In this case, increase the volume of the portable player.

在这种情况下，增加便携播放音量。

We recommend them highly when used with a portable player and headphone amp.

我们给予他很高的评价是在便携设备加上耳放的情况下.

If you are looking for a good CD portable player without the radio, this is it.

如果你正在寻找一个好的光盘没有收音机便携播放器，这是它。