Усилители мощности стерео — Naim NAP 250

The NAP 250 is a stereo power amplifier from Naim Audio in the 200 Series of the company's New Classic range, designed and developed by its engineers in Salisbury, and a model name Naim has used since the first version appeared in 1975, two years after the company itself was launched in 1973. The current unit is the sixth generation of the design and shares its series with the NSC 222 streaming preamplifier and the NPX 300 power supply. Naim describes it as a class AB amplifier running from its DR regulated power supply technology, with output transistors of the NA009 type first developed for the Statement system.

Key specs that matter

Rated output is 100 W per channel into 8 ohm at 0.1% THD+N. THD+N at two thirds of full power into 8 ohm at 1 kHz is 0.013%, the damping factor into 8 ohm is 36, and crosstalk is 60 dB. Gain is 29 dB, and the amplifier reaches clipping with an input of 1 V RMS. It measures 432 mm wide, 91.5 mm high and 317.5 mm deep and weighs 16.8 kg.

Engineering and use context

Inputs are two true balanced XLR connections with a 47 kohm impedance, and a legacy adaptor allows single-ended sources to be connected. Naim builds the chassis from thick aluminium plates, which the company says limit the effects of magnetic fields, unstable temperatures and vibration on the circuit. Heat sinks inside the black aluminium alloy casing handle the thermal load together with a variable-speed fan offering seven speed settings. An eddy current slot between the speaker outputs is a detail carried over from the Statement. The mains supply can be set for 115 V or 230 V at 50 or 60 Hz. Power draw is 26 W in normal use, below 0.5 W in standby and below 0.3 W when switched off. The box contains a Power-Line Lite mains lead, two XLR to XLR balanced interconnects and an optical system automation cable, so the amplifier can be linked into a Naim system without buying extra leads.

Pairing

Naim names the NSC 222 preamplifier and streamer as a match, and the NAP 250 also works with other New Classic products as well as the earlier Classic lines. With balanced XLR inputs, it suits a preamplifier with balanced outputs, and the supplied pair of XLR leads covers both channels of such a connection.

Alternatives

The Naim NAP 300 DR uses a two-box stereo layout that places its power supply in a separate 300 PS unit and uses the same NA009 transistors.