想請教 unbalance 訊號轉成 balance 訊號的問題。我看有產品能將-10的 unbalance變成+4 的balance訊號。這樣的好處是否包含雜音小？因為如果只是訊號變強,加一個buffer preamp 就可以了不是嗎？
Balanced and Unbalanced 主要差異在於介面間的grounding and shielding ,single phase transmitting or bi-phase transmitting,,,所以雜音少,,signal levels 引起的雜音和 Amp 的品質比較有關係,,,,, UNBALANCED CONNECTIONS An unbalanced line uses only two conductors with one being at or near ground potential, while the other conductor is the hot or high side of the line. The line is said to be unbalanced because the two conductors are of unequal potentials with respect to ground.,,,,One is near ground and the other has some greater value. Unbalanced lines are the most common interface between consumer grade audio components such as tape decks, CD players, and DJ equipment.,,,,Unbalanced connections work well for short cable runs in low noise environments. Unbalanced lines are more susceptible to RF noise and other interference and are not suitable for cable runs of more than 20 feet or complex setups where RF noise may be a problem. The most common hum and noise problems associated with unbalanced lines are RF noise induced by AC power lines, and ground loops between components..... BALANCED CONNECTIONS Balanced lines require the use of three terminals rather than two. One conductor (shield) will be connected to ground, and the signal will be carried by two identical conductors which carry the same voltage but with opposite polarity with respect to ground. The line is said to be balanced since the two signal carrying conductors are of equal (though opposite) potential. Balanced lines are useful for eliminating unwanted noises. Induced noise such as that caused by RF interference will effect all conductors in a cable equally. Since a balanced line contains two signal carrying conductors of equal magnitude but opposite polarity, noises induced along the cable path cancel each other out when they reach the destination load. This makes balanced lines the interface of choice for professional applications, long cable runs or anywhere that induced noises might be a problem.
把unblanced的souce接到balanced input jack上面 cable還是不能超過兩公尺 source端沒有接地 用了線等於空接 如果mixer端屬於會自己判斷balanced/unbalanced的 應該也是判斷成unbalanced吧