Marshall Amplification JMP-1 User manual

JMP-1
Valve Midi
Pre-amp
Handbook
1
Marshall Amplification plc
Denbigh Road, Bletchley, Milton Keynes, MK1 1DQ, England
Tel: [phone]
Fax: [phone]
Web Site - http://www.marshallamps.com
Whilst the information contained herein is correct at the time of publication,
due to our policy of constant improvement and development, Marshall
Amplification plc reserve the right to alter specifications without prior notice.
Nov ‘98

Introduction
The relationship between the guitarist and amplifier has been our prime concern since the earliest
Marshall’s were produced. We always aim to give that extra edge, which can help to inspire the player,
fuelling creativity and the ability to express.
Advances in technology have allowed us to modify and enhance this basic principle for the benefit of the
musician. However, we have never lost sight of that extra emotional drive that only valves are capable of
producing. The whole character of our unique sound emanates from the breathing full bodied pure tone of
the valve.
Your JMP-1 MIDI pre-amp is a carefully designed coalescence between modern MIDI technology and
classic Marshall valve circuitry. It’s many tones are all valve generated and presented in a way that is both
comfortable and familiar to guitar players.
The digital control capabilities add a new degree of flexibility to the way in which the tones can be switched
and processed. The advantages provided by this level of control are truly astounding. After studying the
manual and with a little practical exploration, you will find an unbelievable range of sounds and will very soon
wonder how you managed without MIDI. The only limit is your own imagination.
JMP-1 Front Panel Features
1. Input Socket Connect the guitar to this socket.
2. Headphone Socket For the connection of stereo headphones.
Headphones with an impedance of 600 Ohms will give
the best performance. Connecting headphones does not
disable the outputs of the pre-amp.
3. Output Level Control Controls the volume level from the master left and right
outputs (Item 25).
4. Display The display is split into two sections and shows patch
and data information.
5. Patch Key Push this key to enter patch selection mode (0-99). The
patch key LED will illuminate to indicate patch mode.
6. Store Key Use this key to store a patch in the memory.
Operational Note:
Push once and the store key LED will flash. The data entry control (7) can now be used to change the storage location.
Pushing patch or a parameter key will abandon the store. Push the store key again to complete the store. (Also see
section Creating Your Sounds).
7. Data Entry Control This rotary control is used to increment/decrement data
information, or to select a patch in patch mode.
8. Volume Key Push this key to adjust the patch volume level between 0
and 20. The volume key LED will illuminate to indicate
that the volume parameter has been selected. The data
display will show the current value. The value can then
be adjusted using the rotary data entry control (7).
9. Gain Key Push this key to adjust the level of gain between 0 - 20.
2

10-13. Tone Control Keys These keys should be combined to shape the Bass,
Middle, Treble, and Presence tone parameters. They can
all be adjusted between -6 and +6.
14. Effect Key This key varies the mix of the stereo effects loop between
0 and 12. At 0 only the direct signal is heard and at 12
only the effected signal is heard. When at 12 the loop is
effectively running in series i.e. no direct signal. This is
ideal for use with a graphic equalizer or compressor
limiter. As the effect parameter level is reduced, more
direct signal is introduced as with a parallel loop. This is
best suited to Chorus, Delay, Reverb etc.
15. OD1 Key This key selects overdrive 1, a warm vintage drive
reminiscent of Marshall Super Lead amps through to
modern day Master Volumes.
16. OD2 Key Selects overdrive 2. This a tightly focused high gain
drive which can be smooth or aggressive depending on
the E.Q. and gain settings.
17. Bass Shift This is a subtle low frequency character control which
can be switched in or out of any sound selection.
18. Clean 1 Key Selects Clean 1, which has a full warm character and
pure vintage tone.
19. Clean 2 Key Selects Clean 2. This has a bright sparkling tone ideal for
clean picking and ringing chords.
20. MIDI-Mapping Key The mapping function enables the mapping of incoming
MIDI patch messages to internal patches and outgoing
MIDI patch numbers to external devices. (See MIDI
mapping).
21. MIDI Channel Key This key selects the MIDI Channel on which the JMP-1
transmits and receives MIDI information.
22. Power Switch On/Off switch for mains power.
Rear Panel Features
23. Emulated Outputs Left and right outputs featuring Marshall speaker
emulation. The volume level from these outputs is
controlled by the volume level parameter key (8) not by
the output level control (3).
Operational Note: Stereo Speaker Emulation.
The Marshall speaker emulation circuit is a special filter which gives a signal virtually identical in sound to a speaker
cabinet. This allows you to link directly to the PA and obtain a stunning direct sound in a live situation. In the studio it
will give a true guitar tone direct to tape.
24. Emulated Level Selection Switch Selection switch providing +4dB or -10dB output
levels on the speaker emulated outputs.
25. Master Outputs Left and right outputs for connection to a power amplifier.
3

