Agucela, What that means is that the circuit inside is single-ended (often abbreviated "SE"), but the maker has also provided an XLR jack for output to some other device that may have an XLR input jack. It's well that the manufacturer admits this; many just stick an XLR jack on the back and leave the end user to figure out whether or not the circuit inside is truly balanced. Hooking an SE circuit to an XLR jack is very easy to do; only one pin in the XLR jack is needed to carry the SE output signal. Balanced operation is a different deal, and there is much controversy among audiophiles around what is best, balanced vs SE. Operation in true balanced topology requires nearly a doubling of the parts count in the circuit and thus is more expensive to implement. Theoreticians and engineers will often argue that balanced topology is superfluous unless you are running very very long runs of cable, like hundreds of feet, as in a recording studio. However, audiophilia is not always a logical disease, and some audiophiles are staunch advocates of balanced topology even when using much shorter runs of cable. Balanced operation does afford a kind of noise cancellation that is not available in SE operation, called Common Mode Rejection (CMR), which is why it is preferred with very long runs of cable. Whether that is a critical advantage or not in home audio is the subject of debate, but in true balanced mode one seldom runs into problems of hum due to ground loops or differences in voltage between one ground and another in a connected system. On the other hand, those who prefer SE devices say that the complexity of balanced circuits leads to colorations of the sound. (I've never heard such a phenomenon.) I own two systems; one is basically balanced from input to output, including the cartridge hook-up to the balanced phono stage. The other is SE all the way. Both are very quiet. I love them both. Bottom line: I would not let the topology (balanced vs SE) determine what phono stage you choose, unless the rest of your system is also truly balanced, in which case I would tend to favor a true balanced phono stage.
