Unbalanced Cable Into Balanced Input

In both cases one jack is normally used for each audio channel left and right.

Unbalanced cable into balanced input.

A balanced circuit needs to be three wires positive negative and ground all the way through. The diagram above shows how the cable works. A balanced audio cable has a ground wire but it also carries two copies of the same incoming audio signal sometimes referred to as a hot positive and cold negative signal. If you start with an unbalanced source and an unbalanced cable two wires that signal will remain unbalanced when you plug it into a balanced input.

Even if you plug a balanced cable into an unbalanced output jack the signal will be unbalanced see the downsides of unbalanced above. Unbalanced line level connections are usually implemented with rca jacks for audio while balanced line level connections typically utilize dual 3 pin xlr jacks for both the input and output. Where it gets a little more custom so to speak is ts or rca outputs to xlr inputs for example. The cd player has balanced outputs on xlr jacks but not dual dacs per channel.

The cd player creates the balanced signal by converting the unbalanced signal from the single dac to balanced with a circuit called a phase splitter the audio signal has just been subjected to an additional active stage usually an op amp. The signal wires pass an identical audio signal through each wire while the surrounding ground wire works the same as in unbalanced cables shielding the signal wires from external electronic interference. Two signal wires and a ground wire. The structure of a balanced audio cable is similar to an unbalanced cable with one addition.

The advantage of using balanced cables to connect between balanced outputs and balanced inputs is that balanced connections have better noise rejection thanks to a second inverted signal that has equal resistance to ground as the initial signal this inverted or reverse polarity signal is used to cancel noise and to make the signal more robust. Almost any combination of audio connection is possible but not necessarily standard or stock. Having cables with this kind of output makes it easy to directly connect unbalanced sources such as guitar effects directly into recording gear daws and signal processors with balanced inputs.