18.09.2025 08:35 | ~1 minute read
Riviera Audio Labs has released a new monophonic power amplifier Riviera Audio AFM70, which develops up to 70 W into an 8 Ohm load and up to 140 W into 4 Ohms. These are very solid figures for the hybrid amplification circuit used here – a vacuum tube is used in the preamplifier stage, and the output stage is built on semiconductors.

Riviera Audio AFM70 uses all three of its proprietary engineering principles – no feedback, hybrid topology and operation in pure class A. Voltage amplification in the preamplifier stage is performed by 1 x ECC82 / 12AU7 triodes. The output stage consists of twelve transistors, each of which can dissipate up to 150 W.

The amplifier is powered by a large power transformer with a capacity of more than 400 VA, using an improved P-shaped filter and distributed capacitance. The total capacity of the power supply filter exceeds 100,000 μF. The deliberate absence of current limiting systems ensures stable operation of the amplifier even with a complex load.

This product is in the Hi-Fi and High End Electronics and Acoustics database
Model name
AFM70
Input sensitivity (mV)
220mVrms for 1W/8 ohm (2.83Vrms); 1.87Vrms for 70W/8 ohm (24Vrms)
Input impedance (balanced) (Ω)
47 000
Input impedance (single-ended) (Ω)
47 000
Output impedance (balanced) (Ω)
N/A
Output impedance (single-ended) (Ω)
N/A
Max current (A)
N/A
Output power (8Ω) (W)
70
Output power (4Ω) (W)
N/A
Gain (dBu)
22
Frequency response low +/- 3dB (Hz)
N/A
Frequency response high +/- 3dB (Hz)
N/A
Signal to Noise Ratio (dB)
N/A
Total Harmonic Distortion + Noise (0% global feedback) (%)
N/A
Total Harmonic Distortion + Noise (100% global feedback) (%)
N/A
Max power consumption (W)
N/A
Damping factor
N/A
Dimensions (mm)
340 × 485 × 195
Weight (kg)
30
Official link