Усилители мощности стерео — Bryston BD-225

The BD-225 is a power amplifier from Bryston's BD series, the first Class D amplifiers from the Canadian company, which is otherwise known for linear designs. The same chassis can carry one to six independent amplifier channels, so the BD-225 is available in stereo and multichannel form. A two-channel version costs USD 3,495, and a one-channel version CAD 4,135.

Key specs that matter

Each channel delivers 225 W RMS into 8 ohms and 450 W into 4 ohms. With every channel working, the chassis supplies 1,250 W in total, and 100 ms bursts reach 3,750 W. Input sensitivity is 1.5 V, voltage gain is 29 dB, and noise lies 103 dB below full output. Frequency response reaches 1 Hz to 45 kHz at -3 dB into 6 ohms. Storage capacitance in the power supply totals 108,000 µF. Signals enter through XLR or RCA sockets, with a 12 V trigger alongside. Mains operation is 115 or 230 V. The case is 133 mm high, 450 mm wide and 425 mm deep, and it weighs 24 kg.

Engineering and use context

Bryston designed its own Class D modules for the BD series, which use pulse width modulation to switch the output devices at high frequency, and combined them with a linear power supply based on a toroidal transformer instead of the switching supplies common in Class D amplifiers. This keeps a large reserve of stored energy for peaks in the music. The modular chassis means one design covers stereo, three-channel and larger home cinema configurations up to six channels, each channel independent. Class D output stages convert more of the supply energy into output than linear stages. The gain matches that of many other power amplifiers, so it slots into systems built around existing preamplifiers and processors. The warranty runs 20 years.

Pairing

Preamplifiers and AV processors connect over balanced or unbalanced cables. With its high 4 ohm rating, it suits low-impedance speakers such as Bryston's own T10 range. A six-channel chassis covers the front and surround channels of a home cinema system from one case. Six channels at full individual output would slightly exceed the all-channel rating, so in a fully loaded chassis each channel has a little less than its individual maximum.

Alternatives

The Bryston BD-325 uses the same chassis and modular layout with 325 W per channel into 8 ohms and 650 W into 4 ohms, and 144,000 µF of storage capacitance.