Marshall

JMP-1 MIDI Valve Preamp – 1992

This JMP-1 has just been fully serviced by our ex-Marshall tech, so is ready to use. It's currently set to 240v but we can change to 115v if required.

A true classic from the early ‘90s, the Marshall JMP-1 is one of the most iconic rackmount preamps ever produced. Blending genuine valve tone with full MIDI control, the JMP-1 became a staple in professional touring and studio rigs throughout the decade – and for good reason.

This 1992 example features the sought-after early production spec and delivers everything from pristine cleans through to classic Marshall crunch and saturated high-gain tones. At its core are two ECC83 (12AX7) valves, providing authentic tube warmth, dynamics and harmonic richness that set it apart from fully solid-state rack gear of the era.

The JMP-1 offers four main modes – Clean 1, Clean 2, OD1 and OD2, covering a wide tonal range. The clean channels deliver clarity and sparkle, while OD1 captures classic Marshall crunch tones. OD2 pushes things further into higher gain territory, perfect for lead work and heavier styles.

What really sets the JMP-1 apart is its fully programmable MIDI capability, allowing you to store and recall up to 100 presets. Each preset can control gain, EQ, channel selection, effects loop and output levels, making it ideal for complex live rigs or studio setups. The built-in speaker-emulated outputs also make it a great direct recording solution.

The programmable EQ section (Bass, Middle, Treble, Presence) and output controls allow for precise tonal shaping, while the stereo outputs and effects loop make integration with rack effects and power amps straightforward.

Condition-wise, this unit is in very good overall condition for its age, showing only light cosmetic wear consistent with use. Fully functional and ready to drop into a rack setup.

Key Features

• Early 1992 production
• 2 × ECC83 (12AX7) valves
• 4 modes: Clean 1, Clean 2, OD1, OD2
• 100 programmable MIDI presets
• Programmable EQ (Bass, Middle, Treble, Presence)
• Stereo outputs + speaker-emulated line outs
• Effects loop
• Rackmount 1U format
• Made in England

A cornerstone of ‘90s rack rigs used by countless touring players, the JMP-1 remains a hugely versatile and great-sounding valve preamp that still holds its own today. Perfect for anyone building a classic rack system or looking for authentic Marshall tones with modern flexibility.

Worldwide shipping available. Professionally packed and fully insured.

All of our amps are shipped in custom made Overdrive boxes with extra protection inside. We usually use UPS for international shipments. We have lots of experience shipping Marshall items worldwide and ship to North America and Europe on a weekly basis.

We are proud to be an Authorised Marshall Retailer, with shipping available across the UK and all of Europe for new gear and worldwide shipping for our used items. We also have a dedicated showroom where you can experience and test the amps in person.