M-70 vs M-4
The M-4's power @ 8ω is 120W against the M-70's 200W, its signal-to-noise 118 dB against 124 dB, and its thd 0.005% against 0.002%. Both share damping factor (>200).
AI-generated product photo — not official manufacturer imagery.
AmplifiersPower AmplifiersDiscontinued
Estimated price (community-sourced)
$450
Around — community and catalog average, updates slowly
About the M-70
The Yamaha M-70 Natural Sound Stereo Power Amplifier is a premium power amplifier from 1982-1984 that combines outstanding low-distortion power performance with incredible power efficiency. It features Yamaha's proprietary Zero Distortion Rule (ZDR) system, Linear Transfer Bias circuitry, and the "X" Power Amplifier system to minimize crossover distortion and heat generation. The ZDR circuit uses a distortion detector and summing circuit to monitor output and feed back a 180° out-of-phase distortion signal to cancel virtually all distortion, even accounting for back EMF from speakers. The amplifier delivers clean, accurate music reproduction with negligible crossover distortion levels and operates under optimum conditions at all times.
Specifications
Power Specifications
Amplification power output and characteristics
- Power @ 8Ω
- 200W @ 8Ω
- Power @ 4Ω
- 250W @ 4Ω
- Damping Factor
- >200
Analog Output
Analog signal output specifications
- THD
- 0.002%
- SNR
- 124 dB
- Output Voltage
- 1.4V RMS
- Output Impedance
- 25Ω
Connectivity
Input and output connections
- Bluetooth
- No
- Wi-Fi
- No
- Ethernet
- No
- Analog Inputs
- RCA
- Analog Outputs
- Speaker terminals
Physical Dimensions
Size, weight, and appearance
- Dimensions
- 435 × 133 × 380 mm (W × H × D)
- Weight
- 13.7 kg (30 lbs)
Key Specifications
Power: 200W
Specifications are community-contributed and may not be accurate or complete. Verify all details with the manufacturer before making purchasing decisions. Terms & Conditions