Making Cables - Balanced vs Unbalanced

[Nosirrom]

I am planning on making some of my own cables soon and was wondering if I should even worry about making any Unbalanced cables. The price difference is very minimal (allmost seems cheaper to make all balanced cables). as well as the fact of ordering two different types of Cable.

Is there any reason to use unbalanced cables? From what I have read balanced cables are rendered unbalanced when run through an unbalanced signal, are there any drawbacks in using strictly balanced cables for everything (Guitar/Amps/Ect)?

Thanks

 

[bennychico11]

there is no such thing as balanced and unbalanced cables.
only a balanced and unbalanced signal.


purchase 2 conductor, shielded (preferably braided) instrument cable. For XLRs and TRS cables use one lead for positive (typically Tip and pin 2), the other lead for negative (ring and pin 3) and then unbraid part of the shield and tie it to ground (sleeve and pin 1). These cables you can use for typical balanced signals.

for unbalanced signals you can still use the 2 conductor cable and omit the shield and use one conductor for hot and the other for ground.

for cables the odd connections (ie. RCA to XLR)...Positive to tip, ground to sleeve and then tie negative to ground as well.

 

[Nosirrom]

there is no such thing as balanced and unbalanced cables.
only a balanced and unbalanced signal.


purchase 2 conductor, shielded (preferably braided) instrument cable. For XLRs and TRS cables use one lead for positive (typically Tip and pin 2), the other lead for negative (ring and pin 3) and then unbraid part of the shield and tie it to ground (sleeve and pin 1). These cables you can use for typical balanced signals.

for unbalanced signals you can still use the 2 conductor cable and omit the shield and use one conductor for hot and the other for ground.

for cables the odd connections (ie. RCA to XLR)...Positive to tip, ground to sleeve and then tie negative to ground as well.

Perhaps my termonology was incorrect but that is what I ment "signal". I've done my research on the actual process of creating balanced and unbalanced signals and how to wire each accoringly.

My main question was "why" would/should I use a unbalanced signal?

 

[mixsit]

...for unbalanced signals you can still use the 2 conductor cable and omit the shield and use one conductor for hot and the other for ground.

But skip the shield?

 

[bennychico11]

But skip the shield?

that's what I do. So the shield acts just as a shield should...still protecting from RFI. Ground is still tied to ground and you still have hot.
or now that I think about it, I guess there have been times I use the shield as the ground and tie the other two to hot...but I hate trying to solder two wires onto one lead and hoping that one doesn't become disconnected over time and short to something else. But I also hate using quad cable. Although some prefer to have two on one lead for better reliability of connectivity...I don't know. I don't think it really matters which conductors are soldered to which lead as long as they match on both ends of the cable.

of course I'm no EE...so maybe someone might come along and say soldering the shield to ground is better for passing the RMI on to ground instead.

My main question was "why" would/should I use a unbalanced signal?

with short connections it's usually no big deal. 'Unbalanced' is generally just cheaper and easier to make. I say stick with the two conductor cable and make yourself XLR or TRS cables.

 

[Nosirrom]

I say stick with the two conductor cable and make yourself XLR or TRS cables.

That what I was looking for, this was my orginal plan but I wanted to know any drawbacks, a second opinion helps.

 

[robin watson]

I agree that for home studio purposes, unbalanced is usually fine (and certain people even argue it is sonically superior), and using XLRs in unbalanced configuration is fine, since it's the connector type itself that dictates, but there is NO point in using TRS connectors in unbalanced config, since a TS cable will do the job a bit cheaper, will be easier to solder (marginally) and will never be mistaken for a balanced cable.

Also, it's perfectly standard practice to call a cable "balanced" or "unbalanced." Next, he'll be saying there's no difference between a B/W TV and a Colour TV, only the type of broadcast it receives.

Whoops, I misunderstood perhaps - he is describing a 'balanced' connection for TRS - XLR, excuse me.

 

[brendandwyer]

i have found that if you are using a patchbay and 2 conductor cabling for it, the chances of picking up RFI is high. My setup a few years back mistakingly used 2 conductor cables and an unbal PB and there was so much noise it was ridiculous.

Then i started building cables, understanding the different signals, and rewired the whole place.

now it's silent.

