technz
so, i have a small 6 channel mixing desk that i run all my audio through, DJ gear and PC.
in the past i have used phantom power for a couple of shotgun mics for an event i was doing.
however im always scared that ill accidentaly flip on phantom power while i have my Traktor Kontrol S4 hooked up via Balanced TRS - XLR cables.
i have a moderate understanding of electricity and electronics, but im slightly in the dark when it comes to the audio side of it.
so my question is as follows.
how does phantom power work?
and
can it damage my controller?
in the past i have used phantom power for a couple of shotgun mics for an event i was doing.
however im always scared that ill accidentaly flip on phantom power while i have my Traktor Kontrol S4 hooked up via Balanced TRS - XLR cables.
i have a moderate understanding of electricity and electronics, but im slightly in the dark when it comes to the audio side of it.
so my question is as follows.
how does phantom power work?
and
can it damage my controller?
Posté Sun 06 Jan 13 @ 11:05 pm
Dazmax
Hi mate :-)
Phantom power is a DC supply that is connected equaly to both the hot and cold legs of a balanced line cable. It is referenced (Or has its return path) vea the shield conductor in the Balanced Line cable. As balanced lines work by looking at the difference signal between the hot and cold legs the DC voltage is not seen by microphone coils and other equipment. The power supply is limited to a Max of 48V dc and a current around 2mA. There should not be any issues hooking up your Tractor unit but if you want to be 100% sure. Make yourself a pair of cables TRS to XLR and isolate the shield conductor at one end to break the return path for the Phantom Power. The Shield conductor is the braided or uninsulated wrap that covers the two Hot and Cold insulated conductors.
Pin 1 on the XLR or the Sleeve conductor on a Jack. The screen will still function as it is, just that, a shield. It takes no part in the audio signal that passed through the cable. Connecting at one end only is perfectly ok and will not affect performance.
Cheers
Daz
Phantom power is a DC supply that is connected equaly to both the hot and cold legs of a balanced line cable. It is referenced (Or has its return path) vea the shield conductor in the Balanced Line cable. As balanced lines work by looking at the difference signal between the hot and cold legs the DC voltage is not seen by microphone coils and other equipment. The power supply is limited to a Max of 48V dc and a current around 2mA. There should not be any issues hooking up your Tractor unit but if you want to be 100% sure. Make yourself a pair of cables TRS to XLR and isolate the shield conductor at one end to break the return path for the Phantom Power. The Shield conductor is the braided or uninsulated wrap that covers the two Hot and Cold insulated conductors.
Pin 1 on the XLR or the Sleeve conductor on a Jack. The screen will still function as it is, just that, a shield. It takes no part in the audio signal that passed through the cable. Connecting at one end only is perfectly ok and will not affect performance.
Cheers
Daz
Posté Mon 07 Jan 13 @ 8:37 am
groovindj
I'd say the best way to avoid zapping your controller with phantom power is to NOT plug it into mic inputs.
You shouldn't be doing this anyway, regardless of phantom power. The outputs of DJ controllers are line level.
The balanced output of the S4 is there for feeding into the balanced input of an amplifier or powered speakers, not a mixing desk mic input.
Instead of feeding the S4 into the mixing desk, why not do it the other way round and feed the mixing desk into an input of the S4?
Use the S4 as the master device (outputs connected to PA). That way you can use phantom power without worrying about killing anything because the S4 will be last in the chain.
You shouldn't be doing this anyway, regardless of phantom power. The outputs of DJ controllers are line level.
The balanced output of the S4 is there for feeding into the balanced input of an amplifier or powered speakers, not a mixing desk mic input.
Instead of feeding the S4 into the mixing desk, why not do it the other way round and feed the mixing desk into an input of the S4?
Use the S4 as the master device (outputs connected to PA). That way you can use phantom power without worrying about killing anything because the S4 will be last in the chain.
Posté Mon 07 Jan 13 @ 10:03 am
Dazmax
Fair point Groovin :-)
Although these days the majority of mixing desk inputs have variable gain input preamps. This allows both Mic and Line level inputs to be used so plugging into them is not realy a problem.
It does make total sense to feed the S4 output direct to the amps if for no other reason than to reduce noise/distortion being added into the signal from the mixing desk. I suppose it depends on wether or not the EQ on the mixing desk channels is being used for some form of master EQing for the S4/VDJ.
Phantom power is designed Not to Zapp the inputs of equipment that do not require it and there is almost no equipment in production these days which is not fitted with coupling capacitors on every input. These block DC from entering the input amp stage and provide a block to Phantom power.
Still the point is well made. It just makes sense to use the S4 as the master out :-)
Daz
Although these days the majority of mixing desk inputs have variable gain input preamps. This allows both Mic and Line level inputs to be used so plugging into them is not realy a problem.
It does make total sense to feed the S4 output direct to the amps if for no other reason than to reduce noise/distortion being added into the signal from the mixing desk. I suppose it depends on wether or not the EQ on the mixing desk channels is being used for some form of master EQing for the S4/VDJ.
Phantom power is designed Not to Zapp the inputs of equipment that do not require it and there is almost no equipment in production these days which is not fitted with coupling capacitors on every input. These block DC from entering the input amp stage and provide a block to Phantom power.
