AGD Vivace MKii Monoblock
Design Philosophy
The AGD Vivace MKii Monoblock, is the most advanced Hi-End Power Amplifier in the market. First to use the unique GaNTube™ technology with Gallium Nitride Power-Stage integrated in a Vacuum Tube. The Gallium nitride components are the key to the reference level performance of the AGD Vivace Monoblocks.
To achieve the highest-performance in audio reproduction, switching topologies must achieve nearly ideal switching waveforms, completely oscillation-free, to minimize distortion but most importantly, to preserve the harmonic content present in the original input signal and avoid the superimposition of any additional artifacts that alter the overall spectrum and the spatiality of the music reproduction. The Gallium Nitride power MOSFETS used in the GaNTubeTM power stage, simplifies this challenge through its ability to efficiently switch at much higher slew rates than any silicon based power MOSFET, with almost perfect (book-like) behavior and oscillation free switching.

Design Philosophy
With the seamless ability to drive any loudspeakers, 200W of power, 48,000µF of super audio grade capacitor reservoir, and the fastest slew-rate, the GaNTube™ Technology delivers the purest sonic experience.
Thanks to the Gallium-Nitride power stage intrinsic characteristics, the virtually stray-inductance free package, and a state of the art layout of the power module, the rise time and fall time of the Vivace’s GaNTubeTM power stage are fully symmetrical at ~15ns. The output waveform at the switching node of the Gallium-Nitride power stage (pre-LC filter) is completely oscillation free even with a slew rate of 3700V/µs!
This oscilloscope snap-shot of the output power stage half-bridge switching node, is a dramatic evidence of the tremendous difference in switching speed between the Gallium Nitride Power MOSFET and the state of the art Silicon Power MOSFET equivalent.
The combination of low noise design technique implemented and the best practice for the internal board layout, the RF quality BNC connectors for the analog signals, are the key contributors of the excellent noise floor of the Vivace Monoblocks and extremely low distortion.

AGD Vivace MKii Monoblock Power Amplifier
” The “Vivace” Monoblock is a unique blend of avant-garde industrial design, and leading edge power electronics into a superb Hi-End Audio amplifier that delivers an unprecedented sublime and incredible realistic audio reproduction experience “.
Main Features & Characteristics
- Single Channel Class-D Amplifier
- Fully integrated in Glass Tube Enclosure
- Gallium Nitride MOSFET Power Stage
- Up to 250W 4Ω
- 800kHz PWM
- ≥ 94% Efficiency
- Noise floor at ≤ -130db
- Fully protected (OVT, OVC, DC protection)
The amps can be feed balanced or through RCA-inputs. An input selector, toogles the signal input feed from the connectors to the analog board. The power inlet is high-grade quality with medical standard EMI filter and with voltage selector for operation Speaker terminals are simply made, effective and can handle cables of large cross sections.

PARAMETERS | GaNTubeKT88 MKII |
Nominal Output Power at 0.01% THD+N, 20Hz÷20KHz, 8Ω | 125W |
THD+N 10W/1KHz | <0.005% |
Maximum Output Power at 0.1% THD+N, 1KHz, , 4Ω | 250W |
Bandwidth ±3dB | 5Hz÷100KHz |
Efficiency% | >94% |
Output Noise (A-weighted) | ≤ 45μV |
PWM Frequency | 800KHz |
Dynamic Range | 120dB |
Dimension | 11"×11’x5" (279x279x127mm) |
Weight | 22lbs (10kg) |
Input Voltage | 110-240V (user selectable) |