русский
предварительный усилитель португальский
pré-amplificador испанский
preamplificador каталонский
preamplificador 
Audio amplifier with output power not sufficient to control a loudspeaker; circuit that prepares an audio signal for processing or further amplification.
1
I now have a pre-amp for my turntable with, like, tubes in it.
2
It has its own analog-digital converter, and uses its own pre-amp, allowing it to handle sound up to 125dB without blowing out.
3
However, because there's no pre-amp in the setup and you can only have one input going into the iPhone I've found this quite limiting.
португальский
испанский
каталонский