A truly balanced circuit has a pair of identical signal paths for each channel whereas an unbalanced circuit has only one signal path per channel. The duplicate signal path is for carrying an inverted version of the standard signal.
You can very quickly tell from glancing inside of an amp or preamp if it is a balanced or differential circuit. If it is, you will see four of every key part in the signal path (left channel +, left channel -, right channel + and right channel -). An unbalanced or single ended circuit will only have two of each component (left channel + and right channel +).
For a truly balanced system, every component from the source through the amplifier must have balanced circuitry. The noise reducing benefits of balanced operation occur when at the ouput of your amplifier, the inverted signal is inverted again and then summed with the standard signal. Any noise that was picked up via the signal paths in your equipment and any of your interconnect cables will be cancelled out, while the signal level will be doubled moving it 6db above the now lower noise floor.
You can very quickly tell from glancing inside of an amp or preamp if it is a balanced or differential circuit. If it is, you will see four of every key part in the signal path (left channel +, left channel -, right channel + and right channel -). An unbalanced or single ended circuit will only have two of each component (left channel + and right channel +).
For a truly balanced system, every component from the source through the amplifier must have balanced circuitry. The noise reducing benefits of balanced operation occur when at the ouput of your amplifier, the inverted signal is inverted again and then summed with the standard signal. Any noise that was picked up via the signal paths in your equipment and any of your interconnect cables will be cancelled out, while the signal level will be doubled moving it 6db above the now lower noise floor.