The ultimate in valve tone and guitarist-friendly MIDI technology comes from Marshall in the form of the JMP-1 stereo valve preamp.

The JMP-1 has the ability to store sounds, programmed from the two clean or two overdrive channel selections, in any of its 100 patch locations each of which are MIDI mappable and MIDI selectable. Compatibility with rack effects processors is ensured by the provision of level selection on the programmable effects loop. In addition, built-in speaker emulation gives the facility of linking directly to the PA or recording desk for the most massive direct sounds imaginable.


  • OD-1/Classic Overdrive channel – smoldering power will take you from a Super Lead Plexi’s molten gold through to searing modern metal.
  • OD-2/Modern Hi-Gain channel – tightly focused high gain drive by the truckload. Modern and aggressive, yet fluid and toneful, this stunning channel will give you all the distortion and sustain you’ll ever need.
  • Clean 1/Warm, Clean channel – for warm, full bodied chords, fat clean lead passages and jazz tones.
  • Clean 2/Bright, Clean channel – has the glassy edge of a JTM45 and will give all of the bright, jangly tones you could wish for.
  • Each channel includes the following programmable controls: Volume and Gain (0 to 20), Bass, Middle, Treble and presence (rainging from -6 to +6). A Bass Shift option re-shapes the low end character of each channel, too.
  • Stereo Effect Loop is 100% programmable from 0 (fully dry) to 12 (full effects) and has level selection (-10dB or +4d) to match your effects processor.
  • Each channel and parameter selection is made by pushing the relevant key and then adjusted by using the rotary Master Data control. Once you’ve dialed in a sound you want to savem simply press the Store Key twice. Recall is instant either from the front panel, via the optional Marshall 4 way footswitch (MPM4E), or via MIDI.
  • The JMP-1 has MIDI IN, OUT, and THRU connections plus a mapping facility. You can also select the channel (1-16/Omni) on which MIDI messages are transmitted and received by the JMP-1.
  • Left and Right Outputs are switchable between -10dB and +4dB.
  • Also features Speaker Emulated Outputs.
  • Dimensions: 1 U Rack (260mm depth)
  • Weight (Kg): 4.5
  • Preamp Valves: 2 x ECC83 (12AX7A)
  • Footpedal: MPM4E (optional)