Усилители мощности стерео — Parasound NC 275v2

The NC 275v2 is a stereo power amp from Parasound's NewClassic range, built into a 1U chassis with a fully discrete Class AB circuit and a high-current toroidal transformer. Parasound lists it at USD 900 and grants a 2-year warranty covering parts and labour.

Key specs that matter

Rated RMS output from 20 Hz to 20 kHz with all channels driven is 90 W per channel into 8 ohm and 150 W per channel into 4 ohm, and the same 150 W per channel holds into 2 ohm once the rear load switch is set to its 2-3 ohm position. Bridged to mono, the amplifier gives 200 W into 8 ohm, or into 4 ohm with the load switch engaged. Peak current capacity is 20 A per channel. Frequency response runs from 20 Hz to 50 kHz, +0/-3 dB at 1 W. Total harmonic distortion is 0.35% at full rated output and 0.025% at average listening levels, with IM distortion at 0.05% and dynamic headroom of 1.3 dB. Signal to noise ratio is 110 dB at rated output IHF A-weighted, or 103 dB unweighted, and 93 dB A-weighted at 2.828 V output. Input impedance is 33 kOhm and input sensitivity is 800 mV for full output, equal to 28 dB of gain. Crosstalk between channels is 80 dB at 1 kHz and 65 dB at 20 kHz. Damping factor exceeds 150 at 20 Hz.

Engineering and use context

The chassis measures 437 x 406 x 63 mm with feet, 406 mm being the depth with cables connected, and the front panel itself is 44.1 mm tall. Net weight is 9.1 kg. Power draw is 0.5 W in standby, 25 W at idle and 350 W when driven to rated power, running from 110-120 V or 220-240 V mains set by a rear selector. A DC servo and relay protection circuits guard the outputs, and front lights signal standby, per-channel status and overheating. Two pairs of 24k gold-plated 5-way speaker terminals are switched by front A/B buttons, which a rear lockout switch can disable. A switchable high pass filter is fitted. The amplifier turns on by a 9-12 V DC trigger with looping output, or by signal sensing, whose threshold is selectable at 1 mV and 6 mV. Separate level trims for each channel share the rear with gold-plated RCA inputs, and a 1U rack mount kit, model RMK11, is sold separately.

Pairing

Lacking a volume control, the NC 275v2 takes its signal from a separate preamp or from a player with adjustable level. Its stability into very low loads lets it drive low impedance loudspeakers, and a pair of units bridged to mono can serve as dedicated monoblocks.

Alternatives

The Parasound NC 2125v2 is the larger NewClassic stereo amplifier, a 2U Class AB design with THX Ultra2 certification.