Denon PMA-50 Compact Digital Amplifier Advanced AL32 Processing DAC master clock design with low jitter clock. New Digital Amp, 50W+50W (4ohms, 1kHz, THD 0.004%) USB-B input for a computer (supports 192/24 and DSD High-Res Audio) Bluetooth (supports APT-X and NFC) for smartphone / tablet.Amp Gain Selector for sasy Head phone listening. Bass Control :  8 dB at 100 Hz