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Marshall JMP-1 Preamp

Posted by on December 25, 2015

The Marshall JMP-1 rack mounted pre-amp was first introduced my marshall in the year 1992. Is this value driven Marshall JMP-1 the best pre-amp ever? Some people might doubt that, but after 20+ years of playing guitar, I am convinced this is the most versatile pre-amp in the business. And… it’s a simple one.

Marshall JMP-1

Marshall JMP-1

There are many (combined) pre-amps available. but not as great as the JMP-1. 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)

Here is the original Marshall JMP-1 Handbook

In my opinion, the best way to use this pre-amp is with a Marshall 9200 dual mono block power amp and a Marshall JFX-1.

Marshall JFX-1.jpg

Marshall JFX-1.jpg

I managed to find the original brochure-poster of the JMP-1. I thought it is awesome.

JMP-1 poster JMP-1 poster


Marshall 9200

Marshall 9200

I will do my best to write a review on these two suckers too. They are the favourite setup of Dave Murray of Iron Maiden and of Billy Gibbons of ZZ-Top. Here are some nice reviews on youtube:

This is a picture of the original catalog

Marshall Rack products

Marshall Rack products

I use the Marshall JMP-1 in combination with the Digitech Control Seven, and not with the limited 4-switch marshall control pedal. The Control Seven gives more control combinations and is a compact and robust pedal.


Digitech Control Seven

Digitech Control Seven

So, what is my verdict? This pre-amp gives me any tone I would like to create, from blues, clear rock to rock, heavy metal or death metal. And what is the best option with this pre-amp: you have over 100 channels you can pre-program. Many guitarists use boost-pedals to get their volume up for a solo (for example in a 2 guitarist band). This pre-amp lets you configure as many volume stepped channels as you need. I personally only have 10 presets, or maybe one or 2 more. But you *could* even configure a preset bank (so:1 clean, 1 rhythm, 1 lead, 1 solo, 1 other) per guitar. If you have 10 guitars, it will take you some time though. I have tried a number of amps, including a silver jubilee, but have recently concluded that the JMP-1, JFX-1 and the 9200 is my go-to configuration.

Some interesting resources for all the JMP-1 lovers:

Here is a link to the on line JMP-1 Patch Editor.

Here is the link to the JMP-1 modification page at Voodoo amps.

Here is the link to the Marshall JMP -1 users tips,tricks & patches page on Facebook

Here is the link to the Marshall JMP-1 page on Facebook

Here is the link to the SoundQuest Marshall JMP-1 Librarian

Which artists do I know of that use or have used a JMP-1?

  • Dave Murray (Iron Maiden)
  • Mick Thompson (Slipknot)
  • Vivian Campbell (Def Leppard)
  • Phil Collen (Def Leppard)
  • Billy F. Gibbons (ZZ Top)
  • Jannick Gers (Iron Maiden)

Recently I have also started a Facebook page for the JMP-1 called “the Marshall JMP-1”. Check it out here



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