Long Aux cable run?

texmark

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Oct 24, 2014
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Texas
I need to have my music director on front row with laptop controlling accompaniment track. Need to get that signal to board 80 ft away. Audio is mixed stereo so I need 2 channels. I can use 2 orch pit mic inputs, but how to convert aux out of laptop to that? Help.
 

jkowtko

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Jan 9, 2007
Location
Redwood City, CA
... or use a DI Box. I do this regularly to run DVD projector audio output to my board on the other side of the room.

But yes, for audio playback from a computer, getting a USB I/O interface sounds most appropriate.
 
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DrewE

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Long USB cables can be tricky. Using a USB audio interface to go to a balanced audio run is a perfectly fine idea and stands a good chance of having observably better audio quality than the headphone output of a laptop.

DI boxes work well; connect to a pair of microphone inputs on the mixer.

I have also used a line level unbalanced to balanced converter box much like this. For feeding a line level rather than a microphone input on a mixer, it or an equivalent box is the right tool.
 
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macsound

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Depending on how long the show run is and if it's worth the investment, the headphone jack is a terrible thing to break since it's a small pin, I always try to use USB whenever possible.
 

Ben Stiegler

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Alternatively, analog or USB to Dante "digital DI" can be useful if

- your console can accept Dante directly, or
- in tx/rx pairs if not.

But ... simpler, perhaps ... have you considered putting the laptop at the console position and giving the music director remote control of the laptop, either with freeware like VNC, or with a Bluetooth or IR remote often seen for doing PPT slide advancing? Remote the control, not the audio!
 

Malabaristo

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Wisconsin
I keep a Whirlwind pcDI around for this sort of thing since I'm often using it to connect someone else's device and can't count on being able to add a USB interface. It's passive, stereo or mono with the flip of a switch, has a couple connector options, and is solidly built. Not only is converting to a balanced signal important for the longer distance, but transformer isolation and a ground lift can often cut down on some of the noise you get with mediocre sound cards.

A real audio interface like the Peavey mentioned above is definitely a better choice for overall sound quality if you have the option, but a good DI can make a big difference too.
 

BCAP

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Jan 4, 2017
Location
Ohio
I use a Radial USB Pro. It's a bit more expensive at $229 but here's what I like about it:

1). Adjustable output level on the box. Sometimes this is helpful if I fire off the wrong cue accidentally I can quickly turn down the volume on the box while I get to the right one.
2). Headphones output jack on the box
3). Solid USB driver performance (I have used the Peavey box too and had occasional issues with the USB driver on some computers)
4). Good quality D/A converters 24 bit 96kHz (won't make much of a difference for 16 bit material or MP3 tho..)
5). Mono sum button
6). Ground lift button

Using either a DI box, or a "PC" USB type DI box you may still experience a ground loop between your console and the laptop when running a balanced XLR line, depending on whether there's a difference in AC ground potential. The obvious solution is to use the ground lift button in that case but if you can find a way to run an AC extension cord out to the computer you might be able to solve it that way too.

All of the Radial stuff is built like a brick sh*thouse and more often than not they put excellent components into their gear.
 

DrewE

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Using either a DI box, or a "PC" USB type DI box you may still experience a ground loop between your console and the laptop when running a balanced XLR line, depending on whether there's a difference in AC ground potential. The obvious solution is to use the ground lift button in that case but if you can find a way to run an AC extension cord out to the computer you might be able to solve it that way too.
When was the last time you used a laptop with a grounded (or even polarized) AC power supply? It seems to me it's hard to have a ground loop with no ground line to loop through. Laptop power supplies can be pretty noisy (electrically) in their own right, though, so I don't at all disagree with the several real advantages of using a good outboard DAC of some sort.
 

TimMc

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Feb 15, 2017
When was the last time you used a laptop with a grounded (or even polarized) AC power supply? It seems to me it's hard to have a ground loop with no ground line to loop through. Laptop power supplies can be pretty noisy (electrically) in their own right, though, so I don't at all disagree with the several real advantages of using a good outboard DAC of some sort.
EVERY Dell laptop has a 3 prong AC cord, and many aftermarket laptop replacement PSUs have them, too. They can hum like a mofo.
 
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RonHebbard

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Jun 12, 2004
Location
Waterdown, ON, CA
I use a Radial USB Pro. It's a bit more expensive at $229 but here's what I like about it:

1). Adjustable output level on the box. Sometimes this is helpful if I fire off the wrong cue accidentally I can quickly turn down the volume on the box while I get to the right one.
2). Headphones output jack on the box
3). Solid USB driver performance (I have used the Peavey box too and had occasional issues with the USB driver on some computers)
4). Good quality D/A converters 24 bit 96kHz (won't make much of a difference for 16 bit material or MP3 tho..)
5). Mono sum button
6). Ground lift button

Using either a DI box, or a "PC" USB type DI box you may still experience a ground loop between your console and the laptop when running a balanced XLR line, depending on whether there's a difference in AC ground potential. The obvious solution is to use the ground lift button in that case but if you can find a way to run an AC extension cord out to the computer you might be able to solve it that way too.

All of the Radial stuff is built like a brick excrement house and more often than not they put excellent components into their gear.
Most of us think that way up here North of Donnie's walls. ( Go NANCY!!! You go girl!! )
Toodleoo!
Ron Hebbard
 
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macsound

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Jun 15, 2018
Location
San Francisco, CA
When was the last time you used a laptop with a grounded (or even polarized) AC power supply? It seems to me it's hard to have a ground loop with no ground line to loop through. Laptop power supplies can be pretty noisy (electrically) in their own right, though, so I don't at all disagree with the several real advantages of using a good outboard DAC of some sort.
On some older MacBooks, using the extension to the white brick caused audio noise because it was grounded. So we always used the ducks foot and plugged directly into the outlet.
 

Dan Fischer

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Joined
Nov 6, 2015
Location
Rochester, NY
I need to have my music director on front row with laptop controlling accompaniment track. Need to get that signal to board 80 ft away. Audio is mixed stereo so I need 2 channels. I can use 2 orch pit mic inputs, but how to convert aux out of laptop to that? Help.
we use these over a single cat 5 or cat 6 and they work great. You can also get them in stereo RCA and they are wired pin for pin with the 1/8” so can use 1/8” on one end and stereo RCA on the other if you choose.

 

Daniel Sepke

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Joined
Oct 1, 2018
Location
New York
I'd use the DI route. If you have two DI's on hand you'll need an adapter cable to convert the 1/8" stereo plug to a pair of 1/4" mono.

I have the Switchcraft 702 stereo DI for solving this particular problem as it has 1/4", RCA (phono), and 1/8" inputs and XLR stereo out in a single box. It's a passive DI with Jensen transformers. If stereo isn't an issue you could also use the Switchcraft 718 adapter that takes a stereo 1/8" to a mono XLR with transformer isolation.

Dan