Усилители мощности стерео — Anthem MCA 225 GEN 2

The MCA 225 Gen 2 is the two-channel member of the second-generation MCA power amplifier series from Anthem, which also includes three- and five-channel versions at the same per-channel rating. Anthem designs and manufactures the MCA range in Canada and styles it to match its AVM 90 and AVM 70 processors.

Key specs that matter

Continuous output, measured from 20 Hz to 20 kHz at under 1% THD, is 225 W per channel into 8 Ohm, 400 W into 4 Ohm and 600 W into 2 Ohm. At 100 W, THD is 0.0010% at 1 kHz and 0.015% at 20 kHz, with ITU-R intermodulation at 0.0005% and SMPTE at 0.002%. Signal-to-noise is 120 dB IEC-A referenced to 225 W. Frequency response holds within 0.1 dB from 20 Hz to 20 kHz into open circuit, 8 and 4 Ohm, and within 0.2 dB into 2 Ohm. Power bandwidth reaches 90 kHz at -3 dB at 200 W into 8 Ohm, slew rate is 30 V/us, damping factor is 300 from 20 Hz to 1 kHz and channel separation exceeds 65 dB. Input sensitivity is 1.5 V RMS for full output, voltage gain is 29 dB, and input impedance is 10 kOhm on RCA and 15 kOhm on XLR. Height is 16.9 cm (4U when rackmounted), width 43.8 cm and depth 46 cm, and the unit weighs 18 kg.

Engineering and use context

Each channel uses 8 bipolar output devices so that the load is spread across more transistors. Supply duties fall to a custom low-flux toroidal transformer, with filter capacitors, regulated supply rails and oversized aluminium heatsinks. For the Gen 2 redesign Anthem cut back internal cabling, fitted improved input transistors and minimised both supply impedance and cable inductance. Advanced Load Monitoring monitors internal temperature, current and voltage while staying out of the signal path, which therefore carries no fuses. If a fault occurs, unaffected channels keep playing and normal operation returns automatically, with a front-panel LED showing status. Typical consumption is 240 W, idle draw is 35 W, high-output draw is 500 W and standby use is 1.0 W, and inrush current has been reduced.

Pairing

Each channel has one balanced XLR and one RCA input, and larger binding posts accept big speaker cable connectors. Switch-on can be manual, via 12 V trigger or by input signal sensing. An IEC socket with a 14 AWG cord is supplied, and the amplifier runs on 108 to 132 V at 60 Hz or 198 to 264 V at 50/60 Hz depending on version.

Alternatives

Anthem's STR Power Amplifier offers two class AB channels of 400 W into 8 Ohm, each driven by 16 bipolar output transistors and fed by its own toroidal transformer.