SYNERGY OS – INTERCHANGEABLE PRE-AMP
In the world of guitar amps, there exists one legendary designer and brand that very few ever get to meet, see, or play through. This is Alexander “Howard” Dumble and his namesake, Dumble amplifiers. Normally reserved to the paragon of players, you’ll find his amplifiers backing up such artists as Carlos Santana, Robben Ford, and even the late, great Stevie Ray Vaughan.

No two Dumbles are the same, but it’s the Dumble Overdrive Special that continues to reign as the man’s pinnacle design. The amplifier boasts unique sound and feel that is praised for its ability to enhance and uncover every nuance of a player’s technique and tone. And it’s this ability that has earned the amp a reputation for being one of the finest and most expensive ever made.

Yet, because these mythical amps are extremely hard to come by, we created the Synergy OS preamp module, our tribute to its iconic sound. The OS module packs the Dumble personality and user experience in a compact format, providing affordability and convenience that the original can never match.

Across the front panel, the OS features the same basic controls as the Overdrive Special amplifier. Dual footswitchable channels enable switching between the unique Dumble clean with its mid-forward clarity to the fabled smooth, singing sustain that gives the Overdrive Special its name. You’ll also find Bright and Deep, along with and Rock/Jazz switches that - along with a 3-band EQ - tailor your tone while always retaining the Dumble character. Finally, a master presence control adds just the right amount of clarity to the preamp module’s OD mode.

There’s nothing that sounds or feels exactly like a Dumble. But with the Synergy OS preamp module, you can possess the essence of one of the finest amps in the world alongside all of the other classic tones available from the Synergy system. 

CATHODE SELECT SWITCH:
This three-position switch allows you to configure the input tube bass response to match the original circuit of the selected module. This will affect the feel and tightness. Each amp designer has a specific combination of components that make up their input tube circuit. We have selected the three most popular combinations which you can access with this switch. You can experiment and try any of the positions to see what you prefer.