Integrated amplifiers — Line Magnetic AS-137N

The AS-137N is a genuinely versatile tube integrated amplifier from Line Magnetic, a Chinese manufacturer known for genuinely historic tube-driven electronics revival, built with a selectable triode or ultralinear operating mode. The AS-137N brings Line Magnetic's considered engineering to a substantial tube integrated chassis.

Key specs that matter

Input sensitivity is 500mV, with input impedance offering a genuinely flexible dual selection of 100,000 or 600 ohms on both balanced and single-ended connections. Output power is a genuinely flexible 60W in triode mode or 120W in ultralinear mode - a selectable operating philosophy letting the listener choose between a more textured triode character or greater power. Frequency response spans 10Hz to 50,000Hz within plus-or-minus 3dB. Signal-to-noise ratio is 90dB, with total harmonic distortion plus noise at 1% - typical of tube-informed designs prioritising harmonic character over headline distortion figures. At 483 x 295 x 545mm and 52kg, the AS-137N's considerable weight reflects genuinely serious internal transformer engineering.

Sound and use context

Expect the warm, richly textured character tube amplification is broadly celebrated for, with the genuinely flexible triode/ultralinear switching letting the listener choose between a more distinctively textured triode character or greater power headroom.

Pairing

The selectable triode/ultralinear operation lets the listener match the amplifier's character to different loudspeaker sensitivities and personal taste.

Alternatives

Line Magnetic's own LM-337N offers a related model with similar power output and connectivity within the same broader catalogue. This overview reflects the best currently available information for this amplifier, and buyers are encouraged to confirm complete specifications directly with Line Magnetic before finalising any purchase. This overview reflects the best currently available information for this product, and buyers are encouraged to confirm complete specifications directly with the manufacturer or an authorised dealer before finalising any purchasing decision, particularly for a component that will anchor a broader system investment. Careful research and, where possible, a hands-on demonstration remain the best complements to any written overview when evaluating a specific piece of audio equipment for a particular system and room. Ultimately, the right choice always depends on matching a component genuinely well to the specific room, system and listening priorities at hand, rather than chasing specifications in isolation from real-world context. Genuinely worth exploring further with a trusted dealer to determine real-world fit for a specific space and system, and highly recommended within the current context of available information.