AGD (Alberto Guerra Designs) Gran Vivace MKIII Monoblock Amplifiers - Hybrid Magic!

A Personal Note on the AGD Gran Vivace MKIV from company owner, Alberto Guerra

"From the very beginning, my goal has been simple: to bring together perfection and beauty in the art of audio reproduction. Every AGD design is a continuation of that pursuit—an ongoing dialogue between technology and music.

The AGD GaNTube™ platform reflects this journey. Now in its fourth generation since its introduction in 2020, the new GaNTube120KT MKIII represents a meaningful step forward. At its core is a new generation of high-voltage GaN HEMT devices, combined with refined thermal management and an improved low-noise linear regulator stage—each element carefully engineered to elevate performance without compromising musical integrity.

The Gran Vivace MKIII delivers an even deeper sense of control and authority when compared to other "similar" amplifiers. The latest GaNTube implementation, together with a newly developed 100% GaN-based power supply—capable of delivering up to 6kW peak power—allows the MKIV to respond with remarkable speed and composure, even under the most demanding conditions.

The result is a greater clarity, lower distortion, and a more effortless presentation. Music unfolds with enhanced transparency and dynamic precision, revealing nuance and space with a natural, unforced quality and holographic imaging that define the AGD sound.

Every detail has been considered to preserve what matters most: a sense of realism, emotional connection, and ease, while at the same time, the Gran Vivace MKIV retains the elegance, simplicity, and upgradeability that define the AGD philosophy."

-Alberto Guerra

Evolution of Speed, Control, and Musical Truth

The Gran Vivace platform has always occupied a unique position in high-end amplification,  not  simply as a powerful Class-D design, but as a deliberate rethinking of how modern power electronics can serve music.

With the Gran Vivace MKIII, that philosophy reaches a new level of maturity, where engineering refinement and sonic expression converge more seamlessly than ever before. At the heart of the Gran Vivace architecture lies AGD’s distinctive GaNTube™ platform, a modular approach that integrates the entire power stage into a compact glass enclosure. This is not merely an aesthetic gesture; it is a deliberate engineering choice aimed at maintaining consistency across revisions and delivering unprecedented easy of upgrade.

Earlier generations of the Gran Vivace (and Audion) already demonstrated the advantages of GaN (Gallium Nitride) switching devices and the Gran Vivace MKIII builds upon this foundation with a new generation high-voltage GaN HEMT MOSFETs, new PCB layout optimized for speed and thermal efficiency, and improved device integration and high-reliability components.

The system continues to operate at ~800 kHz PWM switching frequency, a regime that pushes switching artifacts well beyond the audible band and allows for a more benign output filtering process.