ヤマハ | P-S Series - パワーアンプ - 概要,Yamaha P2500S P-Series power amplifier — 250 watts RMS x 2 at 8 ohms (310W x 2 at 4 ohms) at Crutchfield,Yamaha P2500S Two-Channel Power Amplifier, 250W into 8 Ohm Stereo, 30K Ohms Input Impedance, 20Hz - 50kHz Frequency Response,Yamaha P2500S - Two-Channel Power Amplifier,Yamaha P2500S,