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I'm looking at a situation where I'd want to connect a number of devices together to pass line level analog audio signals around. For the connections in question, there will always be small groups of channels (I've been assuming groups of 4) that go together. So rather than require a big mess of patch cables, I'm wondering what existing off the shelf items would work. 1m Cat-5/6 patch cords are easy to get and would have the correct number of conductors and meets the mechanical requirements but how would it do for signal quality?


Edit 1: I'm not sure that I didn't introduce some confusion here. I haven't settled on what kind of signaling I'm going to be using other than that it doesn't inherently need to deliver any power (the component at the other end will have whatever amps are needed to avoid that).

Edit 2: In the case I'm considering, I would be building the devices at each end and one of the advantages I'm seeing to using Cat5 is that I can use a single RJ-45 jack rather than four 1/4in TRS or XLR jacks (one of the devices could easily be limited by panel space for jacks).

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    \$\begingroup\$ It would work well, or at least for your back pocket: amazon.com/Denon-AKDL1-Dedicated-Link-Cable/dp/B000I1X6PM/… \$\endgroup\$
    – Thomas O
    Oct 11, 2010 at 16:53
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    \$\begingroup\$ Look at the price tag. $999.99. \$\endgroup\$
    – Thomas O
    Oct 11, 2010 at 17:04
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    \$\begingroup\$ An audiophool is born every minute. \$\endgroup\$
    – Thomas O
    Oct 11, 2010 at 17:26
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    \$\begingroup\$ $999.99? Dang, it went up - used to be $500. Times are tough. \$\endgroup\$
    – J. Polfer
    Oct 11, 2010 at 17:33
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    \$\begingroup\$ That is the refurb price. The new price is $9,999 \$\endgroup\$
    – Kellenjb
    Oct 11, 2010 at 18:39

3 Answers 3

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Should be fine over short distances. If the cable is going to be in a noisy environment (lots of 50/60hz EM especially) go with shielded CAT5 and make sure the shield is grounded properly.

If your looking at longer distances, consider differential signaling, which again the twisted pairs of a cat5 cable are just fine for.

As always when dealing with patching devices together like this be careful of creating ground loops.

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    \$\begingroup\$ I agree. I think cat5 will get the job done, shielding cannot hurt, only connect it on one side. \$\endgroup\$
    – Kortuk
    Oct 11, 2010 at 16:50
  • \$\begingroup\$ Luckily, STP is a standard item. \$\endgroup\$
    – BCS
    Oct 11, 2010 at 16:51
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    \$\begingroup\$ @Kortuk: That's an interesting thought, I wonder if a ground disconnect switch at each jack would be a good idea? \$\endgroup\$
    – BCS
    Oct 11, 2010 at 16:53
  • \$\begingroup\$ A switch on the aux device is typically what I have seen, but not one at the main device. \$\endgroup\$
    – Kellenjb
    Oct 11, 2010 at 17:03
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    \$\begingroup\$ You want to ground the shield on the sending end of the link normally when its a 1 way link. You may want to plan ahead for ground loops if you know up front the various devices have very different ground potentials (separate virtual grounds). However, if your inputs are isolated well you should be fine. Normally on an audio input i'll use an opamp in a differential configuration even if the incoming signal isn't differential. This keeps the input ground from ever touching the device's ground. \$\endgroup\$
    – Mark
    Oct 11, 2010 at 17:08
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From what I've seen in radio stations, they work well.

The audio is differential and the twisted pair removes common mode noise.

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    \$\begingroup\$ So it's actually used by people who know what they are doing? \$\endgroup\$
    – BCS
    Oct 11, 2010 at 16:55
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    \$\begingroup\$ I would think radio stations would use balanced xlr everywhere. If they are using CAT5 it is probably because it got converted to digital. \$\endgroup\$
    – Kellenjb
    Oct 11, 2010 at 17:06
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    \$\begingroup\$ They are running analog audio over the CAT5. It's cheaper, available, and works. The only difference between CAT5 and Balanced XLR are the connectors and the shield. \$\endgroup\$ Oct 11, 2010 at 17:12
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    \$\begingroup\$ Choose balanced and differential for long lines. \$\endgroup\$
    – endolith
    Oct 12, 2010 at 1:34
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    \$\begingroup\$ @endolith: How long is long? I'm not expecting anything longer than a meter, two at the outside. \$\endgroup\$
    – BCS
    Oct 12, 2010 at 14:49
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I have found that the gauge of cat5 seems to be too small of diameter for line level audio. It may work just fine but you might want to consider something like this: http://www.parts-express.com/pe/showdetl.cfm?Partnumber=240-286

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  • \$\begingroup\$ Cat5 comes in many gages. What size is needed for line level stuff? It's not like I'll be driving any power through it. The kind of patch cord used to connect computer speakers to sounds cards can't be much bigger. \$\endgroup\$
    – BCS
    Oct 11, 2010 at 20:40
  • \$\begingroup\$ Also, one of the reason I'm looking for a multi channel cable it to reduce the real estate the jacks take up. \$\endgroup\$
    – BCS
    Oct 11, 2010 at 20:46
  • \$\begingroup\$ I was confused as to what you were asking. I was under the assumption you had prebuilt equipment and were going to solder connectors to the CAT5. In the case where you are soldering connectors on, since the wire is so small, it tends to break off easily when getting beat around like many connectors do. \$\endgroup\$
    – Kellenjb
    Oct 12, 2010 at 0:41
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    \$\begingroup\$ If you are building both ends yourself then I think you can easily get away with CAT5 cable. If you are worried about noise you can create a differential signal to put on the lines. (Example: sound.westhost.com/project51.htm) \$\endgroup\$
    – Kellenjb
    Oct 12, 2010 at 0:48

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