Усилители мощности стерео — AVM SA 8.3 S

The SA 8.3 S is a stereo power amplifier from AVM's Ovation S series, presented during the company's 40th anniversary year to complete that range alongside the MA 8.3 S monoblock. Its front end is a newly developed tube stage wired as an anode follower, which drives balanced circuits and MOSFET output stages working in Class A/AB, and it is handmade in Germany, with a launch price of EUR 25,199.

Key specs that matter

Continuous power is specified as more than 230 W per channel into 8 ohms, more than 420 W into 4 ohms and more than 700 W into 2 ohms, and AVM quotes up to 400 W per channel as headline power. Gain is a factor of 30, or 29.5 dB. Input sensitivity is 1.25 V on both inputs, with 20 kOhm impedance on RCA and 40 kOhm on XLR. Small-signal frequency response runs from below 1 Hz to above 100 kHz at -3 dB, and power bandwidth at 25 W into 4 ohms spans 5 Hz to beyond 50 kHz. Distortion stays below 0.02 percent and intermodulation below 0.01 percent, signal-to-noise ratio exceeds 94 dB(A), slew rate is above 15 V/us, rise time is 10 us and damping factor exceeds 400 into 8 ohms.

Engineering and use context

Each channel uses 24 MOSFETs with current-source-stabilised output stages, and a dual differential input stage feeds them. The power supply is built around two low-stray 1000 VA toroidal transformers, one per channel, with 270,000 uF of reservoir capacitance in each channel. The whole analogue path is DC-coupled with automatic offset compensation, which removes coupling capacitors from the audio signal, and integrated power filtering covers all relevant supply voltage ranges. Maximum mains draw is 3500 W, idle consumption is 120 W and standby stays below 0.5 W. The aluminium chassis measures 420 x 432 x 253 mm and weighs 42 kg, in Silver, Brushed Black or the CELLINI version with a chrome fascia, and it ships in a flight case.

Pairing

The high current capability and the low-impedance rating suit low-impedance and demanding loudspeakers. A dimmable OLED graphic display, a 5 to 20 V DC trigger input and AVM's AIR Trigger (AVM Intelligent Remote) let it power up in sync with an AVM preamplifier such as the PAS 8.3 S. For systems that need more power, the MA 8.3 S monoblock bridges two amplifier stages of the same platform for up to 1,200 W. The warranty is 2 years, extended to 4 years with online registration.

Alternatives

AVM also makes the earlier Ovation SA 8.3 stereo power amplifier, rated at 250 W into 8 ohms.