untuned amplifier

例句：

1. 1.The radio was tuned to the wrong station.
   收音机调到了一个错误的电台。
2. 2. The guitar strings were untuned when he first tuned them.
   他第一次调弦时，吉他的弦没调好。
3. 3.The piano is out of tune; it needs tuning.
   钢琴音不准了，需要调音。