Усилители мощности стерео — Luxman M-200

Luxman's M-200 is a two-channel power amplifier built into a B4 size case measuring 364 x 81 x 297 mm and weighing 7 kg. It uses a discrete construction with high performance parts shared with Luxman's 500 series integrated amplifiers, and the output stage relies on large capacity PC150W power transistors in push-pull. A bridged mono mode is available, and the case has an aluminium front panel and sits on vibration-isolating feet. It shares its B4 footprint with Luxman's DA-200 USB DAC, and Luxman presents it for desktop systems fed from a computer as well as for conventional hi-fi. The US list price was USD 2,000.

Key specs that matter

Rated output is 25 W per channel into 8 ohm and 35 W per channel into 4 ohm in stereo, or 70 W into 8 ohm in BTL mono, which Luxman suggests for lower impedance speakers or large floorstanding models. Gain is 23 dB in stereo and 29 dB in BTL mono, and 1.0 V of input produces full output into 8 ohm. Input impedance is 16k ohm on the RCA line input and 33k ohm on the balanced input. Frequency response is 20 Hz to 20 kHz within 0.2 dB and 10 Hz to 100 kHz within 3 dB. Total harmonic distortion is 0.005% at 1 kHz and 25 W into 8 ohm, and 0.06% from 20 Hz to 20 kHz at 12.5 W. The S/N ratio is 107 dB or better via RCA and 102 dB or better via XLR, and the damping factor is 100.

Engineering and use context

Luxman supplies a JPA-10000 mains cable. Its regulated supply combines a 160 VA EI type transformer made by Bando, two 5,200 uF capacitors and Schottky barrier diodes from Nihon Inter for rectification. Circuit boards use non-angled tracing and custom components, and the case avoids ground loops, which is intended to reduce the effect of ground impedance. Parallel-connected low resistance relays sit in the speaker path. Two display windows with 7-segment LEDs show output as a power meter with a hold time of 1, 3 or 5 seconds, and brightness can be set in three steps or switched off. Power consumption is 85 W in use and 32 W at idle.

Pairing

The XLR inputs include a phase inversion switch, and the 18 mm spaced RCA sockets accept large plugs. Two pairs of speaker outputs use in-line terminals for Y-lugs and banana plugs. The meter can be set for 8, 6 or 4 ohm loads, and a variable input mode bypasses the volume control when a separate preamplifier handles level.

Alternatives

The Luxman M-10X is a larger stereo power amplifier with LIFES feedback, a partial class A output stage and a higher rated output.