Whether it's a moving coil type or a moving magnet type or any of the variants thereof, the signal comes off a coil of wire. At either end of the coil, the signal looks the same, except for its being opposite in phase. So, a cartridge is an inherently balanced output device. When you run it into a typical standard single-ended phono stage, you make an arbitrary choice to take the signal off one end of the coil and to ground the other end. But there is no need to connect to ground. In balanced mode, you just connect the coil to another identical circuit. Because the two signals are 180 degrees out of phase, any noise common to both signals is cancelled. You get a bit more gain in balanced mode and that advantage of noise cancellation, known as Common Mode Rejection.
Brrgrr, usually you won't want an XLR to XLR phono cable. Usually you will want a DIN to XLR cable, to connect your cartridge to a balanced phono input. Yes, they are made, can often be custom-made too.
Brrgrr, usually you won't want an XLR to XLR phono cable. Usually you will want a DIN to XLR cable, to connect your cartridge to a balanced phono input. Yes, they are made, can often be custom-made too.