Предусилители — Line Magnetic LM-1126 + 20B

The LM-1126 + 20B is a two-chassis valve design from the Line Magnetic catalogue, whose founders set up the firm in 2005 as two brothers whose early work was repair and replica building of old WE, Altec and Jensen hardware. Its circuit starts from the Western Electric 1126, originally a dynamic compressor for recording and broadcast studios. Line Magnetic reworked that circuit into what it calls a dynamic expanding preamplifier, intended to restore signal from LP, CD and radio sources, and the 20B is its separate power supply unit.

Key specs that matter

Gain is quoted at 11 dB and input impedance at 600 Ohm, a low value compared with the 100 kOhm used on several other Line Magnetic preamplifiers. Frequency response runs from 20 Hz to 20 kHz, measured at 1 W. The main unit is 440 mm wide, 260 mm high and 500 mm deep, and it weighs 22 kg net. Connections include an RCA line input and an XLR line input, and the box contains a handset, a detachable mains lead and a pair of spare fuses. A reference price of USD 9,562 has been listed for the standard version.

Engineering and use context

The audio chassis carries sixteen valves - four 6L7, four 6J7, four 6J5, two 6SL7 and two 6H6. The 20B supply adds a 300B, a 5U4, a 313, a 6J7 and a 6X5, so the power section alone holds five tubes and the complete preamplifier uses twenty-one. On the input side the maker fits a Western Electric 618B transformer, the signal path includes a RET-D159807 balanced choke, and the output stage uses a WE 171B transformer together with dedicated 1126 parts. The output transformers belong to the WE series. The brand says it wires each unit by hand, point to point, across its two production sites.

Pairing

As the input impedance is low, the source needs an output stage able to drive that load. Owners need shelf space for two boxes and a link cable between them. The remote handset handles volume from the seat, and a Line Magnetic power amplifier based on 300B, 805 or KT88 tubes keeps the chain within the same brand.

Alternatives

A smaller option from Line Magnetic is the LM-44 preamplifier, a Western Electric 44 based design with 101D and 205D tubes, 10 dB gain and a 100 kOhm input.