Усилители мощности стерео — Matrix Audio MA-1

The MA-1 is the first Class AB power amplifier from Matrix Audio, a Chinese maker better known for digital products. It belongs to the M-Series system, where it is designed to work with the MS-1 streamer and the MP-1 preamplifier, and the owner may operate it in stereo, in dual mono or bridged into a single high-power channel. Matrix Audio builds the chassis around a fully independent dual-channel layout, from the mains transformers onwards.

Key specs that matter

Operating in stereo, the MA-1 is rated at 2 x 250 W RMS into 8 ohm and 2 x 450 W RMS into 4 ohm, and it accepts speaker loads from 2 to 16 ohm. Bridged, it delivers 500 W into 8 ohm or 900 W into 4 ohm with loads of 4 to 16 ohm. The XLR input presents 40 kohm and the RCA input 20 kohm, with sensitivity of 1.48 V RMS in stereo or mono mode and 1 V RMS when bridged. Gain is switchable between +30 dB and +24 dB. Response is flat within 0.15 dB from 20 Hz to 20 kHz and reaches 160 kHz at the -3 dB point. Signal to noise ratio is 119 dB A-weighted at +24 dB gain and 123 dB at +30 dB gain. THD+N stays below 0.02 percent at 250 W into 8 ohm in stereo and below 0.06 percent at 500 W bridged. Crosstalk is -125 dB, and the damping factor is 350 into 8 ohm at 1 kHz. The chassis is 430 mm wide, 518 mm deep and 201 mm high, and weighs 42.4 kg.

Engineering and use context

Each channel uses ten high-power ON Semiconductor transistors in a push-pull output stage, run in parallel to lower output impedance. The bias current is high, which explains a static consumption of up to 300 W. Left and right channels have independent transformers, giving 1250 VA in total, with main rails of plus and minus 80 V and 190,000 uF of filter capacitance. An H-shaped aluminium frame built from 20 mm CNC-machined plates holds a symmetrical layout for the two channels. Cooling is handled by a 188 mm fan controlled by a microcontroller that monitors temperature, working through an isolated duct.

Pairing

Switchable gain makes it easier to suit preamplifiers with differing output levels, with the lower setting also yielding the quieter noise floor per volt of input. The MP-1 preamplifier and MS-1 streamer from the same M-Series complete a matched chain, and a second MA-1 in bridged mode is an upgrade path for driving each speaker from its own chassis.

Alternatives

Matrix Audio lists no other stereo power amplifier in its current range besides the MA-1.