Marshall JMP1

The Marshall JMP-1 MIDI Valve Preamp is one of the most iconic guitar preamplifiers of the 1990s. Released in 1992, it represents a period when Marshall sought to combine the classic sound of its British amplifiers with the flexibility of professional rack-mount systems. Its key feature is the inclusion of four preamplification modes, programmable controls, two ECC83 (12AX7) vacuum tubes, and MIDI control, allowing for seamless switching between clean tones, crunch, and high-gain distortion. The JMP-1 became particularly associated with the sound of arena rock, hard rock, fusion, and the work of studio guitarists throughout the 1990s.