Locomotive Audio 40AM-2

Locomotive Audio 40AM-2 is a two-channel, standalone version of the 40AM-1 circuit in its own rack chassis, not a pair of 500-series modules, two independent channels of octal tube electronics built into a single, mains-powered unit. It's the two-channel counterpart to the single-channel 40AM-1 module from the same octal Locomotive preamp family.

Twice the same heavy American character

Each channel repeats the 40AM-1 design: two 6SJ7 tubes (pentode input, triode output) and a maximum gain of 52dB, built on the same topology combining the RCA BA-11A and Gates SA-70 from 1940s American broadcast radio. MuMetal input transformers and nickel-and-steel output transformers, wound in-house, are shared across both channels.

A dedicated line input with no phantom power risk

Each channel gets its own 5-position Response switch, 5-position mic/line input switch, -20dB pad, 85Hz high-pass filter and high-impedance front-panel DI input. A separate line-level XLR input lets you send a line signal in "around" the mic circuit, with no risk of accidentally applying phantom power to a sensitive source. Two channels of the same octal electronics in one unit make stereo tracking or parallel-doubling a track with the same dense tonal character straightforward.

KEY FEATURES

• 2-channel octal tube preamp, standalone rack chassis
• Two independent 40AM-1 circuits in one unit
• Tubes: 2x 6SJ7 per channel
• Maximum gain: 52dB per channel
• 5-position Response switch per channel
• Dedicated line XLR input with no phantom power risk
• -20dB pad and 85Hz high-pass filter per channel
• Hand-built in the USA

TECHNICAL SPECIFICATIONS

• Type: 2-channel octal tube preamp
• Tubes: 2x 6SJ7 per channel
• Maximum gain: 52dB per channel
• Transformers: MuMetal input, nickel-and-steel output, in-house wound
• Pad: -20dB per channel
• High-pass filter: 85Hz per channel