Features A-S1000 Natural Sound Stereo Amplifier HiFi Began with Yamaha...Yamaha's involvement with and passion for music goes back more than a century, to when we built our first reed organ in 1887. Now we are the world's leading producer of pianos and other musical instruments, and are involved with music in many other ways as well. We manufacture professional recording equipment, we design concert halls and we assist artists at concerts with set up and sound tuning. This knowledge and experience benefits our production of audio components in many ways. We introduced our first HiFi (High Fidelity) turntable in 1954, becoming the first company to actually use the term “HiFi.” Thereafter we were one of the first to offer mass-produced, high quality audio equipment, and introduced many legendary stereo components. We hope you enjoy the genuine HiFi experience of Yamaha Natural Sound. MAIN FEATURES High Performance Amplifier that Brings Out the Best of Other Components Floating Balanced Power Amplifier Triple Parallel Electronic Volume and Tone Controls Fully Discrete Phono Equalizer and MC Head Amp Symmetrical Construction Specially Designed Feet Specs Specifications Minimum RMS Output Power (8 ohms, 20 Hz—20 kHz, 0.02% THD) 90 W + 90 W (4 ohms, 20 Hz—20 kHz, 0.02% THD) 140 W + 140 W Maximum Power (8 ohms, 1 kHz, 10% THD) 115 W + 115 W (4 ohms, 1 kHz, 10% THD) 190 W + 190 W Dynamic Power/Channel (8/6/4/2 ohms) 105 W /135 W /190 W /220 W Damping Factor (8 ohms, 20 Hz—20 kHz) 160 Input Sensitivity/ Impedance CD, etc. 150 mV/47 k-ohms; Phono MM 2.5 mV/47 k-ohms; Phono MC 100 μV/50 ohms; Main In 1 V/47 k-ohms Frequency Response CD,etc. to Speaker Out, Flat Position 5 Hz–100 kHz +0 dB/-3 dB; CD,etc. to Speaker Out, Flat Position 20 Hz–20 kHz,+0 dB/-0.3 dB RIAA Equalization Deviation Phono MM 20 Hz—20 kHz, ±0.5 dB; Phono MC 20 Hz—20 kHz, ±0.5 dB Total Harmonic Distortion (20 Hz–20 kHz) CD, etc. to Speaker Out 0.015% (90 W/8 ohms) / Phono MM to Rec Out 0.005% (2 V) / Phono MC to Rec Out 0.05% (2 V) Signal-to-Noise Ratio [IHF-A Network] CD, etc. (S: 150 mV, Input Shorted) 98 dB / Phono MM (S: 5 mV, Input Shorted) 93 dB / Phono MC (S: 500 μV, Input Shorted) 85 dB Residual Noise (CD, etc., IHF-A-Network) Channel Separation (1 kHz/10 kHz) CD, etc., Input 5.1 k-ohms Terminaled 74 dB/54 dB Phono MM, Input Shorted, Vol: -30dB 90 dB/77 dB Phono MC, Input Shorted, Vol: -30dB 66 dB/65 dB Tone Control Characteristics Bass Boost/Cut (at 50 Hz) ±9 dB / Bass Turnover Frequency 350 Hz / Treble Boost/Cut (at 20 Hz) ±9 dB / Treble Turnover Frequency 3.5 kHz Audio Muting -20 dB (approx.) Dimensions (W x H x D) 435 x 137 x 465 mm 17-1/8” x 5-3/8” x 18-5/16” Weight 22 kg 48.5 lbs.