-And since phono cartridges are balanced, it is actually surprising that balanced phono sections did not appear sooner! When we built the first one in 1989, we thought that someone had done it before us, as it seemed the logical thing to do. But apparently the idea of balanced lines was/is foreign to high end audio, which is a shame because they have been so successful for over 50 years in the recording industry.
Balanced lines were created with the intent of eliminating cable problems and differences but the high end community has preferred to throw money at single-ended cables instead. While the techniques has proven successful, it has hardly been economical :)
Balanced operation also gives you lower noise both in the cable and in the circuitry. A differential amplifier, one of the basic building blocks of a balanced phono circuit, has *6db* less noise than its equivalent single-ended circuit! In practice you get a little less than that, but over successive stages of gain this means a lot- 10 db less noise for example in only 2 stages of gain. This allows for greater simplicity (less stages of gain) which translates to being closer to the music.