26. Master Level Selection Switch Gives +4dB or -10dB Master output level options.
27. Effects Return Jacks Left and right jack sockets for connection from the outputs
of an external effects processor. If using a mono effects
processor the left hand return socket only should be used.
In this instance both the left and right master outputs and
speaker emulated outputs will now be working in mono.
28. Effects Level Selection Switch Provides level selection of +4dB or -10dB to match the
level of external effects processors.
29. Effects Send Jack Output for connection to the input of the external effects
processor.
30. Footswitch Socket Connection point for optional Marshall four way
footswitch to give 4 patch selection.
31. MIDI OUT Sends outgoing MIDI messages from the JMP-1.
32. MIDI THRU Sends out MIDI messages identical to those coming in
through the MIDI IN terminal.
33. MIDI IN Terminal to receive incoming MIDI messages from
external MIDI device.
When you switch on
When switching on the JMP-1, the unit will run through an initialising
process and will then default to the patch number that was selected when
the JMP-1 was last switched off (Fig1). Your JMP-1 is now ready for
action.
Creating Your Sounds
Your JMP-1 is capable of producing a vast array of different tones, stored in the 100 available patches.
The simplicity of creating and storing these sounds is a major advantage and feature of the pre-amp.
A “Patch” is a combination of all the programmable elements that you put in, therefore if all tone and
volume selections are at 0, no sound will be produced. Each patch is made up of:
(A) The channel selection i.e. OD1, OD2, Clean 1, Clean 2 & Bass Shift
(B) The individual volume, gain, tone and effects levels that you have selected.
The first step is to select a patch by pressing the patch key (5) using the rotary data control (7) to reach the
desired patch number. The next stage is to “build” your required sound, firstly by selecting the channel
OD1, OD2, Clean 1 or Clean 2 with or without bass shift, then by selecting the volume, gain, tone and
effects levels. These controls work in exactly the same way as a normal Marshall amplifier, where
increasing the gain brings in more overdrive and the tone selections interact to “shape” the sound.
The JMP-1’s controls are there to be used to the full and by experimenting with all the extremes you will
quickly understand it’s capabilities and build your own library of sounds.
4
Patch Data
Patch
Store
Fig 1 Patch

Storing Yours Sounds
When you are satisfied with the sound that you have created, storage is
achieved in the following way. Push the store key (6) once , the LED will
flash (Fig 2). Select the desired patch location using the data entry
control (7). (Pressing the patch or any parameter key will abandon the
store). Push store a second time to complete the store
Memory Lock
A memory lock can be set to keep your data safe. This will disable any
functions that write data to the internal memory i.e Store, Mapping,
Channel & System Exclusive. If the memory is locked an 'L' will appear in
the right of the display when you attempt a store (Fig 3). At this stage the
lock can be toggled on or off by pressing the Channel key.
Sound Selections
There is a definite identifiable character to the “Marshall Sound” throughout the years. largely derived
from the unique qualities of valve power. Our expertise in harnessing valve drive has been fully exploited
in the JMP-1 to recreate the various classic sounds and to generate new tones that will become the classics
of the future. Bearing in mind the variations in guitar types and styles, plus the flexibility of the control
parameters, the following guide gives an indication of each channel's basic sound type.
Clean 1
This is a warm full bodied clean tone, ideal for rich chords, which can be softened for jazz tones or, by
adding gain, will suit clean lead lines with a hint of vintage distortion.
Clean 2
In complete contrast to Clean 1, Clean 2 is bright and glassy with a clear jangling tone. In addition it
contains the unique lively “edge” found only in the early JTM 45 and Super Lead Amps operating at
volumes just below distortion.
OD1
Features the purity of distortion from the golden age of the plexi glass Super Leads. As the gain is
increased you pass through degrees of distortion into a rich higher gain mode, with just the right nuances
for the modern blues rock player. Vintage crunch, modern metal and fat blues lead sounds are all readily
available.
OD2
Tightly focused stunning high gain is what you will find in OD2. Modern and aggressive, smooth and
fluid, the gain levels and singing tone of this channel will give you infinite sustain whilst retaining a pure
toneful quality.
Bass Shift
The Bass Shift option can be switched in or out of any channel selection. When selected it thickens the
bottom end of the sound and tightens the playing feel. On clean selections it adds body and on overdrive
provides the extra low end “throb” so essential for heavy rock sounds.
5
Patch Data
Patch
Store
Patch Data
Patch
Store
Fig 2 Store
Fig 3 Memory lock Activated

