With the Onkyo A-9555 integrated digital amplifier, sound quality takes precedence over all else. By using Onkyo's exclusive Vector Linear(VL) Digital technology to remove any spike noise before it introduces errors into the inversion timing, it is possible to get a highly accurate analog-to-digital conversion. At the heart of the A-9555 is a Pure Stream Power Supply?essentially a large power transformer?that ensures that you always have the on-demand power for the clarity and detail of a range of musical genres. By integrating the fundamentals of audio amplification with the potential of digital amplification, the A-9555 is a revelation in superior audio reproduction. Pulse Width Modulation (PWM) and Onkyo's Vector Linear (VL)Digital Technology combine with Optimum Gain Volume Circuitry to provide the superior performance expected by today's audiophile. Output Level and Impedance - Rec out - 200 mV/2.2 k-ohms / Phono Overload 70 mV (MM, 1 kHz, 0.5 %)/ Frequency Response 10 Hz-60 kHz (+ 1, - 3 dB, CD) Signal-to-Noise Ratio - 100 dB (CD, IHF-A), 70 dB (Phono, IHF-A)/ Speaker Impedance - 4 ohms-16 ohms Power Supply - AC 120 V, 60Hz Dimensions (W x H x D) - 17-1/8 x 5-13/16 x 16-15/16 inches