RFRB Kenwood Excelon XR401-4 Reference Series Class D 4 Channel Power Amplifier Kenwood's Excelon Reference Series XR401-4 4-channel amplifier will add clarity and punch to your sound, as it powers each of your front and rear speakers with 75 watts RMS. If you're adding bass first, you can use the amp in 2-channel mode to drive a couple of subwoofers with up to 200 watts RMS each. Then later you can switch the amp over to your main speakers when you get a sub amp. This Excelon Reference Series amplifier has ultra-high-frequency response up to 40,000 Hz, reproducing sounds that help define audio tone and space even though beyond the range of hearing. Fix this amp up with a nice set of Kenwood high-res Reference Series speakers, and you can enjoy the extended detail and powerful musical imaging of your high-res FLAC or DSD files. Product Highlights: Refurbished 4-channel power amplifier 75 watts RMS x 4 at 4 ohms (100 watts RMS x 4 at 2 ohms) 200 watts RMS x 2 bridged output at 4 ohms (4-ohm stable in bridged mode) CTA-2006 compliant Class-D amp design Frequency response: 20-40,000 Hz Variable low- and high-pass filters (50-200 Hz or 2.5k-10k Hz, 12 dB/octave) Preamp inputs only Fuse rating: 30A x 2 4-gauge power and ground leads recommended