Factory Sounds
Your JMP-1 has 26 sounds ready programmed into patches 00-25. These patches have been programmed
by experienced guitarists. They have also been used in full stage and studio performance. These sounds
can all be edited in the way described earlier and recalled if necessary using the procedure described in
the section-“to re-initialise the JMP-1.”
Pre set sounds
TITLE MODE B/S VOL GAIN BASS MID TREB PRES
00 Smoke-em OD 2 off 18 20 3 -3 3 1
01 Chunkus OD 1 off 17 20 1 -3 3 4
02 Sticky OD 1 on 15 13 1 2 6 3
03 Cleeeeen CL 2 off 20 9 3 -1 4 6
04 British Steel OD 2 on 17 16 4 0 4 1
05 Nasal Tone OD 2 on 16 20 0 1 6 6
06 Quo !!! OD 2 on 17 10 2 -2 6 3
07 Angus-Ho OD 2 on 17 14 0 -1 3 2
08 Filth OD 2 on 17 20 2 -6 6 6
09 Bloooz-O OD 2 on 17 11 2 -2 3 2
10 Bloooz-O+ OD 2 on 17 19 2 -2 3 2
11 Tej'as OD 1 on 16 14 1 -1 4 1
12 Modster OD 1 on 14 20 2 1 5 5
13 Biffa OD 1 off 15 20 2 0 3 3
14 More Gary OD 2 on 17 4 3 0 3 3
15 Mid-lands OD 1 on 14 17 2 6 3 3
16 Sunshine OD 2 on 15 10 1 6 -6 3
17 Britaevious CL 2 on 17 17 4 -2 6 6
18 Trash OD 1 on 17 9 4 -1 2 3
19 800's OD 1 off 16 15 6 0 3 3
20 LA Crunch OD 1 on 16 17 6 1 3 2
21 Crusher OD 1 on 18 12 5 -4 5 4
22 Grit Clean CL 2 off 16 19 3 -1 4 6
23 Shred Spread OD 1 on 17 20 5 0 6 6
24 Warm Grit CL 1 on 16 20 -1 3 6 6
25 Mellow CL 1 off 20 14 2 -2 1 1
6

Pre set sounds descriptions
TITLE MODE ATTRIBUTES PICKUPS COMMENTS
00 Smoke-em OD 2 Lots of drive & sustain It starts here
01 Chunkus OD 1 Big, Ugly & Fat Gain controls "chunkiness"
02 Sticky OD 1 Edgy grime Big change for different guitars
03 Cleeeeen CL 2 Very Lots of headroom
04 British Steel OD 2 Warm & Heavy English overdrive
05 Nasal Tone OD 2 Thin, midrangy & cutting When tracks are full, this fits
06 Quo !!! OD 2 Bright crunch Rocks you all over the world
07 Angus-Ho OD 2 Mid '70s Marshall Tone
08 Filth OD 2 Bright, semi scooped Great for chords
09 Bloooz-O OD 2 Plexi 50 Watt Classic tone
10 Bloooz-O+ OD 2 Plexi 100 Watt As above, more aggressive
11 Tej'as OD 1 Punchy/dark drive Increase gain for vintage singles
12 Modster OD 1 Mod-ed Plexi More than enough
13 Biffa OD 1 Obnoxious overdrive In your face crunch
14 More Gary OD 2 JTM 45 on "6" Started it all
15 Mid-lands OD 1 Honky mid range voice Cuts through
16 Sunshine OD 2 Cleaner than you think! Increase Treb. for dark guitars
17 Britaevious CL 2 Modern clean - Pick's up EFX well Hi output pickups will distort
18 Trash OD 1 Very broad modern tone Fills up a lot of space
19 800's OD 1 JCM800 - Deliverin' the dB's Set bass to suit your guitar
20 LA Crunch OD 1 Mod-ed JCM800 on "5" Decrease Pres. for single coils
21 Crusher OD 1 JCM900 on "8" Mid control very effective
22 Grit Clean CL 2 Clean & on the edge Hi output pickups will distort
23 Shred Spread OD 1 Full scoop shred tone Bass control is the key here
24 Warm Grit CL 1 Dark & on the edge Hi output pickups will distort
25 Mellow CL 1 Clean & pretty Roll back guitar tone for full "Jazz"
7