 

[bennychico11]

Also, it's perfectly standard practice to call a cable "balanced" or "unbalanced." Next, he'll be saying there's no difference between a B/W TV and a Colour TV, only the type of broadcast it receives.

not quite. but I will say there is no such thing as a B/W or Color composite video cable.
A cable doesn't care what kind of signal is passed through it. For example, a TRS connector/cable can be used for balanced signals....and it can be used for a stereo signal (unbalanced). Heck you can send an unbalanced signal down a TRS cable. The type of connector or cable used does NOT make a signal balanced. It's the gear on the ends of the cable that does

 

[altitude909]

That what I was looking for, this was my orginal plan but I wanted to know any drawbacks, a second opinion helps.

Using a balanced cable when plugging a non balanced device into a balanced device results in a loss of 6 db since there will be nothing connected to one wire

 

[tvolhein]

Use for unbalanced

I have an acoustic bass that will NOT send a signal through a standard balanced cable.

Tom

 

[boingoman]

Using a balanced cable when plugging a non balanced device into a balanced device results in a loss of 6 db since there will be nothing connected to one wire

That really depends on the gear being used......transformer, servo, and impedance-balanced ins and outs don't exhibit the 6db loss.

 

[boingoman]

I have an acoustic bass that will NOT send a signal through a standard balanced cable.

Tom

The bass just isn't wired to utilize that kind of cable and transfer it to a blanced input. It certainly could be.

 

[altitude909]

That really depends on the gear being used......

An unbalanced device will have a TS jack so if you plug a TRS plug into it, one of the legs will be open. When the signal is recombined in the balanced device, it will only have half the signal it should and the result will be a loss of signal strength, unless I a missing something

 

[boingoman]

An unbalanced device will have a TS jack so if you plug a TRS plug into it, one of the legs will be open. When the signal is recombined in the balanced device, it will only have half the signal it should and the result will be a loss of signal strength, unless I a missing something

Sorry, I went into more detail, probably after you saw my post. I was pretty surprised to learn about this myself. Here's a link to a Rane document that partly goes into it, I came across it a couple years ago, it made me curious so I did more research.

http://www.rane.com/note124.html

It's pretty much the now-common opamp differential inputs and outputs that exhibit the 6db loss. Since they are now so common, being cheap, small, and reasonably effective as balanced in/out devices, the idea that unbalanced means 6db less than balanced has kind of entered the collective consciousness.

That article also helped me with some odd gain staging things I would come across, where my signal would clip in odd places, and I couldn't explain it.


ps- the Rane site has tons of great info, as does the Jensen transformer site.

 

[altitude909]

Sorry, I went into more detail, probably after you saw my post. I was pretty surprised to learn about this myself. Here's a link to a Rane document that partly goes into it, I came across it a couple years ago, it made me curious so I did more research.

http://www.rane.com/note124.html

It's pretty much the now-common opamp differential inputs and outputs that exhibit the 6db loss. Since they are now so common, being cheap, small, and reasonably effective as balanced in/out devices, the idea that unbalanced means 6db less than balanced has kind of entered the collective consciousness.

That article also helped me with some odd gain staging things I would come across, where my signal would clip in odd places, and I couldn't explain it.


ps- the Rane site has tons of great info, as does the Jensen transformer site.

Good link, the rane site is my bible on many a topic

 

[SonicAlbert]

What I do is look at the type of connectors on each unit in my rack, and then wire accordingly. I use all balanced/unbalanced patchbays.

So for example, if the rack unit has balanced connectors I'll wire it with a balanced cable on both ends. If the unit has only unbalanced connectors I'll wire the rack unit end unbalanced and the other end balanced, so in other words TS to TRS. This does not balance the signal, but it does allow equipment at both ends of the cable to see the type of connection they want to see.

This also allows me to use all TRS cables to make connections at the front of the patchbay.

So again, the cable type depends on the equipment itself.

 

[Ford Van]

Foil shields perform better. As I recall, braided shield's only offer 95% coverage. The flip side is that foil shields are less durable and will eventually crack if flexed often.

If you are making microphone/instrument cables, use the braided shield as it is more durable.

For line level connections that will not get moved around much, use foil shield as they will reject RFI much better.

ALWAYS wire the shield to ground! Some foil shield cable comes with a "drain" that will accomplish this. I forgot the science of it, but not having the shield going to a ground leads to problems.

 

[Testing123]

It's pretty much the now-common opamp differential inputs and outputs that exhibit the 6db loss.

You can duplicate what's going on with the opamp style outputs by using a center-tapped transformer and grounding the center tap. You then have two out of phase signals referenced to ground, just like an opamp differential output.

-Keith

 

[Robert D]

You can duplicate what's going on with the opamp style outputs by using a center-tapped transformer and grounding the center tap. You then have two out of phase signals referenced to ground, just like an opamp differential output.

-Keith

Yes you do......can I get a witness!