I would reccomend a quick forum search on this subject.
I have read some fabulous threads here on this subject, which included the participation of the designers of some of Audiogon's most well respected gear!
Since in your post you do not state whether your gear is balanced by design, there is no simple answer.
Originally almost exclusively reserved for pro-audio use, balanced components are designed to operate in unpredictable professional working environments They offer maximal S/N (signal to noise ratios), and standardized connectivity. Today's well-designed balanced high-end equipment, when connected with balanced IC's, offers the benefits of lower noise floor and better radio frequency (RF) rejection.
On the other hand, well-designed unbalanced equipment offers sonic (and sometimes lower price) benefits which make simpler circuit topologies popular. These designs can, however, be more prone to RF noise, which has become (with Cell phone, microwave, computer, and WiFi) an increasing feature of the home environment.
Hope this helps,
If you don't find your answers by reading previous threads, please let us know more about the boxes you are connecting up.
For the music,