Some Notes On MIDI
In a modern guitar set-up you might have a number of elements, a pre-amp and an effects processor or
two. By using MIDI to link these devices together, you can control them all simultaneously. This is the real
use of MIDI for the guitarist (Musical Instrument Digital Interface). Most MIDI devices are equipped with
three MIDI terminals, MIDI IN, MIDI THRU and MIDI OUT. The connection between these terminals is quite
simple. A MIDI IN terminal would be connected to a MIDI Out or MIDI THRU terminal. Messages are sent
from a MIDI OUT terminal to a MIDI IN terminal.
MIDI messages received at the MIDI IN terminal are simultaneously routed through at the MIDI THRU
terminal. So the messages being sent via MIDI THRU are a direct copy of the messages received at
MIDI IN. The MIDI OUT terminal is not the same as the MIDI THRU terminal. The JMP-1 will send it’s own
MIDI messages via the MIDI OUT terminal.
There are various different MIDI messages that one device can send to another. The most important
message is the MIDI program (patch) change message. When the JMP-1 receives a program change
message it will call up a patch. Whenever the JMP-1 calls up a new patch it also sends a MIDI program
change message via the MIDI OUT terminal. Pressing a pedal on a MIDI foot controller will send a
MIDI program change message. Each MIDI program change message carries a number between 00 and
127 corresponding to the patch/program to be called up. The JMP-1 has 100 internal patches but will
respond to all 128 MIDI program change messages, by using a MIDI mapping table.
MIDI Channel
Another important thing to know about MIDI, is the idea of MIDI Channels. Most MIDI messages are sent
over a MIDI Channel, of which there are 16. In order for one MIDI device to communicate with another,
both devices must be operating on the same MIDI Channel.
The JMP-1 can be set to operate on any one of the 16 MIDI channels or in Omni mode. In Omni mode the
JMP-1 will respond to MIDI messages on all channels and will transmit on channel 1.
To Set The MIDI Channel: After pressing the channel key the display will indicate the current MIDI Channel
setting (Fig 4).
Use the data entry control to select channels 1 to 16 or Omni
mode. Press the channel key again to store the channel setting
and return to patch mode.
Note: The MIDI Channel setting is a ‘Global` parameter and not
stored with an individual patch. MIDI Channel setting is retained
whilst the unit is not powered.
Fig 4 Channel selection
8
Patch Data
Patch
Store

MIDI Mapping
MIDI mapping is a simple and very useful facility, but it often confuses those who are new to MIDI. The MIDI
Mapping table is stored in the memory and is made up of two parts, Input mapping and Output mapping.
Input Mapping
The input mapping table makes it possible to transpose any incoming MIDI Program Change number to
select any desired JMP-1 patch. For Example:
MIDI Program Change 124 could be mapped to JMP-1 patch 36, so whenever the JMP-1 received MIDI
Program Change 124 it would call up patch 36. The Input mapping function is invaluable if you are using
a MIDI foot controller that sends fixed Program Change messages.
Output Mapping
In the same nature as input mapping, the output mapping function can transpose any outgoing Program
Change message. If the MIDI OUT of the JMP-1 is driving an external effects processor, the JMP-1’s output
mapping can be used to select a particular effects program for each JMP-1 patch, with the advantage that
several JMP-1 patches can share the same program on the effects processor.
To Edit The Mapping Table:
1) Push Map key once to select incoming MIDI Program number. (See Fig 5). Use the data entry control to
select the incoming Program number (00 to 127). The decimal point signifies program numbers 100 and over.
2) Push again to select the Internal Patch to be called up (00 to 99) (See Fig 6).
3) Push the Map key a third time to set the outgoing MIDI Program Change message to (00 to 127) (See Fig 7).
4) Pushing the Map key a fourth time will store edits and return the JMP-1 to Patch mode.
Note: The mapping table is remembered whilst the JMP-1 is not powered.
Fig 7. Outgoing MIDI programFig 5. Input Mapping Fig 6. Internal Patch Number
9
Patch Data
Patch
Store
Patch Data
Patch
Store
Patch Data
Patch
Store
Indicates 100-127
Incoming MIDI
Data
4 Way Footswitch
(Patches 1-4)
Call up Internal
Patch (00-99)
Front Panel
Control
Output Mapping
to MIDI Device 00-127
MIDI
IN MIDI THRU MIDI OUT
Input
Mapping

