do this all the time - piggy backing one desk into another as a sub-mix. Unless I've misunderstood the OP's problem...I read it that the SECOND desk was using phantom, so would send 48v up the output of the first desk. But I might be wrong. Link to comment Share on other sites More sharing options...
themadhippy Posted February 14, 2011 Share Posted February 14, 2011 ive read it that the main desk is feeding into the media desk,the media desk is supplying global phantom to all input channels,hence 48v going back to the main desk Link to comment Share on other sites More sharing options...
andy_s Posted February 14, 2011 Share Posted February 14, 2011 if your mics also require phantom, would it be simpler to use a splitter to send the mics to both desks, and use the non-selective desk to provide the power. Or do you want to do things to the mics on your desk before sending them to the second desk? E4spelling Link to comment Share on other sites More sharing options...
Shez Posted February 14, 2011 Share Posted February 14, 2011 As long as you're plugging in to a line input as opposed to a mic input, it matters not where phantom is switched on or off. Of course, if the desk only has XLR inputs and no jacks for line inputs, then it may be more of an issue. Tom, could you clarify what inputs are available on the desk to whose input you want to connect the output of another desk? Link to comment Share on other sites More sharing options...
Wilflet Posted February 14, 2011 Share Posted February 14, 2011 Id put a transformer/di box in there,some desk outputs dont like having 48v shoved up em,Not sure why... If the mics are fed into a desk with phantom power, then the 48v is going out towards the mic heads as needed.If the OP then feeds a mono output to another desk into a normal line-in input, then there's absolutely no way that the second desk is going to see that voltage.We do this all the time - piggy backing one desk into another as a sub-mix. Unless I've misunderstood the OP's problem...I read it that the SECOND desk was using phantom, so would send 48v up the output of the first desk. But I might be wrong. Thats how I read it too, does the media desk have any line inputs/2 track/anything none mic input? Link to comment Share on other sites More sharing options...
Doug Siddons Posted February 14, 2011 Share Posted February 14, 2011 FWIW thursday taking a balanced main output from a subdesk desk into mine as main FOH desk, with phantom switched on mine, caused major problem until phantom switched off on those channels. Link to comment Share on other sites More sharing options...
sleah Posted February 14, 2011 Share Posted February 14, 2011 If the desk being fed INTO has only Mic inputs available (because it's being fed by the snake? :huh: ), could the output from the first desk not simply be DI'd in to the second desk? (well, in to the snake...)Surely a DI wouldn't pass phantom to it's input? :blink: Link to comment Share on other sites More sharing options...
the kid Posted February 14, 2011 Author Share Posted February 14, 2011 (my side)3 mics all running +48 mixed to mono and out to media desk (all XLR (HOWEVER it could be jack>XLR out)) (Media side) 2 mics running +48 AND input from my desk (all XLR in) Link to comment Share on other sites More sharing options...
Simon Lewis Posted February 14, 2011 Share Posted February 14, 2011 This is an increasing problem as we move to digital desks with wide ranging mic preamps offering only XLR connectors (although of course many analogue desks were XLR only).Device outputs can very easily be hit with 48V if phantom is left on. Some devices may have a dc blocking capacitor on the output, but not all do, and there have been cases reported on BR in the past day or so of media devices being fried when connected this way.I would use a pair of DIs to make sure that protection is ensured! Simon Link to comment Share on other sites More sharing options...
the kid Posted February 14, 2011 Author Share Posted February 14, 2011 So with the Di, I assume Use the jack out and then run down to media. Link to comment Share on other sites More sharing options...
ceecrb1 Posted February 14, 2011 Share Posted February 14, 2011 ok this is something I do far more than micing up bands.... linking up to events with our OB truck and I myself send many feeds to ob trucks etc. So lets say you send AUX 1 from your desk to the media desk.. It could be XLR or Jack outs, depending on your desk.. you will know which.use either an XLR- Jack or Jack-Jack to enter the DI box from the AUX 1 of your desk.From the DI box, output XLR and run that to the media desk to an XLR input with phantom power.The media desk will power the DI box and insulate your desk from phantom power, it will also reduce the line level output from your desk to mic level so it will enter the media desk at a more manageable level. This is one way. Another (more simple) way, if available would be, jack or XLR out from AUX 1, convert to balanced XLR.. run your cable.... convert back to JACK and enter a LINE IN in the media desk.. At all stages balanced connectors and cables should be used to keep the entire system balanced and less prone to picking up noise on the way. Not got the converters... get a soldering iron out and make them up. p.s what desks are you using?You say media desk is XLR only.. well so is my LS9 and that can be line or mic level, and phantom on individual channels... others might just be mic only and phantom on all or none...also what is your desk... this way we can SEE what you need and give you the best advice for your setup. Link to comment Share on other sites More sharing options...
dwright2104 Posted February 14, 2011 Share Posted February 14, 2011 get one of theseBSS Ar133, it has XLR in and out, simply connect XLR out of 1st desk to the in on DI box, then out DI box into 2nd desk with phantom power, no problems. Keep the XLR from 1st desk to DI box short as poss as the signal will be unbalanced. ps I have never used a desk that likes phantom power in its outputs. the LS9 is a desk that absolute hates it, it will safty cut all output ports on desk, required the desk to be rebooted. Link to comment Share on other sites More sharing options...
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