Since the explosion of rock 'n' roll, one name has remained at the heart of its most electrifying moments: Marshall. For generations, Marshall amplifiers have defined the sound of the electric guitar, propelling music to new heights and shaping the very essence of modern rock. From the exalted blues-rock of Eric Clapton to the incandescent performances of Jimi Hendrix, through the powerful riffs of Jimmy Page, Eddie Van Halen, and Angus Young, the unmistakable roar of Marshall has been the foundation of a legendary sound.
At the heart of this legacy lies the Marshall Plexi, an amplifier so iconic that it has remained a benchmark for tone since its launch in the 1960s. Originally designed to meet the demand for increased power and volume, the Plexi offers clean, bright sounds at low volumes, but transforms gradually as you increase the volume: first toward a rich, biting saturation, then into that thick, harmonic-rich distortion that became the voice of the rock guitar. Whether it's the bluesy crunch of the late 60s, the hard rock revolution of the 70s, the high-octane shred of the 80s, or the grunge and alternative explosion of the 90s, the JMP remains the reference amp.
Today, Synergy and Marshall are partnering to offer you the ultimate tribute to this legendary amplifier. Combining Synergy's patented, cutting-edge modular technology with Marshall's historic circuit design, this new Synergy JMP preamp module delivers the unmistakable raucous sound, touch sensitivity, and dynamic response of a cranked JMP, at any volume. On stage, in the studio, or at home, this is your opportunity to master the sound that shaped rock 'n' roll. The legend continues.
A LEGENDARY SOUND IN A MODERN FORMAT
The Marshall JMP preamp module features two channels, each with Volume 1, Volume 2, and Master controls. Each channel has independent bass, middle, and treble controls, as well as a Bright switch for each volume. The JMP module incorporates two vintage switches, allowing you to choose between different classic JMP models. The 60s mode offers a rounder, smoother JMP sound, while the 70s mode offers a more precise and aggressive response, ideal for capturing the evolution of the rock sound over the decades. Both channels can be set to achieve variations on the same sound or to switch easily between a rhythm setting and a solo setting. The Volume 1 and 2 controls function like the input switches of the original Plexi, allowing for precise gain control. In addition, independent master volumes for each channel allow you to access the entire sonic palette of the Marshall Plexi, regardless of volume.
INTEGRATED PHASE INVERTER – 0 WATT POWER AMPLIFIER
Imagine a complete guitar amp integrated into a preamp module. In a traditional amplifier, the preamp sculpts the sound and provides the gain, while the power amp delivers the volume, power, and dynamics characteristic of a tube amp. To faithfully recreate this experience, the JMP module incorporates a "0 watt" power amp, with a phase inverter and small transformer. This innovative approach accurately captures the harmonic complexity and dynamics of a cranked Marshall amp, offering the sonic richness and feel of a full-size amp, all in a compact, all-tube module.
DUAL-CHANNEL TUBE PREAMP
The Marshall JMP module offers the unmistakable sound and dynamics of one of Marshall's most legendary amplifiers. Designed to recreate the raw power and harmonic complexity of the original non-master volume JMP, this module features two identical and independent channels, allowing for a wide palette of sounds, from clean and precise tones to rich, biting saturations and the most incisive distortions. The independent three-band EQ (bass, middle, treble) offers the possibility to sculpt the sound interactively, just like the original JMP. Volume 1 corresponds to the brighter input, while Volume 2 corresponds to the darker "normal" input. These controls work together to create the perfect Marshall sound, with independent master volumes on each channel for precise level balancing.
BRIGHT SWITCHES
The four bright switches allow you to adjust the bright capacitor of each volume control. Simply put, the bright capacitor of a Marshall JMP influences the amount of high frequencies (treble) passed by the volume control, making the sound brighter and more incisive. On a traditional JMP, this adjustment would require the intervention of a technician, but the JMP module allows you to customize the brightness of your Volume 1 and 2 controls. By blending both channels, you can combine the brightness of Volume 1 with the warmth of Volume 2 to get the perfect balance between attack and depth. CATHODE SELECT FUNCTION
The Marshall JMP module features a three-position switch on the circuit board, allowing you to configure the bass response of the input tube to match the original circuit of the selected module. These settings influence the feel and precision of the sound. Each amp designer has a specific combination of components that…Configure your input circuit. We have selected the three most common combinations, accessible via this switch: position 1 (1.5 kΩ resistor and 22 µF capacitor), position 2 (2.7 kΩ resistor and 0.68 µF capacitor), and position 3 (1.8 kΩ resistor and 1 µF capacitor). Feel free to test different positions to find the one that suits you best. The JMP module is preset to position 1 (1.5 kΩ resistor and 22 µF capacitor).