Four Way Footswitch
The optional Marshall four way footswitch (model MPM 4E) provides a simple means of selecting four patches.
The footswitch will call up patches one to four, however, the Mapping facility can be used to call up any
four of the 100 JMP-1 patches.
To Re-initialise The JMP-1
This procedure will re-load the factory sounds and reset the mapping table.
WARNING:- Your edited sounds will be lost if the unit is re-initialised.
Procedure, Hold down OD1 and Clean 1 whilst switching on the power.
Memory back-up
The JMP-1 has an internal battery back-up system to keep your patches safe
while the unit is switched off. This battery should last for several years.
Every time you power up the JMP-1, a self check program is run. If any
errors are detected an "E" will be displayed momentarily (Fig 8).
If this should occur repeatedly, then it is likely that the internal back-up
battery needs replacing. Contact your dealer as soon as possible and
back up your patches (see System Exclusive).
System Exclusive
By using system exclusive MIDI code, it is possible to dump all your patch and mapping settings to an
external MIDI device such as a sequencer or data filer.
To Transmit MIDI Dump Data:-
Connect a MIDI cable from the MIDI OUT of the JMP-1 to the MIDI IN of the receiving device. Press the
PATCH key and the VOLUME key together to begin transmitting. The display will indicate that a MIDI
exclusive dump is in progress by counting the data blocks (0 thru' 9) as they are transmitted (Fig 9).
When the transmission is completed, the display will return to normal.
To Receive a System Exclusive Dump:-
Connect a MIDI cable from the MIDI OUT of the transmitting device to the MIDI IN on the JMP-1. (Ensure
that the memory lock is off - see page 6)
WARNING:- Receiving a MIDI dump will re-write all your patches and mapping data, so be sure that you are
loading the correct data before you start. If you are unsure then make a back up of your current data
beforehand.
Ex ecute the dump from the transmitting device. When the JMP-1
recognises the system exclusive code it will automatically respond by
counting the MIDI data blocks as they are successfully received (Fig 9).
If this does not happen then re-check the MIDI connections and that you
are sending the correct file. When the transmission is completed, the
display will return to normal.
Fig 9. System Exclusive Dump
10
Patch Data
Patch
Store
Patch Data
Patch
Store
Fig 8. Error Detected

If their is an error (Fig 10) in the MIDI data the JMP-1 will abandon the
load and return to normal. Try the load again, the error could be due to
a file corruption or faulty cable.
MIDI Implementation Chart
Mode 1 :OMNI ON, POLY Mode 2 :OMNI ON, MONO 0:YES
Mode 3 :OMNI ON, POLY Mode 4 :OMNI ON, MONO ✕:NO
FUNCTION TRANSMITTED RECOGNIZED REMARKS
Basic Default 1 OMNI Memorized
Channel Channel 1-16 1-16
Default ✕MODE 1
Mode Message ✕✕
Altered ✕✕
Note ✕✕
Number True Voice ✕✕
Velocity Note ON ✕✕
Note OFF ✕✕
After Key's ✕✕
Touch Channels ✕✕
Pitch Bender ✕✕
Control Change ✕✕
Program 0-127 0-127
Change True#0-99 0-99
System Exclusive 0 0 See Note
System :Song Pos ✕✕
:Song Sel ✕✕
Common :Tune
System :Clock ✕✕
Real Time :Commands ✕✕
Aux. Messages :Local ON/OFF ✕✕
:All Notes Off ✕✕
:Active Sense ✕✕
:Reset ✕✕
Notes System Exclusive Patch dump and load when Memory lock is off.
11
Patch Data
Patch
Store
Fig 10. System Exclusive error

JMP-1 Front Panel Features
JMP-1 Rear Panel Features
Patch Data
Patch
Store
VALVE MIDI PRE-AMP
JMP-1
Volume
OD1
Gain
OD2
Bass
Bass Shift
Middle
Clean 1
Treble
Clean 2
Presence
Map
Effect
Channel
Data
Output Level
Input Phones Power
Made in England
- +
MAINS INPUT
230V ~ 50/60Hz 20 Watts
Jim Marshall (Products) Ltd, England
WARNING: Fire and Shock Hazard - Do not
Expose Unit to Rain or Moisture.
Shock Hazard This Unit Must be Earthed.
Don Not Open.
AVIS: Risque de choc Electrique - Ne Pas Ouvrir
WARNING: No User Serviceable Parts Inside.
Refer to Qualified Personnel.
MIDI FOOTSWITCH EFFECTS MASTER
L. OUTPUTR. OUTPUTLEVELLEVEL L. OUTPUTL. RETURNR. RETURNLEVELSEND
+4 dB
-20 dB
OUTTHRUIN R. OUTPUT
SPEAKER EMULATOR
+4 dB
-20 dB +4 dB -20 dB
1 2 3 4 5
6
34 33 32 31 29 28 27 26 2430
15 16 17 18 19 20 21 22
8 9 10 11 12 13 147
25 23