Still the point is well made. It just makes sense to use the S4 as the master out :-)
Daz
Posté Mon 07 Jan 13 @ 12:10 pm
technz
due to the speaker setup i use at home i need to use the mixing desk, however i will go purchase some balanced TRS cables sometime this week, i only used the XLR cables because it was what i already had.
Posté Mon 07 Jan 13 @ 1:38 pm
Dazmax
One other thought on this.
If the PA mixer only has balanced Master Outs this would make hooking it to an input on the S4 a bit of a pain as these inputs would be unbalanced and there could even be level matching issues depending on the sensitivity of the inputs on the S4. Both setups can be made to work but its down to personal preferance as to what you feel happy doing.
Daz
If the PA mixer only has balanced Master Outs this would make hooking it to an input on the S4 a bit of a pain as these inputs would be unbalanced and there could even be level matching issues depending on the sensitivity of the inputs on the S4. Both setups can be made to work but its down to personal preferance as to what you feel happy doing.
Daz
Posté Mon 07 Jan 13 @ 1:39 pm
technz
okay, im about to hijack my own thread here, but its sort of related to the answers ive been getting.
im having trouble finding balanced TRS cables locally, is there any downside to using unbalanced cables over a short run, maybe 1.5 - 2m?
im having trouble finding balanced TRS cables locally, is there any downside to using unbalanced cables over a short run, maybe 1.5 - 2m?
Posté Mon 07 Jan 13 @ 11:03 pm
blckjck
Usually short distances are okay if there is no noisy equipment around. I run unbalanced from my Mixtrack Pro to my Mackie console without issues.
Posté Tue 08 Jan 13 @ 12:34 am
Dazmax
Ok sorry to answer a question with another question but why do you need them?
If you do realy need them then you could order them online. If I read what you have said so far correctly you have been using TRS to XLR cables. Is that correct ?
Perhaps a little more info on your mixer and exactly how you intend to connect it would help :-)
If you have the choice of using balanced cables it is well worth doing. While unbalanced lines are usualy ok for short runs they can introduce other issues ie Ground loops. Check that your mixer will allow Phantom Power to be used with a non TRS Jack. This could cause you problems as using a TS jack will short one leg of the balanced line and could give you an issue withe the Phantom Power appearing across the Sleeve and Tip especialy if the Pahantom Power is applied Globaly ie all inputs at the same time. Exactly what you did not want to do!!!!
Daz
If you do realy need them then you could order them online. If I read what you have said so far correctly you have been using TRS to XLR cables. Is that correct ?
Perhaps a little more info on your mixer and exactly how you intend to connect it would help :-)
If you have the choice of using balanced cables it is well worth doing. While unbalanced lines are usualy ok for short runs they can introduce other issues ie Ground loops. Check that your mixer will allow Phantom Power to be used with a non TRS Jack. This could cause you problems as using a TS jack will short one leg of the balanced line and could give you an issue withe the Phantom Power appearing across the Sleeve and Tip especialy if the Pahantom Power is applied Globaly ie all inputs at the same time. Exactly what you did not want to do!!!!
Daz
Posté Tue 08 Jan 13 @ 2:02 pm
technz
a little bit of info on my setup, the mixer is a LEEM HM624
i use this mixer at home mainly due to my speaker setup. i cant afford to use an expensive sound system for my pc/dj setup.
so instead i use a small set of 2.1 computer speakers and a stereo system with a 3 disc changer (disc changer is irrelevant only used to demonstrate the size of the unit).
by combining these two sets of speakers i end up with near enough to full frequency response.
this is where the mixer comes in handy, by running the larger speakers through the Ctrl room output and the small set through the headphone output, i can balance the two volumes out so things sound right.
phantom power is not required by any of the gear in this setup.
i have enough TRS - RCA adaptors to use RCA cables if need be, however i would rather run cables without adapters.
let me know if you want any more information.
i use this mixer at home mainly due to my speaker setup. i cant afford to use an expensive sound system for my pc/dj setup.
so instead i use a small set of 2.1 computer speakers and a stereo system with a 3 disc changer (disc changer is irrelevant only used to demonstrate the size of the unit).
by combining these two sets of speakers i end up with near enough to full frequency response.
this is where the mixer comes in handy, by running the larger speakers through the Ctrl room output and the small set through the headphone output, i can balance the two volumes out so things sound right.
phantom power is not required by any of the gear in this setup.
i have enough TRS - RCA adaptors to use RCA cables if need be, however i would rather run cables without adapters.
let me know if you want any more information.
Posté Tue 08 Jan 13 @ 3:05 pm
groovindj
I did mention this before, but now I know what mixer you have, I'd suggest running the output of your S4 into the line inputs on channels 3/4 or 5/6 and NOT the mic inputs.
That way you will avoid frying the S4 with phantom power and you should get a better S/N ratio at the output with less chance of distorting the signal.
That way you will avoid frying the S4 with phantom power and you should get a better S/N ratio at the output with less chance of distorting the signal.
Posté Tue 08 Jan 13 @ 3:21 pm
technz
ill go pick up a set on unbalanced TRS cables during my lunch break.
thanks for all the help guys
thanks for all the help guys
Posté Tue 08 Jan 13 @ 7:01 pm
Dazmax
+1 Groovin :-D
Def the way forward.
Daz
Def the way forward.
Daz
Posté Tue 08 Jan 13 @ 9:14 pm