Интегральные усилители — Line Magnetic AS-128 212

The AS-128 212 is a Class A monoblock integrated amplifier in the Analog series of Line Magnetic, the valve specialist started in 2005 by two brothers who began by restoring and copying vintage Western Electric, Altec and Jensen hardware. Each chassis handles one channel around a single 212 transmitting triode, so a stereo setup calls for a pair, with each one carrying its own preamplifier stage rather than a passive volume control ahead of the power section.

Key specs that matter

Rated output is 30 W RMS per unit, taken from speaker taps for 4, 8 and 16 ohm loads. Line Magnetic quotes an input sensitivity of 500 mV, input impedance figures of 100 kohm and 600 ohm, and a selectable gain of 40 or 52 dB. Frequency response runs from 10 Hz to 45 kHz within 2 dB, signal to noise ratio is 88 dB and total harmonic distortion is 1 percent. The valve line-up per chassis is two 12AX7, one 6L6, one 212 and two 5U4 rectifiers. Every unit measures 490 x 400 x 600 mm, weighs 70 kg and draws 1.4 A from a 220 V mains supply held within 5 percent at 50 Hz.

Engineering and use context

All wiring inside is done by hand in point-to-point fashion. A replica of the Western Electric 618 input transformer feeds the preamplifier stage, where the 12AX7 pair provides two gain steps, and the 6L6 sits between that stage and the single 212 output valve. Separate transformers supply the high and low voltages, and each unit therefore has two mains inlets, a black one for the high-voltage side and a grey one for the low-voltage side. A front mode switch changes the role between integrated amplifier and power amplifier, so the built-in preamp can be bypassed when an external control unit is preferred. The front panel also holds an ammeter, a volume knob, an input selector and the power switch, while two side switches handle the lighting and the status indicator. One balanced input and four RCA inputs are offered on each chassis, and a remote handset, two spare fuses and a detachable mains cord are packed with it.

Pairing

The single-ended output points toward efficient loudspeakers, while the highest tap covers high-impedance designs. A pair of heavy units with separate mains cables needs floor space and careful handling, and the higher gain setting gives headroom with low-output sources.

Alternatives

The AS-125PP 211 from the same Analog series is a Class AB monoblock integrated design rated at 60 W with two 211 output valves per chassis.