Усилители мощности стерео — Anthem P2

Anthem's P2 is a stereo power amplifier with a Class AB output stage, launched in 2005 as the Statement P2 and still listed by the company as its reference stereo amplifier. It is built in Mississauga, Ontario, and its principal designer is electrical engineer Marc Bonneville. List prices were USD 4,999.99 and CAD 5,999.99, and Anthem gives a limited five-year warranty that covers both parts and labour.

Key specs that matter

Per channel the amplifier delivers, from 20 Hz to 20 kHz below 0.1% THD with one or both channels driven, 325 W into 8 ohms, 500 W into 4 ohms and 675 W into 2 ohms. Voltage gain is 29 dB, and 1 V RMS at the input yields 100 W into 8 ohms. Input impedance is 22 kohm balanced and 18 kohm unbalanced. THD+N measures 0.0007% at 1 kHz and 0.008% at 20 kHz, CCIF intermodulation is 0.00019% at full power, and noise lies 125 dB below the rated output with A-weighting. Response is flat within 0.15 dB from 20 Hz to 20 kHz and within 2 dB from 5 Hz to 100 kHz. Damping factor exceeds 600 at 20 Hz and is 400 at 1 kHz, slew rate is 40 V/us, and crosstalk is -140 dB at 20 Hz. The case is 23.8 cm high, 43.8 cm wide and 57.2 cm deep and weighs 34 kg. Idle draw is 140 W and the maximum 1,800 W.

Engineering and use context

Anthem describes the layout as multi-mono - each channel has its own glass-epoxy board, heat sink and power supply with a toroidal transformer mounted behind the front panel, and no audio path is shared between channels. The input stage uses eight hand-matched low-noise bipolar transistors per side in a complementary active-load cascoded feedback circuit, and fourteen bipolar output devices per side drive the speaker. Cooling is passive, with about 7,260 cm2 of fins per channel. Instead of fuses, protection circuitry guards the amplifier, and the power supply capacitor bank is connected directly without them. Boards follow military-grade FR-4 practice with 2-ounce copper traces. Rear-panel switches reduce the XLR sensitivity by 6 dB, and the unit powers up manually, automatically on signal or from a 3.5 mm trigger.

Pairing

Any stereo preamplifier or AV processor with XLR or RCA outputs can drive it through gold-plated sockets. Oversized binding posts, also gold-plated, accept heavy speaker cable, and the low-impedance rating covers loudspeakers whose impedance dips low.

Alternatives

The Anthem STR Power Amplifier is a newer two-channel model from the STR series introduced in 2018.