Unbalanced and Balanced

Frederickbass · #1 10-12-2008, 04:09 PM

Hi fellow mates,

I was wondering this morning if a head for example as a balanced output and that i plug it directly to a firewire interface that as unbalanced 1/4 input. Will my sound still be balanced ? .

thanks

**line6man** · #2 10-12-2008, 05:52 PM

going from a balanced output to a balanced input is exactly the same as going unbalanced to unbalanced...

are you familiar with how a balanced signal works?
maybe somebody has a good article or something.

there really isnt a tonal difference between balanced and unbalanced signals...
balanced signals are better at cancelling out noise, and thats the primary advantage of using them

Frederickbass · #3 10-12-2008, 06:01 PM

Quote:

Originally Posted by line6man

going from a balanced output to a balanced input is exactly the same as going unbalanced to unbalanced...

are you familiar with how a balanced signal works?
maybe somebody has a good article or something.

there really isnt a tonal difference between balanced and unbalanced signals...
balanced signals are better at cancelling out noise, and thats the primary advantage of using them

but from a balanced output to an unbalanced output ? will the signal still be balanced ?

Catfishheads · #4 10-12-2008, 06:16 PM

No, it will not remain balanced. Unless your destination device has 1/4 inch TRS type connectors which can be balanced. Check that. If they are TRS, the tip will be positive, the ring negative and the shield ground. There are adapter cables that will take you from balanced XLR to balanced TRS. If however, that 1/4 inch input really is unbalanced as you say, then your signal cannot remain balanced through the input circuit of the destination device.

A balanced audio signal has a positive, a negative and a shield. The negative is the opposite polarity as the positive. As the positive voltage swings positive, the negative voltage swings negative by the same amount.

Normally, you plug balanced sources into balanced destinations and unbalanced sources into unbalanced destinations. But there are times you don't match up. In those cases, I like to have a few Jensen transformer balancing boxes around. These are expensive though. So if you must....

If you have a balanced source you wish to connect to an unbalanced destination, you should use the positive signal and the shield (ground) only. Do not connect the negative signal. There are exceptions to this rule. Some output electronics have the ability to auto detect a shorted negative and adjust accordingly. Better not to try it if you don't know for sure.

If you have an unbalanced source you wish to connect to a balanced destination, ideally, you should connect the source positive to the destination positive and the source shield (ground) to the destination negative. This actually can help you if you have any so-called ground loop hum. Any hum potential between the interconnected gear will come right through if you are connecting unbalanced to unbalanced. But if you plug unbalanced into balanced the way I have described, it is possible to suppress that hum by 40dB or more (depending on the CMR performance of the destination's input circuit). You may have to experiment with the shield connection a bit. Some like to float the shield connecting it only at the source in this unbalanced-to-balanced case.

Frederickbass · #5 10-12-2008, 06:24 PM

Quote:

Originally Posted by Catfishheads

No, it will not remain balanced. Unless your destination device has 1/4 inch TRS type connectors which can be balanced. Check that. If they are TRS, the tip will be positive, the ring negative and the shield ground. There are adapter cables that will take you from balanced XLR to balanced TRS. If however, that 1/4 inch input really is unbalanced as you say, then your signal cannot remain balanced through the input circuit of the destination device.

A balanced audio signal has a positive, a negative and a shield. The negative is the opposite polarity as the positive. As the positive voltage swings positive, the negative voltage swings negative by the same amount.

Normally, you plug balanced sources into balanced destinations and unbalanced sources into unbalanced destinations. But there are times you don't match up. In those cases, I like to have a few Jensen transformer balancing boxes around. These are expensive though. So if you must....

If you have a balanced source you wish to connect to an unbalanced destination, you should use the positive signal and the shield (ground) only. Do not connect the negative signal. There are exceptions to this rule. Some output electronics have the ability to auto detect a shorted negative and adjust accordingly. Better not to try it if you don't know for sure.

If you have an unbalanced source you wish to connect to a balanced destination, ideally, you should connect the source positive to the destination positive and the source shield (ground) to the destination negative. This actually can help you if you have any so-called ground loop hum. Any hum potential between the interconnected gear will come right through if you are connecting unbalanced to unbalanced. But if you plug unbalanced into balanced the way I have described, it is possible to suppress that hum by 40dB or more (depending on the CMR performance of the destination's input circuit). You may have to experiment with the shield connection a bit. Some like to float the shield connecting it only at the source in this unbalanced-to-balanced case.

thank you really for taking the time to answer my question. Take care