Усилители мощности стерео — Arcam PA410

Arcam, part of HARMAN International, offers the PA410 as a four-channel power amplifier. It sits in the same range as the two-channel PA240, but uses Class AB circuitry rather than Class G, and it can be used either with four channels or as a two-channel amplifier. This makes it suitable for adding channels to an AV receiver or processor, or for powering a stereo pair from a compact chassis.

Key specs that matter

With four channels driven, output is 50 W per channel into 8 ohms and 70 W per channel into 4 ohms, measured from 20 Hz to 20 kHz. In two-channel use the figures rise to 60 W per channel into 8 ohms and 90 W per channel into 4 ohms. All power ratings are continuous at 0.2 percent THD. Harmonic distortion is 0.003 percent at 1 kHz with 80 percent of rated power into 8 ohms. Input sensitivity is 600 mV RMS for 50 W into 8 ohms, and input impedance is 10 kilohms. Arcam quotes 105 dB for signal-to-noise with A-weighting. Frequency response is 20 Hz to 20 kHz within plus or minus 0.05 dB. The amplifier runs from 110 to 120 V or 220 to 240 V mains at 50 to 60 Hz. Maximum power consumption is 700 W, idle draw is 90 W and standby consumption is below 0.5 W. Arcam gives the dimensions as 433 x 325 x 105 mm, and the unit weighs 10 kg net or 11.5 kg packed.

Engineering and use context

Arcam builds the PA410 around a custom toroidal transformer and paralleled transistor output stages, housed in an acoustically damped steel enclosure with a symmetrical layout. Channels can be bridged for mono operation, and the amplifier is specified for both 4 ohm and 8 ohm loudspeaker loads. An RS232 port is included for control by automation systems, and the compact dimensions are intended for custom installation racks. There is no onboard DSP, so the unit amplifies the incoming signal without any processing stage of its own.

Pairing

As a four-channel unit the PA410 can supply surround or height channels for an Arcam AV receiver or processor, while in two-channel mode it can be driven from the outputs of a stereo preamplifier. Within the Arcam range it shares a 433 mm front panel width with the PA240, which adds an Ethernet port, switchable RCA or XLR inputs and a bridged mode.

Alternatives

For more power per channel, Arcam offers the PA240 with Class G circuitry.