balanced or not?

[ikijapan]

Hi there,

Can someone help please, I have had my home studio set up for quite some time and am trying to upgrade little things here and there and now realised I never payed any attention to balanced cables...

So here's my question:
I have a sound card that has all balanced inputs and outputs (Emu 1820),
but I have no balanced cables (except XLR mic cables of course). So, looking at my monitor I see it clearly says "balanced inputs", so that's easy, I'll replace those cables. But all of my other equipment doesn't really say either way. In particular I have a yamaha s90 keyboard, roland td-20, and marshall AVT150 amp with emulated output for DI.

I have googled all this equipment to death and have all the manuals and none of the 3 pieces of equipment say either balanced or phone jack or unbalanced anywhere...

But from the reading I have gathered that it is quite common that these types of instruments are unbalanced outputs...is there anyway to know for sure? Does anyone know about these ? On the TD-20 I am using the 8 direct outputs for best recording quality...


Thanks

 

[SouthSIDE Glen]

One tell-tale sign for a 1/4" jack is how many "clicks" it takes to plug a 1/4" plug into it. One click usually means it's a two-lead unbalanced jack, two clicks means it's a three-lead balanced jack (though it may also be able to handle unbalanced, depending on the type of gear). If it's an RCA analog jack, it's unbalanced only.

G.

 

[sjjohnston]

But from the reading I have gathered that it is quite common that these types of instruments are unbalanced outputs

I think you're right.

Typically, if it's not mentioned in the specs or anywhere, it's probably unbalanced. "Consumer-ish" stuff like keyboards and drum machines typically have all unbalanced connections, though I'm sure there are exceptions.

...is there anyway to know for sure?

For a 1/4" output: Plug in a TRS cable and see if there's any signal on the ring. There are a couple of ways to do this, some more elegant than others (the elegant ones involving the use of actual test equipment you may not have).

A reasonably elegant way: get the box you're checking on to output a signal. Plug into its output an "insert cable" (i.e. a cable with a TRS plug at one end and two TS plugs (or jacks) at the other). Connect the tip TS to an input and see if there's a signal. Assuming there is, then connect the ring TS to the same input and see if there's the same signal (virtually the same anyway).

Side-point on wiring of TRS connectors -- there are three ways these are typically used:
- Balanced connection: tip carries signal; ring carries inverted copy of same.
- Insert: tip sends signal out; ring returns it (typically, it's not completely universal)
- Stereo: tip carries left, ring carries right.
An insert cable splits the tip and ring, each to its own connector. Cables sometimes marked as "stereo splitter" cables do the exact same thing, usually with two RCA jacks on the other end from the TRS. There are also variants of the same thing for use with computers, mini-stereos, etc. some 1/8" TRSs to two 1/8" TSs, etc.
In stereo cables, right is often colored red ... so you can remember what's what with this: "Ring, red, right, returning." (It also works for understanding channel markings if you happen to be in a boat.)

Less elegant ways: connect the output with a TRS to a stereo input and see whether it's receiving any signal on the right channel. You could even do this just by plugging a pair of headphones in and seeing if you hear anything in the right ear when you're hearing something in the left. Be careful about levels, for the health of the gear and your own self.

You could also open the box and see if there's a TS or a TRS jack in there.

 

[ikijapan]

Plug the output to a stereo headphones...I like that idea, sounds easy...
does anyone else concur about this? If I plug each mono output to stereo headphones and get signal in both sides of the headphones (carefully) does that indicate a balanced output??

Thanks

 

[Farview]

Plug the output to a stereo headphones...I like that idea, sounds easy...
does anyone else concur about this? If I plug each mono output to stereo headphones and get signal in both sides of the headphones (carefully) does that indicate a balanced output??

Thanks

yes, it does.

 

[ikijapan]

Oh, thank you farview...I tried it and all the equipment I was wondering about is therefor unbalanced. Rather annoying that a $6,000 roland td-20 and $2,000 yamaha s90 are unbalanced, but oh well.

OK, so, after playing around with the search unsuccessfully, let me ask one more thing...
I thought I read somewhere that you can change a unbalanced output to a balanced one with something...what was that again? Also, is it really even necessary? I mean, let me put it this way, what do they do in the pro studios? Certainly not every piece of equipment is balanced, what if they want to record something that is unbalanced and they need 30 feet of cable?

Help me out here, thanks again everyone

 

[Farview]

Most of the time keyboards and drum machines are just plugged right into a mixer or outboard preamp.

For long runs, you would use a direct box. This balances the signal.

Having unbalanced connections is not a problem unless your cables are 40 feet long or routed next to power cables, speaker cables, ham radio antenna, etc... The first thing that happens to a signal once inside of a balaced piece of gear....the signal is unbalanced. Then it is balanced again on the way out.

It really isn't a sign of quality, it's a sign of who the manufacturer thinks will be using it.

 

[sjjohnston]

I thought I read somewhere that you can change a unbalanced output to a balanced one with something...what was that again?

A transformer does that.

As the previous poster noted, I think an easier multi-step approach (if you've got some reason to think an unbalanced line might be a problem, like if it's really long) might be:
- Try it, and see if it is a problem, that is: are you picking up noise that you think is RF interference or something?
- See if you can move the source closer to what you're plugging it into.
- See if you can move what you're plugging it into closer to the source.
- See if you've got something else you already own that won't mess up the signal chain, and that outputs a balanced signal, and get it close to the source.

 

[Robert D]

There's an argument to be made that balanced is not only not always necessary, but even not desirable. Most circuits are single ended, and are converted to balanced as a final bit of circuitry just before the output jack. Then at the other end it is immediately converted back to single ended. These conversions can be as detrimental to sound quality as A/D and D/A conversions, if implimented poorly and cheaply. It's something no one really thinks about, and we all just assume that balanced must sound better. All balanced lines do is give us common mode noise rejection of any noise picked up in the cable run, hopefully not at the expense of the original signal integrity.

 

[noisewreck]

If I understand correctly, many mastering engineers go with unbalanced connections for exactly those reasons. They just take care to have very short runs between equipment and that there are no environmental factors that could interfere with the signal.

However, for mixing/tracking/recording studios (i.e. your bedroom) that's going a bit too far. Personally, I wish my Juno-106 had balanced connectors as that thing buzzes like hell unless I run the cable mid air!

 

[sjjohnston]

There's an argument to be made that balanced is not only not always necessary, but even not desirable.

Yes, though that's relevant only if the particular box you're dealing with gives you a choice.

That is:

If you've got a box with a set of unbalanced outputs and a set of balanced outputs, it's possible that the unbalanced outputs will work "better" (in some situations), and it's possible that they won't. That really depends on what's going on inside the box. Same with inputs.

But if you've got Box A, which has one balanced output, and Box B, which has one balanced input, you're not going to improve anything by unbalancing the connection. You may not make things a lot worse, either, but you're not going to make them better. In some cases (say, for example, you're connecting to the input of a Symetrix 620), you might make things a lot worse.