Marshall JMP-1 PREAMPS


I've used Marshall JMP-1 preamps since the 90's, and now own several. I think they're superb. The overdrive tones, especially OD1, are just brilliant for cutting through in a live mix. I can route all my effects into it, and control it via. MIDI. It has never let me down!

■  Marshall's very own Phil Wells explained to me at length showing me the circuit diagram, how the overdrive is generated, much like the Jubilee valve heads where the overdrive is hybrid generated from both the circuitry and valves.

Sadly, due to a change in the EU solder laws around the turn of the millenium, Marshall ceased production of these preamps, so I like to keep a few JMP-1's, as they're no longer made by the moment!


I go direct to the desk for all my solo gigs, regardless of the size of the event. I've played in front of 30 people, and 5,000 using the exact same JMP-1, and it just sounds great! 

The Marshall Speaker Simulator circuitry does a great job of giving me a useable tone. It's very dynamic, and responds well to my picking hand.
I use the JMP-1 direct to desk, for all my Friday and Saturday Night Rock Shows!

It's well known I am called 'OD1-Kenobi' because of my love for the OD-1 overdrive setting on the JMP-1.

One of my 1978 Marshall Master Volumes (1978)


For band gigs where I want to feel a bit more flap between my legs, I run my live rack into one or two of my old 70's Marshall amp heads via. custom power amp input mods done by Phil Wells at Marshall.

I own several vintage 70's 100w Marshall heads (2203's). Some have been modded in the past by my good friend Tony Parsons, a wizard with technical electronics! Others have been rewired by Marshall back to stock. Fitted with EL34's and 12AX7s, these amps don't mess about! 

Over the years, I've owned SLO100's, Dual Rectifiers, Boogies, Trace Elliot, Musicman, Orange,  even, at one stage a Hi-Watt, but for me, nothing beats a Marshall. 

I mainly use these either stock with my pedalboard in the front end, or with the JMP-1/Alesis 2U rack going into custom power amp input mods on the back of the heads. 
I've had these cranked once or twice, and they sound superb! 
Nowadays, It's rare for me to go out and use these, but if it's a band dep gig then it comes in handy!
They're usually so loud for me nowaday's that I much prefer the JMP-1's direct to desk, or using the Palmer PDI-03 as load boxes. I can then feed a Line Out signal to the studio, or PA/FOH. 


I prefer Marshall 4x12" speaker cabinets for large band work, but nowadays, it's mostly not needed.
Speakers are always Celestion Vintage 30's, but i also like Celestion 25-watt "greenbacks" too. 

I have plans to make two custom 2x12" cabinets and mount those inside for a stereo live rig.  When, or shoud that be, if!, gigs return!


An Alesis Midiverb IV adds Delays (435ms) for lead sounds. I love digital delay, but don't use reverb so much as it tends to push the sound back, whereas delay keeps the original signal up front. I do, however, use Reverb on Clean tones along with Chorus.

For studio recording, I love to record in stereo. I take both outs from the JMP-1 and feed them into my DAW directly.
Live I run my rig in Mono.  I see no point in running my guitar rig in stereo unless everybody stands in the sweet spot all night! By running in Mono everyone can hear the exact same sound wherever they're standing or sitting.  Good enough for Wembley and the O2, so good enough for me! 


435ms is my main delay time.
I find it works well for the widest range of purposes. 

I only use 4 main presets...

1 | Rhythm
FX - No effects
Mix - N/A
Amp - OD1 | Vol 17 | Gain 18
EQ - Bass 4 | Mid 0 | Treb 1 | Pres 0 

2 | Lead 1
FX - Mono/StereoDelay 435ms 
Mix - 4 (out of 12)
Amp - OD1 | Vol 18 | Gain 19
EQ - Bass 4 | Mid 0 | Treb 1 | Pres 0

3 | Lead 2
FX - Mono/StereoDelay 435ms
Mix - 5 (out of 12)
Amp - OD1 | Vol 18 | Gain 19
EQ - Bass 4 | Mid 0 | Treb 1 Pres 0 

4 | Clean
FX - Reverb (1.6 secs), Chorus (30% mix) 
Mix -  6 (out of 12)
Amp - Clean 2 | Vol 20 | Gain 17
EQ - Bass 2 | Mid -3 | Treb 2 | Pres 2

I still use the MPM-4E footswitch to control the JMP-1/Effects.  I'm asked frequently what settings I use, but I really only use 4 main tones...


A Palmer PDI-03 is used for the valve amps when recording, or when using a Wet/Dry/Wet Rig setup, which these days is rare.

Nowadays, I mostly use the PDI-03 for visiting artists valve heads, and I much prefer using Amplitube in the studio, or a stock JMP-1 direct to desk.

Two backup JMP-1's and a JFX-1 sit below my studio rack just in case I need them.

As of July 2023, I now use Fractal AxeFX gear for all my studio/session/live streaming and for live gigs I still use the JMP-1 setup direct to desk. 
Over time as I get more fractal gear,  i will eventually replace the JMP-1's with AxeFx gear across the board.