The One – Electric guitar pedal – 90s Marshall JMP-1 Style Overdrive, Distortion

The One is a true-bypass guitar pedal designed and built with the intent of recreating the sound of the Marshall* JMP-1 rack unit.

Exactly like other products of our line, inspired by instruments of the past, The One is not intended to be a clone or a replica, our mission is to recreate that reference sound in a normal guitar pedal to be used with the amplifier in the most traditional way possible.

Marshall JMP-1

Released in 1992 and in production until 2007, the JMP-1 unit has been used by many artists worldwide in every genre (especially rock), tracing its particular sound back to the 90s. It was a tube preamp with 4 modes (Clean 1, Clean 2, OD1 and OD2) and a complete MIDI implementation, not the first rack preamp in history with these features but certainly the first Marshall product with these characteristics, quite popular in those years.

The concept

The idea for a distortion pedal inspired by the JMP-1 dates back to 2022, after the release of the Rocker 83, designed with the same intent: to offer an iconic sound with a classic use, i.e. to place the pedal on your pedalboard using it as a normal overdrive/distortion unit, in order to make our products accessible to everyone thanks to simple and immediate use.

“A few years ago, I came across the website of a well-known historic pedal manufacturer, a giant that worked closely with the greatest among them Jimi Hendrix, on the homepage I read something that really struck me: ‘…those who can invent, do. Those who can’t invent, copy.’ Initially I found it a rather irreverent and cheeky sentence, then I thought about it and found this point of view interesting. A sentence like that pronounced by someone who wrote important pages of rock in that era of extreme music growth and development is more than understandable, nowadays, things are completely different and, much more than the research for an invention, it is necessary to reinvent oneselves. With The One I wanted to pay tribute to the guitar tone that weaned my teenage dreams, offering the possibility to insert it into a standard pedalboard in a completely analog way.” – Luca Colombo

Structure and controls

The One’s original true-bypass circuitry aims to achieve that famous Marshall tone through a hybrid structure (op-amp and jfet) in order to recreate the typical reference sound, thanks to the operational technology (as in the JMP-1) and to the jfet stage is designed to obtaining dynamics and response with typical tube characteristics.

The One needs to be considered an overdrive/distortion pedal to be used with the amplifier as you would do with any pedal of this category, when the unit is turned off it enters in true-bypass mode. There are two different types of distortion available: Lead 1 and Lead 2. When the unit is set to Lead 1 you get the typical Marshall-oriented sounds, with the mid frequencies positioned around 800hz and an overall sound rather warm and sharp. The Lead 2 mode features more air and pronounced vocal tone, suitable for solo use, it’s also excellent for modern aggressive rhythm styles.

The Tone control is designed to provide a true tone stack in a more compact format: if positioned halfway it is like having an equalizer with all the controls at noon, by raising this control clockwise, up to a certain point only the high frequencies (treble) are increased without affecting the low frequencies, only towards the end of the potentiometer run the low frequencies get reduced; vice versa, by lowering the Tone control below halfway, in the first range the low frequencies are not affected and only the high frequencies are rolled-off, only when the control is in the first quarter the low frequencies increased (in addition to further reducing the high frequencies). This particular system allows you to obtain many more nuances of equalization compared to a normal tone control.

The Middle control is essential to set the type of sound you want to achieve, just like on the JMP-1, the mid-range does most of the job here: leaving the Middle control at noon ensures a neutral sound with no boost or cut on the mid-range; lower this control for a scooped and metallic sound, raising Middle over halfway instead, it fattens up the mid-range for a more present and swollen tone. The Middle control also works significantly differently depending on the mode selected, using Lead 1 mode the mids are at 800hz, if Lead 2 mode is selected the mids are moved to around 1000hz.

The remaining controls (Gain and Volume) are pretty much standard: Gain works on the amount of distortion and Volume controls the overall output level.

To recap:

• Mode: Lead 1 / Lead 2 – Lead 1 for a warm and sharp sound, Lead 2 for throaty and airy sound;
• Tone: work on the distortion equalization, it’s recommended to start by setting it at noon and lower it to obtain a darker sound or raise it to obtain a brighter sound;
• Middle: essential to sculpting your tone, it’s always recommended to start with this control halfway and reduce it for a more scooped and metal-oriented sound, increase it for a more present and on-face sound;
• Gain: sets the amount of distortion, this is a hi-gain pedal so there’s always more than enough distortion for any style or genre;
• Volume: sets the overall level, for standard use it’s recommended to balance the volume with this control with the level of our true-bypass sound (effect off).

*Colombo Audio Electronics is in no way affiliated with Marshall Amplification or its products. The above brand name is used for reference purposes only.